TES 23.3 - Earth Science Teachers` Association
Transcription
TES 23.3 - Earth Science Teachers` Association
ISSN 0957·8005 Teaching Earth Sciences Volume 23, Number 3, 1998 Joumal of the Earth Science Teachers' Association Guide.. to contributors for the submission of articles Intending authors are advised to inspect back issues of Geology Teaching and Teaching Earth ScIences since Volume 12 in order to make themselves familiar with the Journal's house style for presenting articles. For those with typing and photocopying facilities, three copies of each article should be submitted, Including the top copy. Please use double line spacing and A4 sized paper with about a one inch margin on all $ides. If you do not have these facilities, then one handwritten, legible copy will be accepted, again on A4 sized paper, double spaced and with wide margins. You should use black .,en for good photocopying. SI units should be used throughout articles but where this is inappropriate, a conversion table should be su~ . plied. Longer articles should contain a brief introduction or summary stating the alms of the article. Authors of workbooks or worksheets should indicate time spent by pupils and age-range. Only one copy Is required · for items which do not need reviewing (letters, book revieWS, news, nonconformity, geofun, etc.) If you have access to a word processor or computer, the Editor would welcome a copy on disc (for articles, after review). Tables These should be provided on separate sheets of paperr a new sheet for each table. Figures Prepared artwork should be of high quality and drawn to a size about 50% larger than you require for printing, having due regard to page size and column widths. If you are unable to provide your own lettering then you should include a tracing paper overlay for each figure which bears the required lettering. If you do not have drawing facilities, clearly drawn rough diagrams will be accepted. Photographs These should be black and white, or colour prints and of sufficient clarity for reproduction. Copyright There is no copyright on original material 'published in Teaching Earth Sdences Iflt is required for use within the classroom or lecture room. Copyright material reproduced by permission of other publications rests with the originating publishers. Permission must be sought from the Editorial Board to reProduce oricinaJ material from TeachIng Earth Sdences In other publications, and appropriate acknowledgement given. All articles submitted should be original and should contain the author(s)' full name(s) and address(es). They should be sent to the Editor, Denis Bates, Institute ~f Earth Studies, University of Wales, Aberystwyth, Dyf~d SY23 3DB. Volume 23 No. 3 (1998) Teaching Earth Sciences Editorial 106 Neil Thomas 107 TRANSFERABLE SKILLS The future of Key Skills in Geoscience degree courses: Opportunity and minefield Neil Thomas 108 Transferable skills and the Diploma of Achievement Peter Kennett 112 The Geology of construction raw materials: stone, natural aggregates, cement, brick clays David Roberts I I5 Teaching the evolution ofthe atmosphere at Key Stage 4 Alastair Fleming I 30 (hris King and Peter Kennett 135 John Knill 140 Geoff Nicho/son 142 Keith Moseley 143 From the (new) Chair 'Science of the Earth' - past and present Desert Island Exposures: Usan Peninsula, Jordan The View from My Attic: Notes from your Promotions Convenor Keith's Column Internet News 147 Reviews 148 New Members 154 SHOPFl,OOR: Measuring the Earth's circumference with a yardstick (the easy way) Gene G. 8yrd 155 Cover picture: Hebertella sp. Interior of ventral valve. Mid Orc:iovician. U.S.A. Our World Wide Web Home Page is now maintained by John Grattan, of the University of Wales Abery!!twyth: http://www.aber.ac.ukl-ieswww/ESTAlESTA.htm John has made beginnings in developing the ESTA site. Further develop,. ments will follow shortly. Please bench test the site and let him know. of any problems at jpg@aber.ac.uk TeachingEarth Sciences: vol. 23, pt. 3 (1998) 105 EDITORIAl. RIGS needs you I write this Editorial having just returned from the annual of the W~lsh RIGS (Regionalfy Important Geological Sites) groups, which was held in Machynlleth at the end of September. I was there primarily because I had been asked to lead part of one of the field excursions, to localities in the Aberystwyth are? which we have used for teaching. Though I was on the periphery of the conference, not haVing been involved in any of the Welsh RIGS groups, I was nevertheless reminded of the relevance of RIGS teachers of earth science at all leve.ls, and, further, reminded that we have pUblished articles on RIGS; accounts of RIGS in Wales, England and Scotland (Vol 1811-3), and on assessing RIGS sites, particularly for educational use (Vol. 221 I). conf~rence Have you thought of contributing to the RIGS work? The WEYMOUTH 11)(~ ideal PicldU'OI k Lf?1llre for ('"'/Jesil Beach, Portkl1ld alld the PUlbecks. • All rooms en-suite • Free lecture rooms with video cinema • Substantial meals • Packed lunch available • Many leading schools and universities catered for • Reasonable rates work of identifying .and classifying Sites, of their registration and legal status, and of their conservation, is being carried out by people at all levels of expertise and interest, from amateurs through all the educational fields .to professional. workers: ~ere is an opportunity to participate in geological conservation, and also to benefit from the contacts with all the.se people. Particularly. for schoo[teachers, this offers •. at the receiving end - the· contact· with professional and. amateur earth. scientists which wm greatly. enhance bpththequality of tea~hmg, and other b:er:Jefjrs such as a source of specimens, adVIce, and the occasional visitor to the classroom. There is also the pOSSibility of involving pupils in the work of RIGS groups: even at primary level it should be possible to have groups from the classroom helping in th.e cleaning up, and care, of site~ - and thereby. learning both about their geology, and the Wider lesson of appreciation and care of the natural environment. \~~7{ ~~LiverpOOI John Moores University B.Se. Hono rs Degree i Earth ~cien e Geology and Physical Geography are integrated in a stUdy of the Earth, its environments and reSources. The modular degree scheme offers our students a broad spectrum of options rn Earth Science. Additional subject areas may be studied jointly with Earth Science RAC** RAC** FAIRlIAVEN HOTEL 37 The Esplanade, Weymouth DT4 8DH Telephone: (01305) 760200 Fax: (01305) 760300 Teaching Earth Sciences: vol. 23, pt. 3 (1998) giving flexibility to structure a degree course of thetr choice. Further details from:- NeilBowc:ten, School of Biological & Earth Seiences. Liverpool John .Moo res University, Byrom Street, Liverpool L3 3AF. 106 fROM THE (NEW) CHAIR Continuing in ,my predecessor's footsteps, I am keen to produce some words (albeit limited in their wisdom!) in each issue of TES with a dual purpose: to keep members in touch with the issues that are important to ESTA and to Earth Sciences Education in general, and to let you know what I am doing about these issues on your behalf. Duncan's work over the past few years, supported by other Council members. has left ESTA with a louder voice in curriculum planning than previously known. Therefore, we need to keep the momentum going and to. continue pushing for our subject to feature . strongly in future iterations ohhe National Curriculum. linked to this, of course, is the issue of who teaches our subject. This is particularly important at KS3 and 4. where science and geography teachers alike need constant encouragement and practical help to enthuse students about the most fundamental s.cience of all - that of the Earth. It may not surprise members to know that, being from a HE background, t am interested in the "continuum" of Earth Science education. By that I mean that all sectors - primary, KS3/4, post 16, FE and HE should be looking towards helping qne another with the provision of expertise· and dissemination of material with the collective goal of improving the status and quality of ES teaching. To this end, the ESTA Secondary Committee (through Mick Wright at Richmond CoUege) has teamed up with the HE Committee and Andy Swan and Nick Petford of the School of Geological S.ciences at Kingston UniverSity to design a series of INSET courses targeted at science teachers who deliver the ES content at KS3 and 4. The first of these one-day courses is scheduled for December 1998. It is my hope that this type of approach, already in place at a number of other Universities, will develop a strong bond between the various sectors in the future (and hopefully increase ESTA membership along the way!!). In order to make the "continuum" work. it is necessary to have healthy, thriving ESTA committees and this is another thing I am keen to ensure. ESTA has benefited from an excellent HE Committee Chair for the last two years but Phi! Gravestock has now completed his term on Council. The challenge is therefore to do justice to the tireless efforts of Phi! and Duncan who have helped make ESTA more HE-friendly in recent times. There is still much to do and one of my main priorities (and I make no apology for thiS) is to increase the profile of ESTA in the HE sector. As I write I can almost feel Primary arid Secondary members shuffling in their seats - fear not! Despite my background, I am acutely aware that the lifeblood of ESTA lies in its core membership from the Primary and Secondary sectors and I want to take this opportunity to reassure members from these sectors that I am committed to Earth Sciences education as a whole. It is my fundamental belief that the only way to take Earth Sciences. education forward into the new millennium is to work acrosS the sectors and to produce a body that is the genuine voice of ES education nationally and internationally. This brings me neatly to an issue which I have no doubt will dominate the minds of ESTA members in the months to come and, at the same time, stir up considerable emotions! I refer to the proposed links with the Geological SOciety. Most members will be aware that ESTA is currently in close negotiations with a delegation from the GS with the aim of producing a model. to replace the largely unsuccessfuljESEC. ESTA's delegation is led by. Chris King who is accompanied by Maggie Williams from the Primary Sector and myself. Teaching Earth Sciences: vol. 23, pt. 3 (7998) There are so many issues that I would like to flag ur here but most will wait for the next instalment. However, will plant one further seed in members' minds. At this year's Annu.al ESTA Course & Conference we were treated to superb hospitality, magnificent organisation, a first class INSET, workshop and field work programme and one of the most stimulating and informative invited lectures of recent times, not to mention a highly amusing and entertaining after dinner speech from our own Keith Moseley! AfI in all, it was a thoroughly enjoyable event for all who attended. It is all the more unfortunate, therefore, that so few people could attend the Primary and Secondary INSET days and. more disappointingly. the AGM and Open Forum. The latter provides the opportunity for any and every ESTA member to voice an opinion on any and every issue we tackle in the Association. It was noted by several people who did attend the AGM and Open Forum that the event seemed to lack the healthy debate and discussion of years past and too much time was spent on listening to reports of committee chairs that could have been read in accompanying material. There was a distinct feeling that elements of the ESTA Conference have grown a !ittlestate. These issues, coupled with the timing of the INSET events which precluded attendance by many Primary and Secondary members, have led me anda number of my Council colleagues to take a fresh look at the Annual Conference. We aim to establish what are its most popular and stimulating aspects and how we can consolidate and enhance these. We also aim to highlight the parts that are in need of a re-think, inter ll1 s .of timing and structure and to identify potential new programme items. Questions such as: Should the INSETdays continue to be timetabled on the Friday!,and. Should the AGM & Open Forum be moved from the Sunday to another slot where they can attract more delegates! In order to perform this task effectively, we need the opinions of the membership right across the spectrum - established members. new members, Geologists, non-GeologiSts, Primary, Secondary. HE, Industry members. Let's face it, the Annual Conference and Course is one of ESTA's jewels but clearly it is in danger of becoming stale and therefore turning people away. I encourage (nay plead with!) all members to get in touchwithoneofthe·three Council members (via the Secretary) charged with evaluatin~ the conference programme and give us your ideas and comments. The lucky trio are: myself, NikiWhitburnand Polly Rhodes! As a parting shot, I would like all members to consider two other issues and, if possible. communicate their thoughts to me: The format of TES and the merits/drawbacks of moving towards a combination of a more rigorous journal and· a newsletter as separate publications; Practical ways in which to increase ESTA membership. Conceptually, the Association exists to benefit all its members and Earth Sciences Education across all sectors. Practically, I am not sure that it currently satisfies these points.. Without getting too "touchy-feely", I would like to close by stressiRg that the opinions of all members are very important to me and Iwould like to hear them. We all have a duty to take ESTAand ES EdUcation into the neW millennium,· please help those of us on Council to make sure this happens! Hwyl fawr! Neil Thomas 707 The future of Key SkUls in Geoscience degree cQurses:Opportunity and minefield NeilThomas For many years, HE providers have been told that employersneedgraduates to show ~Yidence ·of vocational (Key, or transferahle).skills in addition to.subje~t knowledge. HE, in .turn. has responded by re-designing parts of degree .courses to· incorporate the required Key Skills training. Recently, however, HE has been under increasing pressure to implement Kc;lySkills according to the. natiOnal framework definc;ld by the National Council for Vocational Qualifications ENCVQ). This article attempts to summarise the NCVQ Key Skills framework; outline some of the relevant issues .and potential problems which could .Iimit its use in HE Geosclences and suggest ways in which the basic concept of the framework could be adopted to the benefit of skills training in HE but without producing the administrative nightmares associated with the full-blown framework. Introduction In a recent DfEE meeting a view was expressed thatthe term 'Key Skills' means something completely different in HE than i~ the secondary/tertiary sector. BasicaUy, there are two defillldons: Key Skiffs (capital K, capital S): containing five areas - use of number. IT, communication. working with others and learning how to learn, as rigorously defined in. the NCVQ national framework and mentioned In the Dearing Review; key skiffs (small k, smalls): the collection ofso-called 'transferable skills' that HE thinks students need for employment. The perception is that, in the HE model, key skills are generally delivered in an ad hoc fashion with littl.e regard for quantifying students' performance and achievement. This may indeed be true but the reality is that the skills contained within the HE model are exactly the same· a~ those defined in the NCVQ model. The main problem appears to bethat the Key Skills framework (capital K, capital S) is far too complex to be embedded in most university modular degree programmes. So, HE}s have attempted to produce models that are manageable within their OWn institutions. This leads to confusion caused by inconsistency of implementation across. the HE sector and breakdown of the so-called 'continuum' of education provision. For some time HE has been criticised for its approach to skills development which, it is claimed, shows little regard to the (apparently) ~ignificant emphasis placed on these matters in schools. In fact. in recent years, little importance is attached to formal coverage of Key Skills areas in the non-vocational courses run in schooJs. Students are made aware of the skiUs areas but performance is rarely formerly assessed. Given that the vast majority of students entering HE to study for Geosciences degrees still hail from the traditional GCSE and A-Level (rather than GNVQ) route, the awareness of the NCVQ Key Skills model in most first year undergraduates has been limited. In reality, there has been no 'continuum' as far as Teaching Earth Sciences: Vol. 23, pt. 3 (1998) Key Skills are concerned but this situ;ltion is set to change. Formal assessment of Key SkiUs wiU soon.be anir1tegral part of A-Level courses which means that studentS arriving In BE will have an increased awareness of the framework and an expectation that. their Key Skills levels of achievemen.t will be enhanced throughout the duration of their degree course. The argument from the educationalis.ts lS that unless HE takes steps to embed the KS framework into degree courses,students will arrive at l.mlversit,y with a multitude .of wet! developed, recorded and eVidenced skills, only for progress in this area to be halted by ourinabilit,y to .take their learning to a higher level or, in some cases, our total dlsregar'dforkeyskills in favour of (perish the thought) subject knowle~e! There~ fore,institutions wil1n~ed to conSider the five KS areas and develop a model that works within their own particular course structures. In this wayXey Skills, which we all know to be important to a balanced HE experience, can be. made to revolve around the subject matter rather than the less desirable, and ultimately unnecessary, inverse. Educational.ists believe that HE curriculum planners must attempt to integrate the NCVQ Key Skills ruodel.intodegree programmes if HE is to train its students to meet tile future demands of lifelong learning and career development. Furthermore, the degree certificate should Include a Key Skills accreditation otherwj~e it all me(j.ns nothing.. Su<:h a regimen. tal approach may ultimately be forced upon us but.this does not mean that it is the most appropriate or ben~ficlal model. In a recent article Norman jackson·attemptedto illustrate the implications of Dearing recommendations for standards in Geoscience education (Jackson 1997). This bad a mixed reception within the Geoscienc.es communIt,ybut,. importantly. iIIustrated.the fact. that lmplemc;lnting Dearing could become a logistical nightmare, which will put off many departments. Incorporati9110fthe NCVQ KS frameworkcouldbe equallyas problematic unless we (j.dopt a simplified scheme. At this point, it is appropriate to outline the KS framework.· Outline oftheNCVQ Key (Core)Skills Frame.. work (source: the NCVQ framework document) Key Skills (formerly Core Skills) are. nationally recognised, competence-based qualifications describing the. essential generic skills that underpin a range of acti.vities in education. employment and life. The awards give credittost!:idents who consistently demonstrate skills across a range of contexts. There are five Key Skills (KS} areas: f. Communication 2. Application 0f Number 3. Information Technology 4. Working with others 5. ImproviRg own learning and performance A sixth area - Problem Solving- exists but is not yet accredited by NCVQ. Each KS area has five levels of attainment, becoming 708 progressively more demanding in breadth, depth and autonomy. Each KS area, at any particular level, is called a Unit. Each Unit is sub-divided into two or more elements. Elements are further defined in terms of: Performance criteria (description of exactly what the candidate has to do) Range (the variety of circumstances in which criteria need to be met) Evidence indicators (type of evidence required) Amplification (clarification of meaning of phrases used in Performance Criteria and Range) Guidance (illustrative examples of how assessment requirements can be met) Candidates produce evidence (from personal, academic or work situations) to demonstrate achievement in each area. The evidence is then assessed (by qualified assessors) and the student either achieves or does not achieve at a particular level. Each level subsumes the previous one so those students who achieve at level 3 have also satisfied the criteria at levels I and 2. However, it is not acceptable merely to demonstrate additional performance to move from one level to .anothe~: all performance criteria should generally be assessed In combmation. Furthermore, the entire range for any level, as outlined In the performance indicators, should also be met in full. In progressing from one level to the next, students should fulfil all elements of the relevant unit, e.g. to be competent at level 3 in Communication, a student must meet the requirements of the elements 'Take part in discussions', 'Produce written material', 'Use images' and 'Read and respond to written materials'. The vast array of terminology makes the framework overly cumbersome and would undoubtedly give rise to problems should it be adopted in HE. The generally agreed achievement standard for each KS area at A-level is level 3, implying that direct-entry students to HE should be proficient at this level. Should HE departments assume this general case to be accurate (in the absence of any formal certification)~ Should we conduct some kind of entry test to set a base line for each student in each KS area? At what level do mature students enter? How can we account for varying entry levels in our course design? The level 3 generalisation also suggests that students should progress to a minimum of level 4 in th.e second year of their degree and to levelS by the e~d. of their third year. Assessment of this would be a loglstlcal and administrative nightmare. If we assume that all students have Level 3 in all areas because they have A-levels, we are immediately introducing problems associated with inaccurate assessment of performance which would make the whole procedure pointless. Another significant problem within modular degree schemes is one of {;onsistency. To ensure that all students hav~ the opportunity to develop all Key Skills, it is necessary to elth.er overload core modules with skills training or to repeat skills training in all modules, neither of which is appropriate. How to make Key Skills work in Geosciences degree courses The key criteria for any successful educational development in HE are to cut down staff time (to release research time) and, at the same time, increase student learning opportunities Teaching Earth Sciences: vol. 23, pt. 3 (1998) without diminishing the quality of the educational experience. So, how do we establish a Key Skills framework that wHl satisfy these· criteria? The short answer is 'With great difficulty!' However, in view of the perceived importance of KS in the future of HE, there is a need to produce a workable model. This model needs to comprise design, delivery and evaluation (assessment, feedback + recording) components. Design The basic element of every model is the design and the key to this is 'mapping' of current provision. Most departments. at some stage during the TQA era, have conducted some kind of 'mapping' exercise to. match the standard skills list~e.g. Thomas 1996) against their course content. Such exerCIses often result in the production of complex course skills maps, grids or matrices which are usually regarded by staff and students as being unmanageable and largely un~ecessary.. Consequentlr, a considerable amount of staff time IS wasted In the production of documentation that will mainly be used as administrative preparation for TQA.type visits. Th~s is both. wasteful and educationally unsound. If these mappmg exercises are to be effective in establishing a KS culture within HE, they must be accepted and implemented by all staff and their use rT\.o~~t()red and evaluated by a staff member with overall responSibility. It has been my experience that one of the reasons for the opposition to Key Skills in HE is the way in which the ~h~le concept is packaged (Thomas 1998) where s~ff, both. JunIor and senior, regard the development of such skills as peripheral to the 'core business' of a department. However, employers constantly remind HE that provision of such skills ~rajriing is of crucial importance. It is therefore necessary to deVise a scheme which can embrace reticent staff whilst still prOViding the necessary opportunities for students to develop and review Key Skills. The scheme must also provide s~ff with simple and effective assessment and feedback mechanisms. One approach has been to devise coursework progra~mes that require the use and development of as many key skills as possible in as few items of work as possible. I have seen one ludicrous example of this approach, fortunately not from Geosciences. where first year students studying a first semes· ter module are given a three week assignment (in addition to attending lectures) which involves: • working in a group to research a topic, . • presenting the results of their work in the form of a word· processed technical report and computer-generated poster presentation, and, • each group member being given a Viva Voce examination. The only reason for producing such a ~kills overload is to ,l=ra.m the necessary training into one exercise and be done With It! No doubt. the module leader will dutifully place a tick next to all the relevant skills on the circulated skills matrix and claim that they are developed and assessed on his/her module. It all looks good in the course documentation .but how can ~e students possibly develop and evaluate their performance 10 such an overloaded aSSignment? This kind of scenario and the vast array of skills elements suggests that it is almost imp?ssible to adopt the.KS framework in its entirety. A solution to the problem IS tobre.ak down the minefield of the KS framework and highlight the elements within each ohhe five (eventually six) KSareas which we believe to be most important and relevant to Geosdences students. Of course, departments may well come up with 109 compl~telydifferent lists if asked to conduct such an exercise . and ·.that Introduces· further· inconsistencies to. the process. On the other . hand, .if a group of ge.osdentists were to get togedierandproducea definitive KS fram~workfor us.e in all nationaJ degree courses we would beaccused. perhaps rightly. of attempting to stifle the individuafityof departments; So, what is the most appropriate courseofaction~ The .answer dependsuporl th~ structure andflexil::Hlity of individual degree courses. For courses which have a significant core element running through thre~ years, the picture is more straightforward and prescription of a Key Skiflsframework (at least in theory) is relatively sirnple.formodular coursesofferirlga large amount ofchoice and limited eoreelement in second and third years, consistency .of assessment becomes a problem. Thea$$~e<l K.eySkills elements WQuld have. to be attached to . CQre modules, with skillsconteFltof Qther modules being a tQP-UP to the required attainment lev.el for the year. This, of course, introduces th~ potential problem of cramming highlighted in the example above .. In t.hisscenario it might be very diffic;:ultto map aprogr~ssion from Level 3 (entry) to LevelS (graduation) in aU KS areas ... The one common element to atl geosciencE~s degree courses is fie:ldwork, an environment that has great p<>tential fgr skills development. An obvious solutionseemstodeSign fieldV(orkprggramm~s that h;IVea.sigllificant element of key skills training and. asseS$ment, thereby redUcing .the requirement to overlo~dother core modul.e5. As. evidenced from the 1997UK Geosdences Fieldwork Symposiumat Lek~ter (ESTA Special Publication), Key Skills can be·embedded within fieldwork with minimal detriment to the subje~ matter. In fact this approach enhances the fieldwork programme by highHghtingthegeneric. trainingaspe~tsln additipn to developing geological knowledge. All KS elements couJdfeasibly be covered. infieldwo.rk but themo~t obvious andrelevaritare probably: • • working with others (KS elements from NCVQ framework; identify collective goals and responsibilities; work to collective goals); communiCation (KS elements: .take part in. discussior)s; prodUce written material; .use images; read and respond to written materials); improving own learning and performance (KS. elements: identify targets; follow schedule to meet targets). In summary, to design an effective framework, departments must: L highlight the Key Skills that are important to itscourse(s); 2. lTlaptlie current skills provision in each module/course; 3. identify learning opportunities tor KS in core modules. withoutoverloadiRg these modules; 4.allocatest!fficiel'lt.KS opporturiitiesto all modules to minimise the problem of inconslstency in student opportunity; 5. prodt,lceaskifls diet that gives opportunities .for ample prpgression of KSthroughout the years of the degree course. Delivery. Assessment and Feedback of Key Skills The delivery and assessment of Key Skills material has consistentlycaused>problems in HE due. to a combination 9f staff unfamitiaritywith the material, lack of interest, lack of relevance to the 'core business' of the department etc .. (Thomas 1998).Oe.spitethese problems,UK HE Geosdentists have developed a large volume of exce:llent material which few people ;lre aware of. In respons~ to this, the DfEE-funded UK Earth .$dences Discipline Network has produced the document Helping Earth Sciences student to Develop Key Skills: A Teaching Earth Sciences: vol. 23, pt, 3 (1998) PortfoliO of Curriculum ExerGises which is. designe~ to help tutors deliver subject-relevant Key SkiHs exerdses .and contains exercises for all fevels·.of a.degree·.course foruse.!Jla range of learning environments. ThisportfoJ!Q isavaitable to .311 Geosciences academics .andis intended .tobean evolving nationat·reSOllf'Ce forGeoscienceeducatiori.[CGPiesareavan~ able from Or Neil .• Thomas. UKEarth·Scienc:~ D.iscipline Network. School of Geologka!Sciences, KingStgltlUniversity, Penrhyn .Road,. Kil'lgston-upon~Thames.Surrey KT I lH.Email: n.thomas@kingston.ac.uk.price £2.0~OO,} Feedback needs to be both specific and. constrllctive ..... Com:ments like "poor oral presentation skiUs"on a feedback.form is not very helpft,lItoa.student - themarkgive1lfor the exercise will tell them that their presentation.has beEm poor! Feedback needstoprovfdeexplicit commentsol"\·what went wrong and constructive advice onexactlyhowth~stU<fent can improve.. Also. positive feedback needs to be· given· on. what went well s.o that the student canconsoHdatepelformance in these areas .. To main:tainquaHty of the feeqbackprocess we, as staff, need to .avoid falling. into the trap. of· providing 'lazy' feedback due to the pressures of our numerousotner commitments. RecordingAchievement In order .to be .fully effective, educationalists believe that a student must have some kind of accreditation for key skills to accompany module and COl,Irse grades. SeveraI HEls have attempted. to introduce Key· Skills certificates orgra.oes on student result transcripts. Alternative models include: L KeySkiUs assessed by way ()f performance in courseworkit.ems(forasinglem9dule) which have specific skills elements attached. Fprexample: Grade 'A' in,CommLj'nication would be. awarqedfgr asclJdent who achieved. >.70% • IIl!llodule.· assigQments·. s:overing/alf· KS elements in the coromuniclltionl;!oit ,defined· in the. .nodule gUide aod key skil1sframework) at theappropf'iatelev~tThis model wouldindude.a l(eySkills~de(s) f(>l".eachmoduIe V(h ich G:ould be recorded onthe$t(:Identtr~cr:ipt~long with the academic grade..for the. module but would rn>t neees$arily be the same as the academic grade, 2. Key Skills grade equated with module grade. For example: If a particular module Is mappedtodev(!lopeltl)eraJ! KeySkins elements or a number of specific elements at.the apj>roprjate level. a student who obtains a grade~,A: in the mooule, will. be deemed to have obtained a grade'A'in Key SkUls~ 3. Assign a .grade to each K~y~ldlls;,a:rea, based on performance a;cl"ossallinodules. For example, see figure I. KS area Communication Application of Number Information Tc,<,hnology Working wilh olhers Improving own ll!tlrning & pert'ornUlm:t: . SmlesrerlYeur gnuJe ModUles useti/o "otaln firade B+ C A GllO IOA,Gll 020B,GUllOOB GlIOIOA.(;UH6HB, MAl W!.!\ GL10201t (,OIOII.B, GLl052B GLI llOOB , GLl.ll20B B All C· modules 110 The list of modules used could be in order of importance in each KS area if reqUired. This model could either use a section at the bottom of the academic transcript or employ a separate transcript to record achievement. A member of staff acts as a committed co-ordinator of the entire process, with backing from the head of department; The process is regularly reviewed and improved at staff! teaching & learning meetings. 4. The inverse of Model 3, where each module has a grade for each skills area. For example, see Figure 2. All of this. of course, will require the time and energy of already heaVily-loaded staff. However, with HEFCE set to raise the profile of learning and teaching in HE, issues like Key Skills will soon need to move from being 'peripheral' to 'core' business in the minds of all Heads of Department. ()I't'mll GLIROOR (Fieldwork) grade References Kn' Skills an'a Communication Apr. Of Number B+ B IT C \Vorking wtlh others Improving own... A+ A- Each of these models has its merits and problems both generally and in terms of specific degree course structures. Models I and 4 are perhaps the most educationally-sound, with skills grades being awarded on the basis of individual pieces of work with well-mapped Key Skills elements. Model 2 only works jf the module originally has a. well-defined and appropriate KS element, covering all reqUired elements of each Key Skills area. This is, however, the least labour intensive of the models in terms of assessment and, as such. may be attractive to course managers. Models 3. and 4 have the disadvantage of being very labour intensive and requ iring one mem ber of staff to assess, in conjunction with individual module leaders, each student's Key Skills performance. Jackson, N.J. (1997). Implications of the Dearing report for Academic Standards in Geoscience Education. Geoscientist, 7 (11),9-15. Thomas, D.N. (1996). The incorporation of transferable skills training within I;arth Sciences degree courses: A case study from the University of Liverpool. In, Stow, D.A.V. & McCal\, G.J.H. (Eds), Geosdence Education & Training in schools and universities (or industry and pUblic awareness, 549-554, Balkema Rotterdam, 855pp. Thomas, D.N. (1998). The UK Earth Sciences Personal and Career Development Network: Final Project Report. Department for Education & Employment. 26pp. Neil Thomas School of Geological Sciences Kingston University Conclusions Anyone who has examined the Key Skills framework document wiHrealise that it is full of jargon, cumbersome and has significant and time-consuming implications for staff training and curriculum planning. As such. it is unrealistic to suggest that we can· adopt the framework as it stands. This article outlines some possible solutions to the problem but is designed, principally, asa catalyst for discussion. Like it or not the Key Skills concept is hereto stay so, ineVitably, HE courses will be asked to adopt some form of KS framework in the notto-distant future. Regardless of the model adopted by individual departments, the following ten generic points are crucial to the success of the concept: • • The adopted model. must be simple, transparent and staff· friendly; There must be minimal disruption to subject-specific training (indeed any model should enhance this training); There must be consistency throughout all years and all courses; Staff must be trained to deliver an'd evaluate the model conSistently; . The model must be designed to offer a diet of KS which allows student performance to progress from entry to graduation; The assessment strategy must be fair and appropriately weighted; Staff must give concise, constructive and informative feedback to allow maximum student development; The l1lechanism(s) of recording achievement must be appropriate and meaningful; Teaching Earth Sciences: VOl. 23, pt. 3 (1998) MEMBERSHIP SUBSCRIPTIONS These should have been paid by the I st October. Have you renewed your subscription? Send your cheque to: Polly Rhodes 96 Chase Road Lindford Hants GU350RR Membership can be paid by Direct Debit 17/ Transferable skills and the Diploma of Achievement Peter Kennett Other articles in this issue of Teaching Earth Sciences will probably concentrate on the ways in which skills learned through the medium of Geology classes may be applied to other walks of life. I propose to tackle the subject the other way rouncland to describe scheme in use at my school which emphasises the skills themselves .and then encourages students to apply them to their A-Lev~ (or GNVQ Advanced) subjects. a We have been using OCEAC's Diploma of Achievement for several years, having become involved initially. as a trial school for "The NortM" Most teachers will know the difficulty involved in persuading students to turn up for enhancement lessons, let alone to get them to ~ke an active part when they are there. We were no exception. and were looking for something to stimulate our students. when we heard of the Diploma: ·'n its early days. it was very much the brainchild of John Lewis. OBE, an inspirational teacher who was formerly Head of PhysiCS at Malvern College. :rhe intention was that it should be fun to do, easy to administer and valuable in the skills which it engendered. The skills were selected in consultation with the universities, industry an.d commerce, who were all too aware of the large gaps in the personal development of many of their recruits. With the coming of the Dearing Review, the Diploma has inevitably attracted more bureaucracy, since it is hsped that it will eventually carry UCASaccreditation and also feature as an "up and running" system of skills teaching. However, it is a lot simpler to administer than several other current systems of examining, and when dealt with properly is mostly good fun. The intention is that Diploma work should be handled mainly in tutor groups, w.ith the Form Tutor acting as a facilitatoras much as a teaCher. However, points for the certificate may also be gained from within other lessons, and A-Level Geology presents many good opportunities. I have found a useful interplay between Diploma requirements and those of the Geology lesson: for example, if students have been shown how to give a "presentation" before they come to. do one in Geology, the result is usually better thanifthey have had no experience. It also pr.ovidesauseful 'carrot' ifthey know that I shall be making a brief written report on their performance to the Form Tutor. Although the format of the Diploma will shortly be changed somewhat, to dovetail with the implications of·the· Dearing review, a brief summary is· given below, abstracted, with permission, from the Diploma of Achievement Handbook (Figure I). Most of the eight categories of skills are subdivided into four TIlE STRUCTURE OF THE DIPLOMA • There are two essential elements in the Diploma of Achievement: SKILLS and THEMES • The Diploma comprises a maximum of eight categories of SKILL. These are: 0 communication: language skills 0 research and investigating skills 0 communication: presentation skills 0 designing and making skills 0 organising skills 0 computing skills 0 numeracy skills 0 survival skills NOTE: To receive a Diploma it is necessary to qualify in a minimum of four skill categories of which two must be the two categories of communication. • The Resource Package [Volumes 1 and 2 or the CD ROM version) covers an extensive range of THEMES in which skills may be developed. These include:- Figure I 0 communication 0 money matters 0 survival skills 0 information technology 0 business in the conununity 0 understanding Europe . 0 numeracy 0 legal matters 0 projects 0 learning to learn 0 health issues 0 philosophical issues • Centres can use topics and activities of their own which may augment or replace the above. These may include schoollcollege/community activities, work experience, visits, ~d fieldwork expeditions. The Diploma can thus provide a coherent framework for extracurricular activities as well as formal 'classroom subjects'. Teaching Earth Sciences: VOl. 23, pt. 3 (1998) 112 further divisions. For example. the Communication:Presentation Skills section is broken down into: Making a presentation; Note-taking: We usually attend several outside lectures during the A-Level course. given by university lecturers or at meetings of the Yorkshire Geological SOciety. Notes may either be taken at the time, or retrospectively, thus proving that some of the material went through the mind of the student! (Myown lessons are so anecdotal that I could never use students' notes arising from them for assessment!) Speaking skills; Presenting numerical data; Discussion skills In each of these. a student is marked on a 2,4 or 6 scale, e.g. Making a Presentation . 2 marks: The presentation is complete. 4 marks: The presentation is complete. and is interesting and competent. 6 marks: The presentation is complete. is interesting and competent. and is confident, enjoyable and appropriate to the audience. Writing skills and Reading skills: These are readily assessed from a range of work. and students usually have enough opportunities with their Form Tutor. Communication: Presentation skills Making a presentation; Students give an illustrated presentation on a volcano of their choice, fairly early in the course, which provides a good graphic topic for scoring a "6". They have. also recently drawn up posters on different sedimentary environments and then defended their poster in front of the class. Other opportunities arise from time to time. To try to ensure uniformity of standards. the school has devised its own re- I have found it possible to accredit skills in Geology in some of the following areas: Communication: language skills Ustening skills: Judged on the nature of questions asked and interest showll whilst being shown round an opencast or quarry site by the Manager. To: Subject teachers Diploma te.chers Diploma Presentations Please help us to record 'evidence' for what is essenhally a verbal aspect of the Diploma course Name of student Form Title of ptesentatlOrr Brtef synopsis of coverage: Approx. tength of presentation Did student work: as one of a team Old student use ~Iackboard solo. OHP. TV clip other visual aid V'Jhat was audience reaction like: Please aUocate maTKs to as many as appropriate of the following criteria COMMUNICATION:PRESENTATJON SKILLS Mark Notes (1-6) MAKING A 2 4 As 2, and the The presentation is complete 6 As 4, and the presentation is conftdent enjoy.mle and appropriate to the aiJdience presentallon. is interesting and competent SPEAKING SKillS 2 A 'message' is adequately communIcated : !s 2, and the 'message' IS conveyed !ucdly In a clear VOice ~s 4, and the 'message JS conveyed With , comp-lele conftdence and I: j con . . u:tion PRESENTING NUMERICAL DATA ::r····.·--········,-,.---·.···.,·.·----·------····",,··-.-............................. Able 10 prepare numerical data adequately for a presentation DISCUSSION SKILLS i····································· Ab1e to participate jn group dtscussion -;-"6" ; As 2, and able to prepare j As 4, and able to present f the data In the most ! numerical data in an appropri3'le form ' interesting and confident ~ manner "'T"4'"'' . .... "'Ti5'"""" t As 2. and the l contributiOn has. some ! substance relevant to lhe disCussion ! As 4, and ha~ an ability j to develop and J Of i challenge ideas of others from .. OrganislnUM1!.J. .. · WORKING IN A tEAM Z- Makes 8 contrIDution to the team ,:" ................ ····················-;-·6··· \ As 2. and shQW$ sensitivity to others in i i theleam l As 4 and the j contribution enhances t the performance of j others and so adds 10 j the spml DJ the grOllp Signature of subject leacher Date Please- return this form to the ,student for submission 10 hJslher Fonn Figure 2 Marks transferred to student records by form "TmOl Tutor lor filing for the Dlpfoma course o Teaching Earth Sciences: VOl. 23, pt. 3 (1998) 173 cording sheet which is completed by the subject teacher at the time of the presentation and given to the student for the Form Tutor's files (Figure 2). Speaking Skills: This section is distinct from the above skill and relates to the aUdibility and conviction with which a topic is delivered. It is assessed at the same time as the presentation. Presenting numerical data: This is almost always done. badly, with facts and figures, e.g. about volcanic eruptions. being rattled off at high speed. Through listening to the others. students soon realise that tpeir own delivery was poor, and hopefully improve next time they have to perform! Discussion skills: These can be covered in almost any lesson where group discussionis involved: It is also assessable. when a student is discussing a J>lan for an investigation, for example. Organising skills Managing time; Working in a team and Decision making skills: These are all possible areas for assessment during a wide range of fieldwork and lab work. I have not yet tried assessing the fourth criterion, Managing people, in a geological situation! Numeracy skills Handling numbers; Using graphs and Handling statistics: These can all be covered in investigations such as sieving sediments t9 determine their sorting and their possible origin. Recendy~ some students plotted graJ>hs of the size of vesicles against distance from the margin of the pillow lavas at Strumble Head, in an effort to find out how they cooled. I have not tried to assess Handling money in a geological context, but perhaps I shall watch to see who is the first to run out of pocket money on the next residential field course...! Research and investigation skills Planning skills; Research skills; Investigating skills and Analysing skills: The criteria are very close to those required for A-Level geological coursework and two sets of marks may often be allocated at the same time. Designing and making I haven't tried this one in a geological context yet. a/though there is no reason why an elaborate. design for a piece of equiJ>ment for a geological investigation should not be counted for the Diploma. The other two areas are assessed rather differently, with points being allocated on aUcan do" basis. Computing skills My uSe of computers in class is minimal. However, students are encouraged to use a machine for production of coursework and cancoUect marks for Diploma by doing so. Latterly, I have been handed some excelJentcomputer-generated graphs, (some of them in colour!) covering such themes as porosity measurements and sieving results. stomach i.e. cooking, hygiene, castings etc. I.havenot foun( geological ways of testing these. although some students have been encouraged to qualify in First Aid (for thebody)~ which i~ always comforting to know during field work..Thel!earest WE have come to assessing cooking waS in awarding a "6" to thE grandma of one student, who made a quantitY of rich frui1 cakes for our recent field trip, in order. to .heJp keep cost! down! Reading the above may give the impression that the Diploma is all aboutcoHecting Scout badges, rather than being seriousl) concerned with .the personal devetopme~t of a student anc equipping him or her for life beyond school. In so far as the Diploma is fun to do, there is a good d.eal of truth in this, bU1 it makes a welcome change from the minutiae ofexaminin~ techniques which my GNVQtoUeagues tell me they have tc endure, and works out just as accurately in the end! Scope must also be provided for teaching some of the skills not simply assessing them, although our most successful Form Tutors have discovered that it pays to start assessment as soon as possible, partly to buildup the fife, but also tc encourage learning a skill in a purposeful way. On the occasions when 1 have had to stand in for an absent Form Tutor. I have found it helpful to use video dips of other people giving presentations.. One source of rnaterialis the video supplied by OCEACfor· trainil1g teachers, and showln!! several sixth formers giving brief presentations on topics 01 their choice. Most of them are fairly predictable and only a few count as memorable enough for a "6". 1 then show an excerpt from the 1995 Christmas Lectures, "Planet Earth, an explorer'S .guide", given.by Dr. JamesJackson. Students (who are mostly not ge.ologists) are unanImous in giving Dr.jackson a "6+". When asked to analyse the excerpt, they realise that part of the succeSS is due to having readily available, not only two technicians, but also a range of custom built gadgets, superb 5J>ecimens. and access to video dips. However, they also acknowledge that the main ingredient is the obvious enthUsiasm of the speaker and hi~ delight in his subject. That, at f~ast, can be emulated by a school student on a fow cost budget! Perhaps the biggest benefit is that students become more aware of the range of skilJs which they heed in. their own subject areas and are more Willing to work at improving them. I still have the notes made by a fellow u/1dergraduateduring my first seminar talk at university. ] thought .1 had made a good showing - the topic was black shale ehvironments -until f was handed the notes later. They read, "Mr. Kennettstands up to speak... cough, cough: um, er..... black: shaJes.,..•<x:cur at the bottom of the sea....... " and so it went o.n. I stjll cough. I have forgotten all about thesignifican<;e ofblacks:l:tafes, butt like to think that my presentation skiflshave improved a bit since those days. The process would have been a lot quicker and less painful if only I had done the. Diploma of Achievement.. .! Those interested in finding out more about the Diploma of Achievement should c0t:ltact the Project Direttor, ,Mr. 60b Burkilf, or the Board's Officer llc Diploma of Achievement. Dr. Paul Beedle. Oxford and Cambridge Examinations and Assessment Council, /, Hills Road, Cambridge, CBI 2EU. (Tel 01223-553311). Survival skills These are engagingly titled First Aid for the body i.e. normal First Aid; First Aid for the Home i.e. household maintenance, such as changing tap washers etc.; First Aid for the car and First aid for the Teaching Earth Sciences: vol. 23, pt. 3 (/998) Peter Kennett High Storrs School Sheffield 114 The Geology of construction raw materials: stone, natural aggregates, cement, brick clays I. Introduction David Roberts This article is based on David Roberts' second contribution to the Keele Conference in 1997, and should be read in conjunction with his earlier article on ELEPHANT COUNTRY: the search for Mineral DepOSits. Mineral Coal: Deep-mined 19H3 1992 1991 1994 73357 18636 22()9 65800 507 50457 17006 736 31854 16804 :l13 Other (bl 86 147 50378 255 78 190 51197 306 69 212 60223 319 22ti 64 :108 :159 erudeoi! Onshore Offshore 3703 83129 3962 85222 3737 90213 4649 I 14:lH3 171 4896 157 6082 210 7697 Optlncast Other (8.) Natm::a! gas and oil: Methane (oa equivalent) Collwry Onshore Offshore C-oudenaates and {}thct (c) OnShON:i Iron ore Non·ferrous ores {m~tal content): Tin Le-ad Cop(Wr (d) Zinc (d) Silv ... (e) (kg) Gold (kg) Chalk (1') CO-rumon clay and shale (p) Igneo•• rock (l) Limestone (excluding dolomite) Dolomite {excluding limestone) Sand and gravel: Land Marine {j) Sandstone Slal.e(h) Ball clay (sale8) Barytes China clay (saies) China stone Diatomite (n) Fired.y (p) Rock ,alt Salt from brine Salt in brine (m) Silica sands Talc 59 31 1.1 1.3 2.0 1.01 2.2 l.Oi 1.9 2.0 10317 13050 53948 94861 19454 12155 57654k 89399 18539 82037 16874 14890 326 729 744 77 4 867 (g) 9171 89311 17053 16607 360 8 2 5 291\ 6 0.2 Chert and flint (f) 6:~ 2.3 1.0i 0.3 Ll 565 86 Calcspar Celestite Fluorspa.r Fuller's earth (sales) Gypsum (natural) (i) Lignite Peat (OOOm 3 ) Potash (0) 153 4275 Offshore IB 187 78 189 2500 3 1561 825 1635 1320 3874 4201 11 This is an attempt to compress the salient points of what is a final year Module on a Degree Course into a manageable framework to be used in schools. At a more advanced stage this topic forms an M.Sc. course at Queen Mary College. London and is well covered in an excellent book by J. E. Prentice. Commercially, Construction Raw Materials are big business and by volume are by Thousand far the largest contributor to tonnes mineral production (including oil and coal) in the United Kingdom as is shown by the statis19H5 1996 1997 tics in Fig. I. In terms of value they are outperformed only by 35150 32223 30200 the energy minerals, oil, gas 16369 16315 16900 and coal (Fig. 2). Yet, despite 1518 1658 IlIOO their importance in our lives they have been ignored in al52 49 304 362 82100 most all U.K. Geology Degree 70407 B3872 :179 437 Courses though it is encouraging to note their inclusion in 5051 5250 119500 116743 116524 A-level syllabuses. I will leave you to ponder on the reasons 221 8064 7900 8:109 behind this omission since I 1.1 1.2 1.2 would prefer to keep my council on the subject. at least in 2.0 2.1 2.4 1.6i 1.8i Z.O print. 9078 10891 57766k 93727 17985 10236 12464 56494k 106626 17616 9949 13930 57205k 94636 11966 9239 11804 50705k 86564 16555 83698 16319 91450 17969 18974 402 83293 18439 19796 275 78173 18204 17522 408 16059 462 2 2502n 8 0.1 572 3 1506 883 1400i 1300i 3401 3615 5 12000 50566 102800 99850 17500 250 746 55i 3 2 825 54 i 893 85i 880 93 900 24610 7 0.2 479 2530n 8 0.2 679 58i 13. 2000 2 1982 25860 9 2281n 8 2400n B 708 55 i 132 2000 536 65i 7() 76 189 2500 9800 187 2500 3 1452 941 1200 • 1300. 4076 3587 5 Slurry etc. recovered from dumps. ponds, rivers etc. Biogas from landfill and sewage. c Including ethane, propane and butane, in addition to condensates. d Content 0{ mixed (:oneentrate. Silver content of copper-zinc and lcad~zinc concentrates. Great Britain only. g BGS estimates based on data from producing companies:, h Slate figures inc1ud~ waste used for constructional fill'and powder and granules used in industry. BGS estimal.e. Including marine-dredged landings at foreign porta (o'portal; see p.5-16. k Excluding a smaU production of granite in Northern Ireland. 966 933 17QOi 1300i 4009 4038 5 1800i 1300. 3548 4344 4 2000 1885 1030 22001 1300i 3512 4861 5 560 g7 140 2000 945 1800 1300 3500 4800 6 1 In addition, the foUowing amounts of ib'l1e{1US rock were produced in Guernsey tthou8.!).nd tonnc-s): 1991: 288; 1992: 151; 1993: 180; 1994: 192; 1995: 184; 1996: 198. m n o p Used for purposes other than salt making. Dry weight Marketable product (KCI). Excluding 11: small production in Northern Ireland. Sources: Office for National Statistics, Department of Trade and Industry, Department of Economic Development (Northern Ireland), Crown Estate Commissioners (marine sand and gravel produced fot export), AdviSOry and Finance Committee (Guernsey), and company data. Teaching Earth SCiences; vol. 23, pt. 3 (1998) 2280 143 74 Superficially they seem to lack glamour. and this is not surprising when mineral dossiers are produced with such titles as "Common Clay and Shale". though in reality there is nothing common about many of these materials since they must all meet stringent quality control parameters. Until I developed an interest in the commercial side of geology and met geologists in the Extractive tndustries, from whom I have learned a lot. I used to think that most rocks were suitable for aggregates. Like most people I did not give a second thought to the fact that all the bricks used on a house could be produced to same size. Figure ,. UnitedKingdom 1>rodu,tion of minerals 1991-97. Ref>roduced from United Kingdom Minerals Yearbook '991 by 1>ermission of the Briti$hGeo/og;. col Survey © NERC. All rights reserved. 115 £ million Mineral 1989 1990 1991 1992 1993 1994 1668 1995{b) 1996 4183 2298 293 7089 3918 2546 310 8098 4050 3162 437 7468 3692 3221 428 7306 2531 3424 614 8096 4171 654 9162 1862 4587 739 9875 1768 5295 749 11850 0 19 7 0 11 8 0 7 0 1 0 0 7 0 0 6 0 0 7 0 0 8 1 Sand and gravel LiInestone and dolomite Jgneousrock Sandstone Challl. 583 574 223 78 46 543 594 241 78 48 459 529 224 67 43 425 486 245 65 38 440 514 250 74 38 489 596 248 91 44 491 618 244 94 45 473 577 247 90 47 Common clay and shale China clay Ball clay Fuller's earth 30 216 23 15 26 203 26 15 22 204 26 14 21 213 29 14 22 230 35 15 26 220 40 12 24 230 43 12 19 218 43 14 Salt Silica sands potash Fluorspar Gypsum and anhydrite 33 46 60 12 24 37 43 63 13 22 48 46 64 10 22 49 36 185 9 18 62 40 83 7 18 188 68 51 36 71 9 18 58 84 6 20 57 93 8 22 Miscellaneous minerals 29 22 28 25 22 28 29 32 15881 16865 16931 16395 16497 17865 19256 21796 4450 10298 28 3918 10954 19 3803 10392 8 3323 9860 6 2205 10570 6 1426 11955 5 1553 12678 6 1430 14477 7 2119 1974 1696 1567 1590 1713 1823 1719 16895 16865 15899 14756 14371 15099 16060 17633 Coal Natural gas N at;lral gas liquids Crude petroleum Iron ore Tin Other non-ferrous metals Total At 199() constant prices (using GDP deflator) Coal Oil jUld gas Metals Construction and industrial minerals Total a Calculated on anex·mine or quarry basis. 7 Source: British Geological Survey. b The values ofproduction presented in this table are estimates made by the BGS using a variety of da1;a $Ources. For 1995 selected data from the Prodcom inquiry (an EU statistical inqurry on the volume an~ value of products fo: sale) ha.!) been used for the first time for construction and industrial minerals. This has resulted (or ~rtainminerals. particularly salt, in an apparent ino-ease in the value of production that reflects priInarily the source of the information rather than a real increase in the value of produciion. Figu~ 2. Approximate value of minerals produced in the. United Kingdom '989 .. 1996. Value;s calculated o.non ex-mine or quarry ba$is. Reproduced from United Kingdom Minerals Yearbook 1997 by permission of the British Geological Survey © NE-RC. All rights reserved. shape and colour. The assessment work, with rigorous quality control procedures. of the clay is vital to this end. It is true that construction raw materials are widelyavailable in Britain,but many ofthem happen to be in attractive recreationalareas such as the Peak District. Others for commercial reasQnsneed to be close to locations of usage because transport casts are high and the price of an aggregate. for example, Can doubleiftransported 15-20 m·iles. A visit to your local builders' merchant (or if YOll are rich the local garden centre!) will show you the range of prices for loose gravel for drives or gardenareas.J bought some Staffordshire pink gravel recently at. £ 16· per .tonne but I. was offered a yellow flint gravel from the South of Engtand at 3 times the price. No doubt in Hampshire, Staffordshire Pink Gravel is 3 times the price of the local yellow flint gravel. In regard to the location of these materials one o(the· main obstacles to be overcome by the extractors Is Planning Consent. Recreational areas are valued for their scenic beauty by holidaymakers who are content to clutter the landscape with their caravans but object toa quarry Teaching Earth Sciences: vol. 23, pt. 3 (1998) on the horizon even if it does provide employment for the indigenous people. Near towns and villages problems of noise, dust and traffkresultingfrom mineral extraction can be a problem and must be reconciled. A clay or sand pit ora hard rock quarry canon/y be sited where·that mineral exists and jfthatmaterialisneeded by a consumer it cannot be won elsewhere. Since vveliveinhouses and drive on. roads we all are. thecon~umers:theextraction company is the "middle. man". ReconcHingthe·. contlictof interest and competing land use coupled with other planning matters can occupy .avery large proportion of the working week for a geologist in this industry. In my other paper "Elephant Country" (Roberts 1998) I likened the search for metalliferous mineral dE:lposlts to the hunt for the "Big Elephant"-quitea romantkncrtion. To maintain the analogy 1suppose the Construction Raw Materials could be compared wjth farm animals- there are plenty of them. We know where most of them are but is the quality 116 acceptable? This is not quite as romantic as an Elephant hunt but is a lot more relevant to our lives. The following brief overview should provide many examples of the importance of quality control and testing of these materials. each aspect of which is directed to the end usage. At the present day the use of stone can be grouped under three major headings: Dimension Stone. Slate, and Armourstone. Different properties of the natural stone are required for each usage. 2. Construction stone a) Man has always used stone for construction and a visit to Neolithic sites in Britain will demonstrate this point. From Chysauster in Cornwall to Skara Brea in Orkney the use of natural stone to construct dwellings can be seen. The rocks, of course. are different because the local geology is different and thi.s shows how early man made use of the materials around him. Whether it was the granite of Cornwall or the sandstones of Orkney, what was of importance to early man was the way in which the rock split along natural discontinuities (bedding or joints) into manageable sized blocks. On a more dramatic scale the Pyramids of Egypt and the Inca City of Machu Pichu both utilised this feature in the rocks and it must be remembered that both these were constructed by fitting the rocks together without any cement. The development of the use of stone follows the progress of civilisation and all the great Ecclesiastical buildings in Britain used natural stone. One must not ignore the use of the pure white Carara Marble by the Renaissance architects and sculptors and on a world-wide scale the use of stone has been extensive. Stone which is cut and dressed into regularly shaped pieces is referred to as Dimension Stone and these can have a variety of sizes. The larger blocks can be measured in metres in 3 dimensions though smaller blocks would be reqUired for such uses as pavement curbs. Possibly the best known use of dimension stone is for ornamental purposes where slabs not much more than a few centimetres thick but up to one or two metres in the other two dimensions form a cladding on the main construction or as floor tiles.. These rocks are mainly polished before use. mil~on tonnes 3W~------------------------ 300--- -----. - 250 __________--, ..--- ..- - . - - ...- ..- + - - - - - --1\-. Dimension Stone A good exercise to set VI formers would be to visit the town or city to note the extensive use of dimension stone and to try to identify rock types and consider the properties of those rocks which made then suitable for that purpose. Whilst a visit to the local cemetery could also demonstrate the ornamental use of rock, possibly contact with a monumental mason or marble yard may be more appropriate. Students should also consider how well the different rocks have withstood weathering. From this study they should have noted that a good Dimension stone should have: I. Structural strength to carry the reqUired load without failure; a very important factor for stone used in foundations of dams or bridges. for example. 2. Durability. It should resist exposure to the atmosphere and ground water. Porosity would be an important factor here, particularly with freeze-thaw·cooditions. 3. Attractive appearance particularly when polished. Larvikite, for example. which was extensively used by Burtons, is very attractive when polished but looks rather dull when rough. , 200 , x . x x x I( x ~ : x xxx:x_x : = : Jurassic limestone x ----- - - - - - - ------- - ----- - --- ---------------. -. , ~ ~ Permo· Tflas sandstone x x x x -------- - --x - ------------- --- ----------------- . Perrruan magnesian hmeSiOf'le ---~---------------------------------------- x x x I( ~ x ~x ~ x Carbcmierous sanostone (P ~ Pennant sanOStOne} ~ : J( ~ .. ~ x :x x p ----------------------------------------J( ____________ .: __ CacbonrferQus limes.cne ~_D__ ~ _________ Q.::Q.01."!!'~ _______ _ Pa1aeozoJc slq.-fe (+ ;:: normal to cleavage) W+---------------------- ______________+__ x_ _ _ _ _ _ _ _ _ ~ _ _ _ _ . 1 __________ _ ___________ ~_~ __~_ ~ ~~~ __ ~i . . ___~___ __ . :. __ ~_~_ ;Cl ~. JCr .lOt ~i cvl IG I POI %f'OCr 1Cl tl!:)IJoil:IQt 1!~IH:rOlflOqaoH!lUt~:.C.~J():J()::.u:.:!-Qt:t':> Wk • Mod. stron<;l MOdwk Figure 3. Great Britain production of natura' aggregates 1965-1'97. Reproduced from United Kingdom Miner8lsYearbook 1997 by permission of the British Geological Survey © HERC. All rights reserved. Teaching Earth Sciences: vol. 23, pt. 3 (1998) Slfong Very strong Extremely Slrcng Figure 4. Unconfined compres,ive strength (UCS) of British Rocks. From Prentice 1990, figure 3. I, page 70 © 1990 J. E. Prentice. Reproduced with kind permission from K'uwer Academic Publishers. 717 4. Ease of quarrying and dressing (cutting and shaping into the" required product) - this would be>bestnoted ina quarry but .even in· its place of usage. the rock should reveal information on this. Much dimension stone is won Without the use of explosives since these shatter the rock and hencCe well spaced discontinuities assist in quarrying. Examples of rocks used as Dimension Stone are: Granites: To monumental masons this term frequently includes dolerite, granodiorite and even basalt ("Black Granite"1). Marble: Amongst the most attractive of stones particularly some of those from NorWay with pink and white calcite, the fosterite marbles of Iona and Connemara in the British Isles and from Vianna do Compostella in Portugal. Umestones(often classified as marble.inthe trade). Cotswold Stone, Portland Stone and Pur beck Marble are obvious examples but some Crinoidallimestones of the Carboniferous and Devonian· Limestones must not be excluded. These are but a few examples to set the scene and no doubt you will be able to identify many different ones, including imports, within your local area. b) Slate This is a ·fine grained rock with a good slaty deavage and which can be cleaved and cut into thin well shaped pieces. It is important that. post-cleavage joints are not closely spaced otherwise the resulting pieces would be too small. In Britain the classic slate area is North Wales. whose slate prOVided roofing material for Victorian Industrial Towns and export. Other important slate production is from Delabole Quarry in Cornwall and the Lake District. Some slate productions is as a Dimension Stone as evidenced by the ubiquitous slate gravelitones, fence posts and walls in NorthWa1es and the attractive cleaved tl,lffs oftheBorrowdale Volcanic Rocks produced by BurJingtonSlate in the Lake District. Slate does not take a good polish but the sedimentary and tectonic structures displayed on a coffee tables made of Coniston Slate make it make it an interesting topic ofconversation for us no doubt, but it probably bores our visitors. c) Armourstone Armourstone or Rock Armour requires very large durabl.e rocks, some of which can weighas much as. 20 tonnes each. A major use is in Sea Defences or Breakwaters where they are employed to take the main forclil of the sea to protect a weaker shoreline, Although cQncn:~te is the main material in sea defences (95%), the remaining 5% still constitutes a substantial resource requirement. It is often stated that ideally the quarry to supply this material should be close to the point of usage but this cannot easily be achieved in all cases since shore lines. that need to be protected by Armourstoneare normally composed of weak rocK. A good example is the offshore reefs built from granites, gneisesand larvikitefrom Norway to· protect the beaches on the N.E. Norfolk Coast. Shipping· rock across the North. Sea from a coastal quarry is much cheaper than/and transport from a quarry in Britain. To bea suitable armourstone the rocks must have the following properties: i) ii) Must not be badly fractured otherwise they will fragment easily Must have excellent strength and durability TeaChing Earth Sciences: vol. 23, pt. 3 (1998) lii) Must have a very g()od resistance to weathering. A coastal super quarrywrrently beingasliessedby Tarmac in SOlJthern Norway is .likely toproduce~oodarmourstone. The rock is anorthosite with wide spacep fractureli and in addition to. the above properties also has the advantage for this usage in its being heavy. Thelocatiohin~flord well protectedfrom storms and with nO tidal rallgecoufd make this quarry a major supplier of good durable. rock to much of Northern Europe. . Compare this example with th~ sUPer quarry proposed by .RedlandAggregateson the hie of Harris also to exploit. anorthosite.ln Norway opposition. to the qlJarry is. nOfl"existent, there are no restrictions. on hours or number of days the quarry can be worked and th.ere are many more days. in the year when weather conditions would permit the loading of rock onto ships. Harris cCan experience hign Seas and strong winds for days on end whereas in Norway there is protection In the fjord. Searing in mind the level of opposition to quarry development in Harris as an additional factor which site wolilcl you choose? Good Armour-stone can. be produced from granites and Jimestones if the joints are widely spaced or from sandstones if they are formed asa result of pressure solution lithification rather than aweakbondin.g cement. In order to establish the quality of a rock forarmourstone a thorough petrogtaphic examination is reqUited so as to ensure that flowe;:tk minerals such as clays or m icrofractu res, which would open up under weathering, are present. Should the Severn Barrage ever be constructed blocks of rock armour with a side dimension of 3 metres will be reqlJired on the seaward side. An interesting class exercise wou1d be to look at a map· of the British Isles and consider if a rock with these properties exists on shore. One possibiUty Is the Land's End Granite, orSciUy Isles Granite lIthe joints areJarenough apart but just think about the opposition there. would be to the development of a major quarry in those areas for this purpose. A more likely source of suitable natural armourstone would be Scandinavia or Eastern Canada. However, the alternative is concrete caisons built on shore to the required dimensions and then floated into position );0 be filledwith rock for fill. Floating out concrete caisonsis not a new idea as evidenced by the remains of.theMulberry HarbQuron the beaches of Aromanche on the Normandy .coastwhichwas. designed to protect the landing of troops and equipment on shore after D Day. Unfortunately, the winds and sea strength were underestimated and the construction, though g60d . in concept,.did not have the desired effect. This isanotherfactor that the designers oh Severn Barragewould have to consider and furthermore when~: would the aggre~te for such a large volume of strong c6ncreteand rod~ fill be.sourced?Thereare limestone headlands neat Weston-Super-Mare bvtl for one .doubt if the National Trust which owns some would be too happy to see a headland gradually disappear only to be replaced ac:ross the Bristol Channel. 3. Coarse aggregates Coarse aggregate is defined as particles over Smm in wameter and is used as a primary ingredient in concrete, in );he body of roads or when bound with bitumen as the surlacelayer on roads and runways. The potential resources of bulk aggregate in Great Britain are enormous andVemay (f976) estimated a resource of 7300)(.109 t<;>nnes of hardn,)ck. This will not hav.e reduced ~ignificantlyoverthepast 20 ye~rs.lt is a cheap plentiful material easy to extract, requires little processing and is the basis of our construction industry. Figure 3 shows the 178 level of production of natural aggregates since 1965. Note the high volumes extracted during the "building boom" of the late f 980s and the effects of the recession that followed. Although the price of the aggregate at the quarry gate is low the cost of transport is high for this bulky, heavy material and is the biggest element of its cost on site. Sources of aggregate therefore need to be close to the point of usage and if this is not possible they must be accessible by cheap rather than expensive freight. Marine transport from Sc:otfand or Norway to S.E. England would be a lot less than road transport from Derbyshire or Cornwall. One of the major factors that . has been responsible for the extensive exploitation of the Mendip Hills is that it is the closest surface hard rock in Britain to S.E. England where no surface hard rock exists but where there is great need. The Mendip Hills also provided much of the material for the M4 and MS. A particularly large size aggregate is Rock for Fill though some sources claSSify it under stone. It is rock in an unbound state which is used to create a foundation rigid enough to bear the reqUired load and is free draining. Sub-layers in roads are constructed from rock fill as is much of rock-fill dams. Since this material forms the drainage layer in constructions, it is critical that the rock behaves in a similar way when wet as it does when dry. Shales, clays and any sort of mud rock in any quantity (however small) must be avoided since they can fill voids (and hence impede drainage) and can swell when wet thus causing heave or other deformation of the sub-base. In Britain the quafity of rock for fill in road sub-bases is dictated by the Department of Transport and those roads which carry consistently a high volume of heavy loads must meet stricter quality parameters than those which carry lighter and lower volume traffic. The role of the geologist is to ensure that the rock used meets the required criteria and quality monitoring is necessary to avoid litigation if something goes wrong. This is particularly so if artificial material (furnace or foundry slag) or secondary material such as crushed concrete, bricks or burnt colliery shale (where the clay minerals have been thermally "metamorphosed") is used. Aggregates form the bulk of concrete and the properties of the aggregates will dictate the resultant properties of the structure which has been constructed from it whether it is a high-rise building, a road, a bridge. a dam or the floor of a warehouse. The aggregate must bear the load, be resistant to the environment in which it is employed (i.e. does not degenerate rapidly if wet or under freeze-thaw conditions) or remains rough on the wearing surface of a road so as to prevent the road developing into a skid pan. To predict the behaviour of aggregates a series of laboratory simulation tests have been designed to predict the behaviour of aggregates in their place of usage. In Britain these are prescribed by British Standards. BS 812; BS 882, 120 I; and in the United States by the" American Society for Testing Materials (ASTM). In continental Europe different standards apply for each nation and whilst the same parameters are evaluated the tests differ in detail as do the national specifications. Some rocks which would not pass British specifications may be perfectly acceptable in France. Many properties of the rock are tested and whilst a rock may not have the full properties for one usage it may be perfectly good elsewhere. The more stringent the criteria that have to be met the fewer the rocks that can aCtually meet them and hen<;e those that do can command a higher price and travel further. The following are the main properties tested. Teaching Earth Sciences: vol. 23, pt. 3 (1998) a) Strength This is the ability of a rock (or other material) to resist compression which is of most importance in the construction industry. The compressive strength measures the load bearing capacity of the rock and is carried out in the laboratory by applying pressure in one direction to a cored cylinder of rock and recording the pressure at which the rock fails. This is referred to as Unconfined Compressive Strength (UCS) and is uniaxial. Fig. 4 shows the UCS for a range of British Rock. The weakest rocks used as aggregates are the Jurassic limestones where the three cleavages in calcite prOVide multiple lines of weakness. Weak Cement is responsible for the lower readings for the Permo-Trias Sandstones whereas the Carboniferous Sandstones have a stronger cement. The reason why the Pennant Sandstone of the South Wales Coalfield is very strong is due to its sand grains being <;emented by pressure solution. Note also the difference in the UCS of Palaeozoic Slate when tested normal and parallel to the cleavage. Granites can be the strongest of all rocks but they also have the widest range due to the variety of rocks which come under this name. Those with a high quartz content, close interlocking grains and are well crystalline are the strongest. It should be noted that these measurements are for unweathered samples - the strength of weathered rock is greatly reduced. Note also the absence of basic igneous rocks from this table and this is due to the susceptibility of ferro-magnesian minerals to break down to clays when weathered with the resulting loss of strength. If load-bearing is the main use for the rock this test prOVides the reqUired information but those rocks which give the best results here may not be the best for other purposes. b) Water Absorption and Shrinkage This is of greatest Significance if the aggregate is to be used in concrete. An aggregate with a high water absorption due to, for example. porosity, will abstract the water from the cement and cause the whole concrete mass to shrink with resultant fractures and loss of strength. Rocks with a clay mineral content, particularly altered basic igneous rocks are particularly bad in this respect since clay minerals such as montmorHlonite have a great capacity to absorb water and swell. plaCing internal stresses on the concrete with resultant fracturing and ultimate weakness. Grading This is the distribution of particle size and the c) sizes sold are achieved by screening in the quarry which can never be totally effective. Some undersized partides could well be present and the main concern is in regard to fines (less than 7SJ.tm) which coUld include a day mineral faction. However. if the fines are not day they need not be deleterious but are likely to cause high water demand in concrete. Tests on the final concrete product are used to assess strength. It is then the obligation of the supplier to maintain consistency of particle size distribution percentages in the aggregate so that consistency of quality of the concrete is maintained. The following tests relate primarily to road bUilding particularly the road surface which has to withstand the effects of traffic and weathering. Aggregate Crushing Value (ACV) measures the red) sistance of the aggregate to a continuous load. Note thatit is the fragmental aggregate that is tested here not a sample of rock as in the Unconfined Compression test. In the ACV test the fragments of the aggregate will rub against each other producing fines and it is the percentage of nne$ produced which this test measures. 119 60 60 t::::l Horntets 50 - Porphyry ,., 50 g = - Basal! c:::J Hornte~s - 50 Grantte ·60 Porphyry 50 c::J ~asan _Granite .'c:iJ '" 540 '"'" ~ 40 ~ " 30 er W ~ 20' '"" OhJ~~~~~~~~~ a la) Aggregat"crushillg value 60 50 o ~B""1.u..OIlU12C1l1w4"'SA,Ua 201.0- Z'-22..l..4-'ZLS2-'-6-'3'--0 10 !214 )618202224,262830 c::'J Quartzlte GfllS(One (b) Agg"'gale cruShing value la) (b) Aggrogale Impact value 60 60 50 50 Aggregale impact value 60 c:::J Quartlite - c::J Glitslone 50 Umeslone O~~~~UU~~ua4U B 1012141,616202224262830 Aggregate crusrung value . e 10 12141618202224262830 Agglegale Cfust'!"rng value (d) Figure 5. Aggregate crII$hing value (ACV) of British Roadstone. Data from Rood Research Rood Note 24. e) Aggregate Impact Value (AIV) This, test simulates the continuous pounding from traffic that an aggregate will have to Withstand. Whereas for the ACV a continuous load is applied. this test employs a standard hammer dropped from a standard height onto the specimen for a prescribed number of times arid the amount of fines produced measured. Aggregate Abrasion Value (AA V) This simulates the actiqn of pneumatic tyres impregnated with grit on the wear· ing course of a road~ The loss of weight of a fixed sample of aggregate is measured after it has been abraded by a rotating lap fed by sand for a prescribed time. f) Graphs of the results of these tests on British roadstqnes are shown in figs. 5, 6 and 7. The relationship between ACVand UCS is not always dear. Note that Carboniferous Limestone has a higherUCSthan most sandstones but is out performed by qIJartzite and gritstones in the ACV and .AtV and performs worse thanbasaJts in both tests. Homfels perforr:ns the best of an rQcks for its ACVAIV and AAV which is not surprising since it isa very dQse textured siliceous rock with interlocking grains. The hardness of quartzite is dearly manifest .in its excellent performance in the AAV test. Limestones overall do notperforrn well in all these tests in relation to othe.r materials and )let they are widely used as the wearing coorse.on cl road. Perhaps the next text will help explain the reasons for this. g) Polishe.d Stone Value (PSV) This mejlsures the ability of aggregat~sto lose their roughness on the Wearing surface of a road after a period of use by traffic and develop a polish with the resultant dangers. All other tests wilt measure thedurabiJity of a. road surface and have economic and inconvenience implications but this test is used to ensure that inappropriate Agglegate impacl value (c) (d) Aggregale impacl value figure 6. Aggregate impoct volue (AIV) of Britisb Roodstonses. Data (ro,pRoadResearch Rood Note 24. 70 70 = 60 HOrnlels "'Porpnyry 60 c:J8asalt -G(ar~ute ~ 50 ~ ~ 40 ., g> ~ £ 30 20 10 I. 10 O~0~2~4~6~8~10~1~2~1~4~1~6~I8~20:-0~~~~~~~~~~ (a) Aggregate abraSion value (b) 70 70 60 60 c:::::I QuartZite - Grttstone = Limestone 20 10 Aggregate abras"'" value (C) Aggregate <>btaslon value (d) figure 7. Aggregate abrasioQ value .(MV) 0.( British Roodstones. Data from RotJdReseal'ch Rood Note 24. Figures 5, 6 and 7 from Prentice 1990, figures 3.2 page 74, 3.3 page 75 and 3.5 page 77 respectively. © 1990}. £ Prentice. .Reproduced with'kind permission ofKluwer Academic Publishers. Teaching Earth Sciences: vol. 23, pt. 3 (1998) 120 5 (Slag) (Calcined bauxite) Artificial group o ~ C'---'---"--_~.o..:L.I---.J'--J1 1 ~ .. r ~ -,---,---,17Z<!<"<'<'----'---L--.l1--J1 a. ~[ '""' :r <Il Cl E (; Qj D E " Flint group Granite group '~r'--'-'-'--'---L_L-..l.-.J~~' 1!LL:d>~:!CL:~---,1 ~[ 15 Basal! group (Calcined flint) (Normal flint) Gritslone group Homlels group (Normal limestones) 10 5 (Gritty limestones) 0 limestone group Tf Porphyry group 05fL_~I~t~~~n2~~2~V~+~~~*~?~2~3~~I~1~I 25 30 3540 45 50 55 60 65 brake. It could be just like braking on a surface ofsmallbaUbearings. Hence all these tests have to be applied and as is the case with much in economic geology only a few rocks pass all the tests - these can command a higher price in the market place. 70 75 .Quartzite group h) Flakiness This is a measure of the shape of the aggregate particles and because of the nature of rock formation most rocks have an inhomogenous character that when broken they form flatter and elongate fragments rather than cuboidal. Quantification of this feature is undertaken by measuring the three dimensions of at least 200 pieces of crushed rock and determining length ratios. This laborious process is necessary because these fragments will always align themselves in concrete and the strength ofthe concrete will reflect the strength of aggregate in its weakest orientation. Note the difference in the UCS of slate parallel and perpendicular to the cleavage (FigA). i) Resistance to Weathering Weathered rock will make an inferior aggregate to unweathered and hence it is important during quarrying that weathered material is not incorporated with the unweathered. Natural weathering processes will affect rock aggregate when on a road or in a structure and hence it is important to establish the length of time it is likely to take before the pristine rock becomes weaker through weathering. For example, top dreSSing on a road should be such that it will not deteriorate through weathering during the desired life of that section or road. Tests to simUlate freeze thaw conditions and the effects of moisture need to be undertaken. Polished stone value Distribution of polishcd stone valucs in different groups of rock Figure 8. Distribution of Polished Stone Values (PSV) of different groups of rock. From Prentice 1990 (after Hartleyf970) figure 3.6 page 79. © J. E. Prentice. Reproduced with kind permission of K'uwer Academic Publishers. material is not used as a wearing course since it could result in loss of life. . Fig.S shows the PSV performance of a range of British Rocks. In Britain a PSV of 65 is regarded as the lower limit for a skidresistant surface and these rocks should be used where the road conditions present a particular hazard. The graph (Fig.S) shows that rocks of this quality are far from common and with the exception of the artificial group it is some gritty limestones and gritstones which are the best. This answers the question raised above and despite their weaker nature hi respect of ACV, AIV and AAV the factor of safety and high PSV is paramount. Gritstones and Gritty Limestones owe their high PSV to the fact that each of the main constituents' abrades at a different rate. The calcite in a gritty limestone will abrade easier than the quartz grains leaving them standing proud. A similar situation occurs with gritstones, particularly some greywackes (though n.ot all greywackes) with a high porosity and more clay and lithic fragments than quartz. It would be quite easy to assume that a high PSV would make a rock ideal for a wearing surface on a road but this cannot be use,din isolation. A rock with a high PSVmay fragment very quickly and result in a road surface which is covered in loose grit with its attendant dangers when vehicles slow down and Teaching Earth Sciences: vol. 23, pt. 3 (1998) It can be seen from the above that comprehensive tests have to be made before a rock can be declared a suitable material for aggregates and it is rare to find one rock which satisfies all criteria and hence in any conStruction a variety of aggregates are reqUired for different purposes. When you visit quarries, whether working or disused,it should always be remembered that those excavations were made because somebody needed that rock and was prepared to pay to extract it. They were not excavated to: provide debris' for fossil collectors or to display other geological features. In a quarry always ask yourself the question,"What is special about this rock in this locality?" and on the oasis of the points listed above try to consider appropriate uses. Also consider why the quarry (if it is abandoned) came to the end of its life - the answers may be geological or they may be commercial. 4. Fine aggregate In construction usage this is material which is below 5mm diameter. To all intents and purposes it is sand though sedimentologists regard 2mm as the upper size limit for sand and to them fine aggregate would have to include some fine gravel. It need not be natural sand since some fine aggr~gate is produced by crushing coarser material and its composition can be minerals other than quartz or rock fragments. This material is Widespread but like coarse aggregates it has to be established that the quality is right for the required usage and that it is in the right place. Like crushed rock it needsto be as close to its point of usage as possible and if it is too distant it can render the deposit uncommercial. An obvious example would be all the sand in the Sahara which would be too expensive to transport to Britain. A less obvious case is>the sand produced as a result of china clay extraction in Cornwall 121 which is many times more than the needs. of the local area but cannot be economically transported to other parts of the country. a} Uses of fine aggregate In most construction uses fine aggregate is a filler .. In concrete, (pr example, It fills in the voids that would be/eft by the coarse aggregate thus reducing the requirement of the bindil1g agent, cement, which is more expensive and weaker. Thus, fine aggregate contributes to the strength of the concrete. i) Con~retjng Sand is a major constituent of mass concrete and can also be used in the 'unbound' secti.on of road ways. In both these cases it is used With coarse aggregate. It is also used in concrete products such as drainage pipes. concrete pavers, kerb stones etc. (B5882). ii) Building Sand when mixed with cement produces cement screed for floors and wallreridering; another signifi.., cant use is in brick mortars (BS 1200). ill} Asphalt Sand is produced when mixed withbituminousproducts and is used in the bound section of roadways as tarmacadam (B5594). In unbound form it is used as a filler in trenches for main services. For each of these uses different 9uality parameters are required and the tests have to be carried out according to British Standards as has the product to meet the quality parameters. b. Specification and Testing i) Grain Size Analysis This is carried out by sieving samples of the sand and recording the particle size distribution... This procedure has to be undertaken with care to avoid misinterpretation. due to errors in the procedure. For exampie. a concrete sandshoutdhave a Wide range of partj~le distribl.ltion sizes (!.nd beaogularin order to produce a dense wel~ packed interlocking structure to give the concrete strength. A uniform size of spherical grains would cause sliding of partic1esal'ld leave a large volume of void which would need to befilfed in with cement. If notfilled with cement the pores couldeaslJy .become saturated with water· or remain as alrfllledcavities. This would be detrimental under freeze-thaw conditions. AG{l!~EGATES FOR MORTAR lao ,-'-_ _ _ _ _ _ _ _ _-:;:_---:\,:.:;;1&=mm~..;.2;;;;.)..:..6m"_I!\'_::::Sr·O ..1!\ Mortar sand has limits d~fined as showniri the accompanying graph (Fig.9) ii} Sf.!lk Density This is an indirect measure of pary:ic;:le packing. The closer thepartides·are packed the greater will be the denSity of the sand. A sand .with many ~qidswouldhav.e a lower dry density. The percentage voids. can be: cakulated by comparing the bulk denSity of the sand with the density of the mineral which if quartz is 2.635 grams/cc. If ltitre.of dry quartz sand weighs 1.527kg the % voids is (1- 1.527 IX 2.635 100 =42%. iii}Grain Shape Sphericityand roundness are the main factors to beas~essed, both of which are undertaken by a qualitative visual approach using a binocular microscope and comparing the grains with printed charts. Well rounded grains increase the workability of mortar sands and are therefore reqUired for a sand to be used in wall rendering whereas angular graiITs, as stated above, are best for concrete. Thetwo types are not interchangeable in their usage. iv) Mineralogy .lnBritain, because of the recent gladations with the attendantm'elt water flows the softer· minerals have been removed leaving behind quartzose sands. In troplcal latitudes where chemical weathering of rocks dominates with laterization fine aggregates of aquartzose nature are difficult to find. A good flne aggregate. should be dOlilinantlyquartz or quartzose rock though this cannot be stated categorically as constituting a suitable fine aggregate. Some strainedquaru andchert have been shownto have a defeterious reaction with the cement (Alkali Sni~ Reaction) causing stresses and hence fractures in the concrete. Hence it is Important to determine the nature ohhe silica. Soft and friable minerals can cause weaknesses in the product and elongate particles can cause somelami~ationjn the concrete thus affectingitsstreilgth .• TI-le commonestdefeterious minerals are days.• coals and carbon(!,tes. The .smectite days such as Montmorilfonite cause shrinkage due totheirllbility to absorb moisture and can cause concrete to crack. . For mortar sand a little day Can give a smoother finish and if it is. not a smectite there may not be shrinkage problems .•. However,· it .is the retardation of adhesion with cement or asphalt that causes problems when day partidescoat quartzosegrains: Coal, Iign;teand peat are a problem for concrete roof tiles since they allow leakage and theirpresencein a sand f113yrend.er it unsuitable for this purpose since they ar~not.readilyremoved. Problems occur with carbonate minerals if they are mixed With quartz due to their dIfferent absorptioll ofmoisture at:ld resulting differential shrinkage. lithe fine aggregate is. entirely carbonate, as are sands in mal"lY tropical areas. the Same problems do not arise. 90 In Britain flne aggregate is won from:- marine sands Which are often. rounded grains and too fine (incorp9rated.sneflsare a problem due to the voids they callse);glacial sands where sorting is imperfect andsome poorly cons()ti!JatedTertiary and Cretaceous Sandstones . such as the l.eighton Buzzard Sands (lower Greensand). River sands and gravelspravide a source of coarse and .fjnea~regate together anddmbe used as a combined mix or can be sorted into the two main factions. 80 70 .[ 6-g cE' ',sa ~ 40 :; 3~ 20 lD oL_ _...i.-_---".....,;:;:=---"---.L-------15 ISO 3~O 600 s. Cement raw materials P>ttlcl. Siu I_I Figure 9. Revised grading limits fo,. general purpose brick mortars (851200. 1984). Teaching Earth Sciences: vol. 23, pt. 3 (1998) Portland Cement, so named because when compact it reSembles Portland Stone, fsthe result of flring and subsequentlY grinding a carefully blended mix of rocks and/or minerals. 122 (Tricalcium silicate ) Ca 3 5105 Figure lOa. Ternary diagram for the system CaO-AI1 0 3-SiO,. showing tlie are.a of Ordinary Portland Cement composition. Main Constituents of Cement Clinker Chelllic41 Name Tricalcium·silicate Dicalcium silicate Tricalcium aluminate Calcium aluminoferrite Empirical Formula Ca)SiOS Ca2Si04 Ca)A1 2 0 6 2ca2AlFeoS _ Oxide Formula )CaO.Si0 2 2CaO.Si02 )CaO. A1 203 4cao.Al20). Fe 203 Short Forumula C)S C2 S C)A C4 AF Figure lOb. The main constituents of cement clinker. From Jefferson '978. What is paramount in the soureing of raw materials for the manufacture of Ordinary Portland Cement (OPC) is to get the mix of chemical compounds right. The Romans made an excellent Cement by their mixing burnt lime (CaO) with Pozzolana (Volcanic Ash), sand and water. Naturally occur· ring or artificial materials which react with lime and water to form compounds with cementitious properties are still known as Po:tz.elans .. The process used today was patented by John Aspdin in 1834. According to British Standards (BS 12: 1970), "Portland Cement is manufactured by ultimately mixing together cakareous or other lime·bearing material with, if required, argUlaceous and/or other silica, alumina or iron oxide bearing materials, burning them at clinkering temperature and grinding the resulting clinker so as to produce a cement." Teaching Earth Sciences: vol. 23, pt. 3 (1998) Jefferson (1983) stated that wortd production of cement is in the order of 875 million tonnes, utilising about 1,400 million tonnes (dry basis) of raw materials. The U.K. production is about 14 million tonnes per annum requiring 24 million tonnes of raw material; Modern Cement works have an output of about 4,000 tonnes of cement per day from 6,000 tonnes of raw materials manufactured in a continuous process within a closed system. The raw materials must be thoroughly proven to guarantee a supply of material of consistent quality, free from impurities because in a modern closed plant they cannot escape, resulting in an accumulation of harmful substances. As shown in Fig. 10 Portland Cement is a mixture ofCakium Silicates and Caleium Aluminates each of which brings its 123 partICular qualities to the cement in regard to strength and . rate· of ·setting. These compounds are entirely de~endent .upon thechem1calcomposjtion of the raw material and ideally . in themanut'actur'ing process the elements present in the raw rnate!i;dare ·transformed.bychemi~al reactions from one set ofcotnpounds to another. The only loss to the system is CO2 and moisture. High·gr«kmaterl~s Hence oin the. identification of cement raw materials it is nec.essary to get the chemistry right. It does not matter what is used providing the compounds aICe present in the right mix. The requirements are for large quantities· of a uniform source of calcium. sltita.aluminium. andiron. Since consistency and uniformity are required it is essential to know the variation in a deposit so that blending can take place ;lndthis highly skilled task is.thejob of the cement chemist. In. addition the minor constituents in the rocks must be known particularly if they are deleterious and of theseMgO and Sare so harmful that they are limited by national standards: Mg04% max. and Sulphur3%max. according to BS 12: 1970. Some magnesia will combine to form silicates but some can remain asperidase which hydrates. slowly and expansively causing disrup~ion and possiMe failure of the hardened concrete.. Some sulphur is necessary to prevent "flash setting" (almost immediate hard· eningwhich can result;n a solid mass before it can be worked) and hence iithe raw material isdefident in sulphur, gypsum is added. However, too much sulphur 'Can cause low strength and high expansion of concrete. High alkali levels (~O and Na 0) in the cement can cause· alkali-silica reactions .If used with reactive aggregates. Manganese, phosphorus, chlorides and·fluorides can also cause problems in all but the smaUest quantities. Some examples of identification and clever blending of raw materials: The. Bahamas, where there is a plentiful supply of coral limestone, imports Bauxite .from Jamaica, Silica Sand from·Florida.lron Ores from N. Can!lda and Gypsum from Nova Scotia. In Perth W. Australia coastal dUne sand which contains. Ca and Si02 has added to it a low grade ferruginous bauxite (AI and Fe) The resultin both cases is OPC which meets national standards. Teaching Earth Sciences: vol. 23, pt. 3 (1998) Low· grad.· ""'Ierlal• Plloc.ne 40-j-----l Eoctn. korlhflut (x.nt) WovidhO.m (Eun} NOrmClt1 (CQmbridonh~) 'Hotbor-o.u(}h (Kent) StWrch-Om (Svnu) Wc-stbury , {Witt-shit~} Hurnb4t (Yorktwn) ()dord <Odon:fshirt) AbU1hQW (Glol"l\Oqlao) Rho-ost (Glornorq-o.n) Hop< (D<rby$hn) C'ouldon, (OubYShirt.} E;OokSIQWl'l, (Norlhvn· tr«tOM) Dunbar (East L9thiOh) CIiU1*r04! {la.r.caSlwlif} Wc.ardol« {Ou"hom} It is possible for a single raw material to have a composition suitable for Portland Cement manufacture such as some ofthe Lower Chalk of the Chiltern Hills and where this occurs it is referred to as a one component mix. The majorityofcement works;n Britain use a two component mix. In the South this is mainly based on the Cha.lk as the primary component of the mix with days from the Jurassicto Tertiary as the secondary component.· In the north.Carbonjferous Limestone provides the main component and CarbQniferous Shales the other. (Fig. I I). A useful c1assexerdse could. be to try to identify suitable materials· for. Cement Manufacture in different locations. Remember it is the chemistry that has to be right and little else matters. A blend of Caldum Silica Aluminium and Iron must be achieved. Pupil~ could even set about trying to identify why dolomitlsed limestones are IiOt suitable, Also why was .it important to site a ceme.nt works near a coalfieM- Answer is energy to drive the system. In Britain4mtof Coal (orOH and Gas equivaleJ1t) is reqUired annuafly. Thfsis less important now with there being more oil and .gas fired plants in the country. More plants are going on to a dry system of productionWher'eas in the past wet or semi-wet processeswefe used. Why~ Answer is energy costs -It is expensive to drive off water ·added during manufacture'so don't add it. Cam.ntwOri<. Ctmcnt Works Ptyrmtock· fD<von) Figure 11. Horl%ol1S ex,plo/ted by selected U(fited Kingdom cement works. Ftom Jefferson 1978. 6. Brick Clays Introduction The role of bricks .in. constructionhas·.chaflged ~ramatically over the past 30 years with an attendantr~~uctionin the number of brickworks in Britain. Aericl«Oe¥elopment AssociationslJrvey Iists 800 separate bric.kworks in the year 1966 producing facing· and/or common bricks; at the end of 1992 there were 157 brickworks in. Britain of 'whichapproximatelyl30 were day, 22 concrete and the remainder calcium silicate; today the tQta~ numberhasfaUefl·toaboutSO, A major factor which contributed .to the decline in the production of bricks was the advent of the concrete block for the load bearing structure in.b~i1djngs. This resulted inthealmost total demise of the production of common bricks which were previously used for this purpose. 724 Over the thousands of years that clays, muds and shales have been transformed into bricks the over-riding important criterion for a brick-making material was its strength to do the job Brick-making is recorded in the Bible in required of it. Genesis Chapter II in the context of the building of the Tower of Babel "And they said to one another, Go to and let us make bricks, and bum them thoroughly." This gives a remarkable insight into the skills of these people because they knew that the clay had to be burned thoroughly before it would make a strong brick ~ at least strong enough to build a tower that was to reach to the Heavens! Kaolinite SI-O AIOOH AI Montmorilfonite That may have been adequate for those people but the sop histicated.consumer of the late 20th Century requires a brick to be aesthetically pleasing as well as strong and durable. Since bricks are used today primarily as a cladding on walls the choice of brick used is largely determined by the current fashion of architects. A successful brick-producer will have a wide.range of products with a variety of colours and surface textures to satisfy the range of market demand. Hence, .modern bricks should have a constant size, shape and colour to meet the demands of the architects and planners in any single project - of course colour will vary from project to project because each architect has a pre-conceived idea of what will look right. In addition, since the cladding will be exposed to wind and rain the bricks should have a low percentage water absorption and good frost resistance as well as a high compressive strength. The skill of the geologist in the brick industry is to identify and evaluate a deposit that will produce marketable bricks and when in production to ensure that a feed of constant quality leaves. the clay pit for the brickworks. It is on this basis that the factory is designed to manufacture bricks. Si-O AI·O'{)H ~ _ _ _ M9'Fe SI-O AI IIlite Chlorite AI The Nature of Brick Clay Each naturally occurring clay deposit can be considered as an individual blend of chemically different (or in some cases chemically Similar) minerals assembled in a characteristic pattern of particle sizes. It conJ;ains clay minerals from one or more of the cI<tY mineral groups, mixed by its unique geological history with a variety of other minerals (mainly quartz) in the form of unweathered or partly weathered rock fragments. Although the mineralogy may seen initially to be simple - day, quartz and about 10 other constituents it is the variety of these.changeable associations of minerals that controls many aspects of the brick-making process and the character of the finished brick product. Clay minerals are very numerous and their identification has been made possible by X-Ray diffractometry (XRD) which identifies their different crystal lattice structures and the Scanning Electron Microscope (SEM) which makes .it possible to observe their individual structural morphologies. In brickmaking raw-materials clays of the Kaolinite, IIlite, Montmorillonite (Smectite) and Chlorite groups are of dominant importance and Simplified structures of these are shown in Fig. 12. It is best to consider the composition of mud rocks from the standpOint of which minerals are useful or essential to the production of a good brick and those minerals Which cause problems. A. Useful minerals I. Kaolinite AI 2Si10s(OH)4' This may be ordered Kaolinite TeaChing Earth Sciences: vol. 23, pt. 3 (1998) The arrows show the penetration of the Crystal Lattice by other flletal ions. The various metal ions have different sizes. The effect is a bit like building a wall with Metric and Imperial bricks - the structure is weakened, Such clays are more easily broken .down into small particles and the. material is more plastic and stronger because of its smaller particle size. Figure 12. Structure of Clay minerals. where the individual plates are regularly stacked or disordered Kaolinite where there is distortion of the stack. Most Kaolinite in China Clay deposits is ordered whereas the Kaolinite which has been transported to be incorporated in sedimentary rocks is disordered. On firing in a kiln Kaolinite gives rise to Mullite (AI~Si20'3} which gives the strength and durability to the briCk. 2. lIIite Ky AI,2(Si1_y) 0lo(OH)2' During blending of the crushed rock and miXing with water lllite helps develop suitable degrees of plasticity so that extrusions or mOUldings can be formed. Since it contributes to a denser packing structure of the unfired day body it promotes a dense impermeable product and hence a better quality brick. It also acts as a fluxing agent, helping the reactions in the kiln and hence its presence may lead to a saving of energy. 3. Muscovite K AI 3Si 30,o(OH)2 when present can act as a f1uxing agent. 4. Quartz Si02, A rock with only clay minerals present and a few accessories is difficult to work in the production process and is often referred to in the industry as. "too fatty". The presence of quartz reduces the plasticity of a 725 day unsuitable forbf'ickmakingbut it does testthe skills of clay and lessens the. shrinkage of the brick during drying . the engineers and plant designers. and firing... Without quartz there would beex.cessive development of Mullite and glass during firing which would result lna weak. product. Quartz sand may need to be 4. decompose Carbo.t1.,a.te.s. onheatingto~O°C C.aCO •. )' M&.C. q.~,c.a.•..M .••• giving &(C . . . 0. 3Ott~arboA ).'.....~ '. F.e. C.O .• ,...3.•. .•• The •. s. e Diox-'added to aclayifthe original level!) of quartz are too Jow. The .balance of quartz and clay must be right since,too ~=~::cti)a:ig~ehind a reactive oxide.> For example much quartz on the other hand can affect the colour of the fired product or reduce its strength. Coarse particlesofthisreactive oxi.de¥ihicl1survive the firing cantater react. with moisture in thea~m9Sphl:lreand 5. Iron Oxides. These give colour to the brick and if a clay is deficient in them they may need to be added during as it changes from9uickUme(CaO)t~ slaked lime (C\l(OH)?, it produces an expansion which can causesln\lUpiecesot blending to produce a. marketable product. ·If fired under the face· of bricks to .f1y. off.. Thisiskngwnasfime p.opping oxJdlsingconditions bricks which eangeneraUy be termed and can cause in time disintegration of thebrtck. red are formed but under reducing conditions and high temperature firing (which not an days are capable of taking without excess vitriflcation) they produce blue bricks. A The loss of C02during firing may give rise to .a higher porosity product than expected•. The resu/tis.a. prodt;lct top quality engineering brick. the Staffordshire Blue,prownich is .not as strong. absorbs more moistul'eand 'It(iII ducedfrom the Etruria Marl, is fired in part under redUcing conditions. therefore disintegrate under freete-thaw .cofl~itiOns; Figure 14 iflustrates this point well since the Keuper. Mad has a much higher CaCoJcorrtent(approx. 11 %) than does the 6. RutHe Ti0 2 If present can give a purple colouration to the end product. Should that colour be required by anarchiWealdClay. tect and the rock is deficient in it, artificial Ti02 can be added during blending. Whilst iA general it is true to state that high levels of Carbonate in a raw material may·render it unsuitable for brick manufact.urethisisnotuniversallythe case~. The B. Problem minerals Upper EtruriaMarl.ofNorthStaffordshire has large particlJ;!sizecaldum 9rbonate andh:e.cause of thisit iiS not used I. MontmorHlonite (Smectite) AI2 SiPIO (OH)2' The pure to produce bricks. On the other hand the Gault Clay of material is not found in naturJ;! liecau~e some of the silicon SE England ca~haveJ 1%C\lC03 butbeeauset.Oe,partide has been replaced by Aluminium and some Aluminium. by size of the. carbqnate. is so small, it does notrea~ttothe Manganese and fron. These .substitutions leave the layers same degree and will produce a marketahleiJricK. . It is negativefycharged and so metal ions With positive charges technically possible to reduce the grain size of the~rbon are attracted tothesunace·ofthe clay particles and to the at.e in the Upper EtruriaMarl,as rsdone bYisome tile spaces between the layers~ The result is a complex and manufacturers, or even beneficate themateri;,dthrou8h disordered structure of smalt p\lrticlesizeand high plasticremoval of the calcite nodules, but the costs are prohibiity. An interesting characteristic of MontmoritJonite is its tive. ability to absorb water between the silicate sheets with simultaneous uni-directionallntracrystalline swelling per- 5. Iron Sulphide FeS. This ca.n be present.~s. Pyrite or pendicular to the sheets.. Such days are difficult to work Marcasite. This. give~ rise to the 'deveiPP01eitt of black and from a brickmakingperspective their presence in any cO;res in the firedpl'oduc;:t (thoughsoM~~I;rFhit:eets n9W quantity would. render the deposit unsuitable for tend to favour smallblac.k spots)~\lnde"orescencevyhen brickmaking. The days would swell .exceSSively during exposed to dampconditioAs. There is also the problem of bfendingand mixing and would shrink withattendantdissulphur pollution during manufacture: tortion d\;n~ing drying with the result that a mis-shaped product wOllld result, not to mention the chaos caused in the kiln by theinstabllity of stacked unfired(orgreen) C. Other tnQterials bricks. which would •probably.·. topple. A c011apsedor toppled stack in a kiln would block the movement of the I. CarbaceousContent: This can sometimes aid firing ofthe bricks through the kiln or rip out the insulation material on product and hence reduced the energy required to prothe side and it would take a week to put right~· stop firing ducethe bricks. A dassic(lase ~. energyeffjcieAcyis with and cooling (3 days), removal ( J day) re-stacking and firing the FlettonBric.ks llearPeterborqugb,Therormerclay to the correct ~emperature· (2-3 days). The cost of gas pitsinthe Lower OxfordClaywere dev:efopeq\lslandfill at9ne . tc> re-fire a kiln to th.e correct temperature is .about sites. and these. produced methane'frol1l~e' waste: .Tflis £40,090. That is expensivel However, Montmorillonite methane was piped into the bricKworksvvnE![eitvvas used has its uses since cat-litter is produced from it as are to start the firing of the bricks ..... Becli\useo( ij,e high drilling muds for the oil and gas i~dustry. organic (Carbonaceous) . contentofthe,L()VVerPxford Clay the bricks themselves aidedintheirownseff..uring when ignition temperature ofthecarbon~ceous material 2.. Chlorite.(Mg,Fe). Al (AfSi 3) 010 (OH)s' This may.swell, was reached. though not as extremely as montmorillonitet to cause cracking of the product body. High Chlorite rocks are not suitable for brickmaking. DIstribution and Relative Importance of 3. Common Salts KCf and NaCl. These are vigorous fluxes and· will. be removed by dissolving·· into the glassy melt durIng firing. Unless destroyed by firing both wiHcause efflorescence (a WRite fllm).on the surface· of·the brick when it is weathered. Theirpresence doesnot render a Teaching Earth Sciences: vol. 23, pt. 3 (1998) Brici<making .clay resources. in Britain. The accompanying diagram (Fig.J 3) provides an indication of the relative importance of brlckmakingclays assQciated with different geological periods in Britain. This diagram is a few 126 QUATERNARY Brickearth [ Clay with flints Till, glacial clay, alluvium and other TERTIARY ! London Clay, Reading Beds etc. GaUlt Clay CRETACEOUS Weald Clav Hastings Beds Lias clays 'Keuper Marl' TRIASSIC Etruria and Ruabon Mads ~imE1~i:::!liii~i:£~a' Measures and Millstone Grit Culm o 5 DEVONIAN Devonian marls SILURIAN Llandovery slates ORDOVICIAN Ordovician slates 10 15 20 25 Percent extraction 30 35 40 45 50 Figure 13. Relative importance of U.K. geological formations in brick pipe and tile manufacture. years old and recently there have been minor changes particularly in regard to the Jurassic where production from the Lower Oxford Clay has decreased. Most of the pre-Carboniferous rocks have been compressed to such an extent as to render them unsuitable for brickmaking. In the Carboniferous the Coal Measure Shales have been used .extensively to manufacture bricks. pipes and tiles. However. thick Coal Measure Shales capable of producing a consistent high quality brick are not common. One such is the Accrington Mudstone. a formation which today has to be sought under increasing thickness of overburden. The fireclays (seatearths) found below the coal seams are dominantly composed of kaolinite and their high al,umina content makes them valuable both for the production of white to buff coloured facing bri~s (whi<;h can command top prices because of their fashicmabJe demand) aAd for the production of sanitaryware and (19W grade) refractory products. The Upper Carboniferous Etruria. Marl of N. Staffordshire is arguably the best brickmaking day.in the country. The Mercia Mudstone Group of the Triassic is stillreferred to as the 'Keuper Marl' in the Brick Industry and is an important producer in the English Midlands. The L9wer Oxford Clay is of great importance to the brick industry but although this deposit is widespread. extraction for brick-making is mainly confined to the counties of Northampton. Buckinghamshire and Bedfordshire where it is found to be remarkably uniform in thickness and properties. The Weald Clay accounts for most of the production in South East England and it is a very important clay fonhe manufacture of Engineering and Facing Bricks. It produces strong bricks with a high firing temperature and a close structure (Fig 14). The Gault Clay produces bricks ranging in colour from creamy white, through pink to light red with some scarce bands producing a buff.firing brick, The variation in colour is due Teaching Eorth Sciences: vol, 23, pt, 3 (1998) essentially to the lime content. the highest lime percentage (CaO = 18 - 26%) producing white bricks and the lowest (CaO < I%) producing red. The white Gault bricks have low bulk densities due to their unusually high porosities. Of the recent deposits particular note shOUld be .made of the "Brick Earth", This deposit 9f generally sandy-coloured loam, normally only 2 metres thick, occurs principally in North Kent and South Essex, The Si«ingbourne area was the centre of the thriving North Kent brickearth industry of Victoria times when barges of the City of London's 'dust-bin' waste (containing a high proportion of semi-burned coal and putrescibles (both with good heat value) were taken down the Thames by sailing barge. After being screened it was mixed with Brickearth and used to fire primitive kilns to produce the yellow 'London Stocks' (called stocks because they were hand-thrown ana wooden bench called a 'stock'). These were then sbipped back to London on the same barges that brought the dust-bin rubbish down. These bricks featured dominantly as the main building brick used for construction during the inner London building-boom of the Victorian Era: a very early example of profitable waste-recycling! Today, virtually all the Brickearth deposits in this area have been exhausted or sterilised by building development. It should be noted that there are a number of clay horizons which have not been exploited for the manufacture of bricks. The Jurassic Fuller's Earth is a Montmorillonite Clay and he.nce is unsuitable for brick manufacture. though it is a valuable commodity in its own right. The relative uniform lithology of the London Clay is accompanied by an almost consistent clay mineralogy. montmorillonite. and illite being the major components. The London Clay has never been greatly favoured as a brick-making clay largely because it is highly plastic. with an unusual capacity for absorbing water. A high drying shrinkage results and can cause excessive damage during the drying stage of brick production. 127 Figure 14. Scqnning Electron Micrograj>hs ofbricks j>roduced (ramal Keuj>erN!qrland b) Weafd Clay fired at I fOO"C. Note the larger and greater number of pore spaces in the Keuper Mori Brick. 7. Overview One over-riding factor that should be appreciated from the preceding sections is the role. of quality control. and the meeting of national standards. 0 return to a .comment m~d.e in the introduction the term Common Clay and Shale IS totally misleading since. high qualit.y. brick days are not th~t common. Admittedly there are millions of tonnes of rock In Britain that could make bricks bUt. they will not meet the quality criteria required or. more precisely, the final fired colour demanded by the architects. J There are masses of limestones in Britain but dolomitization would render them unsl,Iitable for cement manufacture though they may make good aggregates. Conversely the Chalk is a suitable material for cemet;\tbut in Engl;1od it lacks the strength to be used as an aggregate•. though in Northern Ireland baking by Tertiary Volcanicity has made much of the Chalk there a hard strong rock of aggregate quality. Sands are Widespread but not all have interchangeable end usage and furthermore they may not be in the :ight place. For example large quantities of sand are produced tnCornwall as a result of China Clay extraction, well in excess of the d.emands of the local area. The surplus has to be put to waste since the transport costs to distribute it to other parts of the country are prohibitive. Appropriate examples of the importance of quality control for construction rawm;lterialsaremany and perhaps next time, as teachers. you take iparty of budding geologists to a quarry ask yourselves and them a few questions such as:i) Why is this quarry here? You can be sure t~at it was not excavated to provide an exposure of a partIcular feature for generations of .students to observe. ii) What was the end use of the raw material? Obviously you cannot undertake full· tests in the field but a few simple ones may help. On a recent .1 st. year UniVet'~ity field course toPal'k Hall Quarries neat' St()ke~on~Trent where the Sherwood Conglomerate (forlllerlythe Bunter Pebble Beds) are pverlain by Sherwood Sandstof\e (formerly the Bunter Sandstone) I posed the follOWing questions (amongst others) to the students: a) which of the rocks was the Teaching forth Sciences: vol. 23, pt. 3 (7998) commercially valuable material?· Answer:- The conglomerate because of the durable nature of the dasts. b) Why was the sandstone dumped in the quarry? • Answer it is not strong enough due to itS weak ,ce~ent, w~1I sorted n~ture and rounded grains cQvered With Iron OXide. As a Simple test I built a small pile of fist sized samples of sandstone and asked a student to stand on it. The result was immediate collapse and disintegration into a pile of sand. The pOint about strength Was made. Hi) If the quarry is disused ask why operations ceased. There could be many ansWers such as termination of the. commercial rock at the limit of. the quarry by a geological feature su~h as a. fault; too much overburden and hence it became too expensive to extract; drop in demand fonne raw material; limit of planning consent and many others. iv) Why are the quarry sides the shape they are? The answer to that is proVided in Mr. Steve Beauchamp's paper to the conference - The Rocks come tumbling down. v) Can you suggest an after use for this quarry? If you can. try to establish What geological factors have to be evaluated before that be put. into effect. .If, for example, the quat'ryis to be.developed intoa.'eisu:e facility with ,:,:ater. one of the first aspects to jnv~tlgate IS the permeability of the rock. Whatever theose, the safety. o·f people in the. quarry has to be paramount alld students ..could be asked to investigate pc;>ssibre geplogical dangers SUCD as unstable faces and suggest ramediaton; can The possibilities of studies involVing construction raw. materi~ als are vast and it will start to make stadents appre(nate that commercial geology is as rigOrous a taskasp~reacademic geology and certainly of more. benefit to the nanon. References and Suggested Reading Archer A.A., 1972. Sand and Gravel a~ Aggt'egate; Mineral Resources Consultative Committee, Mineral .Dossier NoA. 29pp. HMSO. London. .•. . Beauchamp, S. J. 1998. The rocks come tumbltng down or why do excavations in rock fail? Teaching Earth Sciences, 23(2), 60-70. 728 Hardey, A. 1970. The influence of geologiCal factors on the mechanical properties of road surfacing aggregates (with particular reference to British conditions and practice). Proceedings 21st Symposium Highway Geology, University of Kansas. Jefferson, D.P. 1978. Geology and the Cement Industry. In Knill, J.K. (Ed) Industrial Geology, pp I96-223, OUP. Oxford. Jefferson, D. P. 1983. Determination and proving of cement raw materials. A Prospecting & Evaluation of non-metallic rocks and minerals. Ed. by K. Atkinson and Rick Brassington, Institution of Geologists, pp 189-209. Manning, D.A.C. 1995. Industrial Minerals. Chapman & Hall, 206pp. Prentice, J.E. 1990. Geology of Construction Materials. Chap man & Hall, 202pp. Ridgeway. j.M. 1982. Common Clay and Shale. Mineral Re- To advertise in this journal Telephone Andy Dickinson on 015 1-424-9358 Teaching Earth Sciences: vol. 23, pt. 3 (/998) sources Consultative Committee. Mineral Dossier No.22., 164pp., HMSO London. . Road Research Laboratory 1959. Roadstone data presented in tabular form. Road Note 24. London 9pp. Roberts, D. E. 1998. Elephant Country: the search for Mineral Deposits. Teaching Earth Sciences, 23(1), 19-28. Savery. S. 1991. Aggregates: The need for realism. Quarry Management, January 1991. Smith. M.R. and Coli is L. 1993. Aggregates. Geological Society. Engineering Geology Special Publication No.9. 399pp. David E. Roberts Staffordshire University SMALL ADS E S T A Small Ad rates are ISp per word with a minimum charge of £4. Adverts should be sent with payment.. sta~ng which issues required, to the Advertisin.. , . Officer,6 Rushton Close. Widnes, Cheshire. WAS :2ZF. Cheques payable to Earth Science Teachers' Association. 129 TEACHING THE EVOLUIION OF IHE AIMOSPHERE AI KEY STAGE 4 Alastair Fleming Introduction The Nature of the Evidence As most readers will be aware, the National Curriculum for Science in England and Wales (ScNC) contains a relatively .small Earth Sciences component. Most of this is buried within Attainment Target 3 (Sc3), most of which in turn relates to Chemistry. Sections of Sc3 for Key Stage 3 (I 1-14 year olds) and Key Stage 4 (14..:16 year olds) headed 'Geological Changes' probably account for no more than 10% of Sc3, Other aspects of Earth Sciences occur outside these sections, some in the ()hysics and biology attainment targets, but also within Sc3 itself. Evidence for the evolution of the atmosphere comes from a range of sources. Essentially these are: However there is another Earth Sciences section in Sc3 which should. be regarded as an essential part of science education for 11-16 year olds. 'Changes to the Atmosphere' contains two statements: 'Pupils should be taught • how the atmosphere and oceans evolved to their present composition • how the carbon cycle helps to maintain atmospheric composition' The likely a,im of this section is to provide a sufficient basis for understanding the depate on the effect of human activities on the atmosphere, and possible effects on global climate. If so, it is important that it should be 1:<lught effectively, and it should also retain its place in the coming revision of the Science National Curriculum. . I. The present compositions of: • the Earth's atmosphere and oceans • the atmospheres of other planets • the Sun • gases trapped in meteorites • gases emitted in volcanic activity • rocks on the Earth and other planets 2. The physics and chemistry of these components 3. The structure and biochemistry of various living organisms, past and present. From the chemist's viewpoint, the atmosphere and hydrosphere are essentially molecular in structure (oxygen, nitrogen, water, etc), with free ions (separate ions in solution) in the oceans, while the lithosphere is composed of gIant lattices with both ionic and covalent bonding. The biosphere draws from both to create mixtures of large and small molecules, with free ions, sometimes supported on frameworks of giant lattices such as shells and bone. But essentiaUythe molecular environments and the .giant lattice envl:ronmentsare immiscible with each other, .and hence these separate layers. Within the Earth the various layers .again refled the immiscibility of different types of structure. This needs to be borne in mind as we discuss different possibilities for the origin of the atmosphere. It is surprisingly difficult for teachers to find any discussion in texts readily available in schools about our understanding of the evolution of the atmosphere. Busy teachers in schools do not have the time, or even convenient access to academic ·Iibraries, that is needed to research an unfamiliar topic - they rely. on the texts available in school, supplemented by their own personal libraries. Many such texts make passing references to stories that are at best vastly over-Simplified, and in some cases quite simply inc.orrect. Even using a university library it proved difficult for the authpr to find up-to-date information outside research journals. However several Open University course units are particularly useful for the scope, depth and accuracy of the information given; the new course units forS269, 'Earth and Life', should more than satisfy the needs of teachers for background knowledge, though they are unlikely to be readily accessible to the average secondary . science teacher in a school. AS'planets were formed by accretion.from the primitive solar nebula; hydrogen, helium and .traees. Qfother gase.s would form, primary atmospheres around the new. planets, with composition similar to the Sun. The Qu~rplanets have probably largely retained these primary atmospheres,given their larger masses and low temperatures. The present atmospheres of these planets are very simil"r to .each· other, . but quite different to those of the inner pl.anets. The purpose of this article is to provide science teachers with a summary of the present understanding about the evoIution of the Earth's atmosphere on which they can base their teaching schemes for the topic. ThIS is a topic in which current research js producing rapid advances, and this summary will almost certainly be out of date in one or more respects by the time it appears in print! Hydrogen andheUum molec;:ules are toolignt to be permanently retained by the Earth's gravitational MId., so the present atmosphere might be derivec:tfrom the other gases. However mis-matches in the proportions •of crucIal. cbmponents indicate that the present atmospheres of the Jnnerplanets are not derived from these gases. These crucial components include non-radiogenic isotopes of various noble gases other than Teaching Earth Sciences: vof. 23, pt. 3 (/998) The Origin of the Atmosphere First hypothesis: the Earth was formed with an atmosphere - a primary atmosphere - that proceeded to evolve to its present composition. 730 AUTUMN 1998, Issue 23 TEACHING PRIMARY THE WATER CYCLE Published by the Earth Science Teachers' Association Registered Charity No. 1005331 KSl Geography Places Pos 5c. Effects of weather on people and their surroundings. KS2 Geography Thematic Studies Pos 7 Rivers Thematic Studies Pos 8 Weather New Science Vocabulary: Evaporate, Precipitate Condense KS2 Pos 3 Materials and their properties Changing materials Pos 2e The water cycle Introduction The water cycle plays an important part in the curriculum and is specifically referred to in Science Materials and Properties 2e "Pupils should be taught about the water cycle and the part played by evaporation and condensation." Important ideas to stress include. • Water was the first recycled material that people used. (You could be drinking the water that Henry VII washed in) • Water is a very plentiful resource but it is finite and clean water is limited by how we look after it. In the new curriculum, with its emphasis on language and maths, it can also be a stimulus for problem solving, data handling, poetry, creative writing, or drama. Language Poems about water. Drama - Try a class assembly based on the water cycle. Maths Recording and handling weather data. Recording experimental data. IT Use the Internet to find out about rainfall in different areas. Record weather data on a database. Write records, poetry or descriptions about parts of the water cycle. The Water Cycle You can start from anywhere but it is a good idea to start at the point the children know best. Talk about rain. Rain falls down and makes puddles, or runs down the drain, or sinks into the ground. Children of all ages can see and experience this and understand it. The topic caI1 be opened from the questions. Where does the rain come from and where does it go. As the Sun heats the water in the ocean, evaporation takes place. The water vapour rises with the warm air and condenses in the upper cooler air to form clouds. When these tiny droplets of water join together they fall back to earth as precipitation (rain, snow, sleet or hail, depending on the temperature). This brings us round to the puddles again. As children widen their experience we can talk about bigger puddles, the rivers and seas. Groundwater and man's influence on the water cycle will be looked at in later issues of PEST. Demonstrating Evaporation • Put some water into a saucer and leave it on the windowsill. In time the water will disappear, ask the children where it has gone. • A damp paper towel on the radiator will demonstrate the effect more quickly. Does blowing on the paper towel make any difference to the speed at which the water disappe~rs? • Try mixing salt with the water. Does it disappear more or less quickly. Is anything left behind?' Looking at puddles Mark out a grid with string in the playground and a matching one on paper. Children measure and draw the puddle at regular intervals. This can be linked with weather recording to show the links between rate of evaporation and wind and temperature. Demonstrating Condensation Take a plastic tray and put water into it (using warm water to start with will help speed the process along). Place the tray into a plastic bag and place it on the windowsill or on a radiator. As the water warms up it will start to evaporate, remove the tray to a colder place for the night. Next morning you should see water droplets condensed on to the inside of the plastic bag. Filled seed trays with clear plastic covers give a more realistic demonstration, (even better if growing plants are included), showing how water vapour comes from the soil and will condense on the colder surface. Other examples of condensed water in the children's environment include steamed-up windows in home or car, steamed-up spectacles when entering a warm room from a cold one, dew on the grass after a cold night. f"A>'f" [PEST. in the National Curriculum S(;II~N(;I~ I K, St I 1 LPLT LPLT LPLT LPLT LPLT 1 2 3 4 5 b ab ab EIS EIS AT 1 2 Issue 1. Fossils Issue 2. Introducing Rocks Issue 3. Soil Issue 4. Mountain Bulldinz Issue 5. Using Rocks Issue 6. Water and the environment Issue7. Weathering and Erosion Issue 8. The Moon Issue 9 Minerals Issue 10 Out and About L Around School Issue 11 The Seasons. Issue 12 Out and About IL Holes in the Ground Issue 13 Fossil Fuels I Coal Issue 14 Planning Progression in Earth Science Teachinjl Issue 15 Fossil Fuels n Oil Issue 16 Rivers Issue 17 Using Your Local Museum Issue 18 Edible Earth Science Issue 19 Early Year GeoIOKY Issue 20 Out and About ill b abc abc ab abc abc ab ab ab b abc abc b abc abc EIS 3 M&p· M&P 1 2 a abc a pp pp pp 1 2 3 Science Attainment Targets d d a abc bd 1. abce b a a b d b d Experimental and Investigative Science. EIS 2. c ab abc abc abc LPLT abed abcde a 3. Materials and Their Properties M&P abc abc 4. Physical Processes abc a abc a b e a d abc abc Some activities may need to be adapted for use in one or other of the Key Stages. b a abc ab abc PP The chart shows the main links with the Science National Curriculwn. c abc a Life Procesess and Living Things bed IPEST. in the National·Curriculum S(~II~N(~I~ I O>.,.-~"'" I Key Stage 2 EIS EIS EIS 1 2 3 AT Issue 1. ,Fossils be c be Issue 2. Introducing b Rocks Issue 3. Soil abed abe b Issue 4. Mountain BuiIdin2 Issue 5. Using Rocks abc I b; Issue 6. Water and the abel abc environment Issue7. Weathering and abel abd Erosion Issue 8. The Moon .i·,;"IX!Li~l.· be '·:,~·}:·::d,:~:,·:>:· :';1 <..a;..;. .. !, :b Issue 9 Minerals Issue 10 Out and About L i;z..~ ...... ;. "1' be l·';__ i';;·:~ Aro~d School ' ........... '...:. < . .'J:.;,~''::>::~~::'::'': . . . .~.\;..;.'. ........... """' ,.,' . .',.... .... '"-. Issue 11 The Seasons. ..".~ .._~ . . ,~·i:t JJ!IIIi:i Issue 12 Out and About n. Holes in the Ground <'~t;labc J abce Issue 13 Fossil Fuels I Coal ",I Issue 14 Planning Progression in Earth Science Teaching ;"Yil>;X;f:~, ,Ode Issue 15 Fossil Fuels n Oil Issue 16 Rivers be Issue 17 Using Your Local . • -..... .·.·.1'····· . I,'· Museum Issue 18 Edible Earth Science Issue 19 Early Year Geology Issue 20 Out and About m bee ',/'b 'bee Coastal Exposures. abclabce .· . · .' ·:.·l.•· . ." LPLT LPLT LPLT LPLT LPLT I M&P 4 5 a abc IM&P I ,Map I pp I pp I pp I pp ;1 I I 2 I b I I abc e d 1 3 c a I2 I3 I4 1 ·fh 'de b c ae <~de b c bed abc d 1 1 ad c Science Attainment .Targets I I I I I I. ae ad 1 1- 1. Experimental and Investigative Science. EIS 2. Life Processes and Living Things LPLT 3. Materials and Their Properties Map 4. Physical Processes pp ~" .r· .' , i ' The chart shows the'mam links with the Science National CmTicu1um. dJ .,,:J Some activities may need to be adapted for use in one or other of the Key Stages. "'1 ':'a'" i'1,","'L.' .. CC:A·.··'f.··,'.' '. . '.,";"'.' :'~'~,:: ' ad' T "1, 'a c [PEST. in the National Curriculum fYI~f)fYRlll)IIY KEY Stage 1 iiSilGSI P P AT 1 131 4 5 Issue 1. Fossils Issue 2. Introducing Rocks Issue 3. Soil Issue 4. Mountain Buildin2 Issue 5. Using Rocks a a la ac a a lafa a ab ab a l;abC 6 I a labe] :4-3 Geographical Skills I I a ab I a I.,• a ·;· .•1 I Il.f, GS 4-5 Places P abc Issue? Weathering and ErOSion Issue 8. The Moon Geography Attainment Target 6 Thematic Studies TS· The chart shows the main links with the Geography National Cwriculwn. Issue 12 Out and About n. Holes in the Ground ~o:~ 13 Fossil Fuels I a I Issue 14 Planning Progression in Earth Seienee Teaching Issue 15 Fossil Fuels n Oil I Issue 16 Rivers I Issue 17 Using Your Local Museum Issue 18 Edible Earth Seience Issue 19 Early Year GeolO2Y I t:::-:~ '1 '1;1 a t';~;;I a 1;~<I·a.1 a 1·"R.lal ab 1 a . I ab I I ab I abc a I I f - a a · ~7r* I I I I I ab a Some activities may need to be adapted for use in one or other of the Key Stages. [ PEST. in the National Curriculum f;I~()(;lll'I)II1{ KEY Stage 2 1 AT 'Issue 1. Fossils Issue 2. Introducing Roeks Issue. 3. Soil Issue 4. Mountain Building Issue 5. Using Roeks Issue 6. Water and the environment Issue7. Weathering and Erosion Issue 8. The Moon Issue 9 Minerals Issue 10 Out and About L Around School Issue 11 The Seasons. Issue 12 Out and About n. Holes in the Ground Issue 13 Fossil Fuels I Coal Issue 14 Planning Progression in Earth Science Teaching Issue 15 Fossil Fuels Oil Issue 16 Rivers Issue 17 Using Your Local Museum Issue 18 Edible Earth Science Issue 19 Early Year Geology Issue 20 Out and About ID Coastal ExPOSures. GB GB P P TB TB TB TB TB 2 3 4 5 6 7 8 9 tn . a ac a abc a ac ab abc abc a ab a 2-3 Geographical Skills . C a a a c ab a a ab abc a a ab a abc ab ab abc Bbc GS -4-5 Places P 6 Thematic Studies TS b ab Geography Attainment Target 7. Rivers 8. Weather 9. Settlement lOEnvironmental Change a The chart shows the main links with the Geography National Cwriculwn. Some activities may need to be adapted for use in one or other of the Key Stages. n abc a a abc abc abc ab abc abc ·ab a . Disc. 1 Mak~ Yout Own Water Cycle Disc. 2 Enlarge Page to required size (suggest 200%). Copy or stick onto card. Cut around circles and cut out windows in second circle. Plasce disc lover disc 2 and push brass paper fastener through ~oth. Open up fastener at back. Front disc should revolve aroUIld with window~ showing the stages of the water cycle. Work with clouds Mark a frame on the classroom window with paint or paper, observ~ and draw the clouds seen through it at regular intervals through the day or at the same time each day. Use reference books to find what the different Cloud shapes are called. Cold days offer an opportunity to produce clouds by breathing out. Precipitation Precipitation is difficult to demonstrate in the classroom, but this problem is easily overcome in this country by the abundance of opportunity to observe rain in th'e playground. Make a rain gauge from a plastic lemonade bottle (or use a commercial one) and keep records of rainfall in your area. Are certain areas in the school grounds protected from rain? If they are how is this done? What difference does this make to plants growing there? Water Cycle Wheel On page 3 is a cut-out to make a model demonstrating the water cycle. Enlarge it to an appropriate size and copy onto card or glue onto card. Cut out the two windows in disc 2. Place disc) over disc 2 and push a paper fastener through both discs open it up at the back. Disc 1 should now revolve freely, the windows showing stages in the cycle with simple explana~~ , COPYRIGHT There is no copyright on original material published in Teaching Primary Earth Science if it is required for teaching in the classroom. Copyright materials reproduced by permission of other publications rests with the originating publishers. To reproduce original material from P.E.S.T. in other publications permission must be sought from the Earth Science Primary working'group via: Jennifer Claringbold, 99 Otley Road, Harrogate, North Yorkshire HG2 OAG This issue was written by Stewart Taylor and many of the ideas were tested by staff and pupils arWren's Nest Primary School, Dudley, W.Mids. Edited by Graham Kitts. To subscribe to Teaching Primary Earth SCience send [5,00 made payable to ESTA co Mr P York 346 Mlddlewood Road North Oughtlbndge, Sheffield S35 OHF The 1993 and 1994 Issues are still available at a speCial price of £5 00 each year from the same address, helium in which the atmospheres of inner planets are considerably depleted. It is also highly unlikely that such a primary atmosphere for the Earth would have survived the intense solar wind emanating from the early Sun. All the inner planets are too dose to the Sun in this respect, and only the outer planets are likely to have retained such primary atmospheres. Conclusion: Earth's primary atmosphere, ifit did exist, was lost at a very early stage. Second hypothesis: the Earth's present atmosphere originated from out--gassing from the planet itself, during accretion and formation of the core, which produced a secondary atmosphere. As material accreted to form the. planets. small molecules wer:e trapped and then released gradually during the early evolution of the planet. Evidence for the presence of volatiles (gases and volatile liqUids, all of which are composed of small molecules) trapped inside such material comes from the type Present composition of Earth's atmosphere· Nitrogen 78.08% Oxygen 20.94% Argon 0.93% Carbon dioxide 0.0335% Neon 0.0018% Helium 0.00052% Methane 0.00017% Krypton 0.000114% Hydrogen 0.00005% Dinitrogen monoxide 0.00003% Xenon 0.0000086% variable < 1% variabl.e amounts trace Typical composition of volcanic gases Oxygen 0 0.2% Argon Carbon dioxide 11.8% Water vapour 73.5% Sulphur oxides 8.9% Hydrogen 0.4% Others, gases including noble 0.5% Table I. Composition of the Earth's atmosphere, and of volcanic gases. Teaching forth Sciences: vol. 23, pt. 3 (1998) Modern volcanic out-gassing produces all the components of the present atmosphere except oxygen, as well as water and some other important components of the oceans. The rate of out-gaSSing has probably decreased steadily over time from a very intensive early stage. Outgassing processes themselves probably involve high temperature chemical reactions within the magma, rather than just gases escaping from solution. Conclusion: ifit can be shown how known processes can result in a change from such a composition to that of the present atmosphere, then this second hypotheSiS looks promising. Hydrogen sulphide, SUlphur oxides, carbon monoxide, ammonia 4.7% Most of these trapped gases were probably released to form the early atmosphere in the first billion years of our planet, but present-day volcanic emissions show that out-gassing is still happening. Indeed it may well have been necessary in the early stages of planetary formation for the accreting material to have melted to form a magma before the trapped volatiles could be released. Present day volcanic gas emissions may therefore represent a continuation of the same process, and thus give us valuable information about the possible composition of the original atm9sphere. It is useful to compare the present atmospheric composition with that of a typical volcanic emission from active Hawaiian volcanoes (Table I). This hypothesis is capable of extension to explain the formation of atmospheres for all the inner planets, with differences in the compositions of their present atmospheres being the result of different processes under different conditions. Water vapour Nitrogen of meteorites called carbonaceous chondrites. These contain volatiles, including the non-radiogenic isotopes of the noble gases in similar proportions to those found in atmospheres of the inner planets. Third hypothesiS: Earth acquired a secondary atmosphere as a result of bombardment by meteorites and cometary material bringing volati/es with them. This could be anything from a minor supplementary contribution of volatiles, to a major contribution in its own right. Recent claims, based on interesting sightings of incoming objects, that the Earth is being bombarded by large 'snowballs', which could be responsible for much of the water on the planet, have been greeted with some scepticism; Until more evidence is established, this has to be regarded as the'oddball' hypothesis - but such hypotheses have in the past turned out to be successful in the end. Conclusion: let's keep an open mind on this one, but it doesn't look to be a strong contender at the moment Where did the oxygen come from? Let us take the second hypothesiS above as our working hypothesis. So how did free oxygen come to be formed? From a thermodynamic point of view, the creation of an atmosphere containing 20% free oxygen seems a most unlikely event, so the explanation had better be good! First hypothesis: free oxygen was formed as a result of chemical processes acting on the origihal components of the atmosphere. By analogy with the composition of volcanic gases the original out-gassed atmosphere would have contained mainly carbon dioxide, water vapour and nitrogen. What possible chemical processes acting on this mixture could produce free oxygen? 131 I.. Mosf of the water vapour would have condensed as the atmospJ,ere and planet.cooled, producing the first oceans, but therewoufcr always be some in the atmosphere. With no oZOne layer, ultra-violet radiation from the early Sun entering the atmosphere would be intense. Ultra-violet radiation of Wavelengths below 200 nm is a,bscirbed by water molecules leading tcj the breaking of hydrogen,:oxygen bonds to form hyqrogen. OH radicals and even atrac:e offree oxygen. Most of these would rapidly reconibine to form Water, but some hydrogen wiU.escapefrom the atmosphere. and eventually a tiny equ~ibrium concentration of oxygen would be achieved. The maximum partial pressure of oxygen due to this process is estimated at about 5 x I 0-9 bar. (Rothery, 1994) 2. Sedimentary rocks older than about 2.5 bUlion years contain readify oxidised miheralssuch as pyrite, FeS2, and uraninite, Ups. The thermodynamics of their oxidation set an upper limit of 2.x 10-4 bar on thepartiaf pressure of oxygen while significant amounts of these minerals remain in contact with theq.tmosphere in the rock cycle. The same sedimentary rocks also contain magnetite,. Fe,O4' whose formation requires the presence of free oxygen, esti~ mated to require a partial pressure of at least 10- 11 bar. So the partial pressure of free oxygen. must have been between 10·1[ bar and 2 x 10-4 bar around 2.5 billion years ago. (Rothery, 1994) There would thus have been a balance between the production of, free oxygen by photo-dissociation and its removal by reducing gases and minerak • ancestors of the. modern cyanobacteria (sometimes .cal.led the blue-green algae) which are able to pootosyntnesise in the usual way. 4. From toe fossil record of the Archaea, the~e organisms were probably the first to evolve the proc:essofphotosynthesis some 3.5 billion years ago; ancestorsofthe s.utphurbacteria may even have been the first living organisms. 5. The eukaryotes, in which the cells contain their DNA in a nucleus, appear in the fOSSil record about 2billiC)tl YE*lrsago; in order to function, they re<juire a partial pressure of oxygen above 10-3 001" (Rothery, 1994). 6. Soft bodied metazoan animals (such as jellyfish); Which absorb oxygen from solution in water through theIr exposed surfaces, appear in the fossil record about 600 million years ago; for this prQcess they require a partial pressure of oxygen above 2 x 10-2 bar (Rothery, 1994). 7. Land plants appear in .the fossil record about 450 million years ago. S. Land animals appear in the fossil record about 4()() million years ago; for air breathing, they require atmospheric oxygen levels about the present value. 9. Luxuriant forests flourished around 300 million· years ago, and there is eVidence· for. frequent forest fires thq.t indicate higher oxygen levels than the present value. . 10. The level of atmospheric oxygen has probably varied around its present value since about 200 million years ago (Nunn, I 99S). Condu$iQn: the early atmosphere probably did contain free oxygen in trace amounts, but the chemio:aJ process.es taking place c:ould neyer haye made it a major component. Indeed this mechanism is the likely source of the traces of free oxygen found in the atmosphere of Mars. Second:. hypothesis: the proportion of free oxygen in the present atmosphere is the result of biochemical p1'Ocesses oaing on the original components of the atmosphere. Now we do have problems, for we need information about the,.ev<>.lution of the· biochemistry of different types of organism, many of them now extinct. S.uch evidence for the earliest organisms is distinctly limited, but we wiU try to assemble a coherent story. L The earliest organisms known from the fossil record belong to the Archaea, and date from around 3.5 billion years ago. Indirect evidence suggests Jiving organisms were present 3.8 billion years ago. 2. Archaeaarethe most ancient life forms; they are prokaryotes - that is,. they have no cell nucleus to contain their DNA, sharing this characteristic with the Eubaaeria. 3..Members of the· Archaea known from the fossil record include: • ancestors of the modern purple and green sulphur bacteria whiCh Jive around hot springs, fumaroles .and hydrothermal ventsati:emperatures around IOO<>C; these photosynthesise using hydrogen sulphide as the source of hydrogen, rather than water. and hence produce sulphur instead of oxygen; TeaChing Earth Sciences: vol. 23, pt. 3 (1998) Plotting this data as a graph. we obtain a broad picture (Figure I) of the progressive. evolution of the oxygen content of our atmosphere asa result ohhe evolution of biochemical processes. (For a more detailed picture over the past 600 mrllion years, see NUM, 1998.) Yet why was there a delay of more than 2 billion years before this dramatic increase to present levels in the last 600 million years? Evidence from the fossil record - and biology With no ozone layer to protect early ~fe forms fromu[traviolet radiation, which causes radiation damage to, DNA, life at the Earth's suria<::ewas impossible, The onlyproteUion from radiation would have been in water deep.enolilghto.absorb this radiation - esSentially a few me.tresdepth. eut n~t so deep as to prevent the evolution of photosynthesis. Throughout the period, Archaea remain the only common life forms, and it is probably relevant that Archaea·areitoday the most resistant of all organisms to s.uch radiation damage. The build-up of the ozone shield probably required about 0.5% oxygen in the atmosphere. Evidence from the rock record Certain elements in the rocks act as 'oxygen indicators', as they are readily oxidised or reduced according to conditions in particular iron, sulphur and uranium compounds. 132 5 O+-----~------~------~----~==~~~==~=+====~~~=-_+------'I------41 o 0,5 1,5 2 2,5 3 Age of Earth/billions of years ~,5 4.5 5 Figure I. Evolution of the level of oxygen in the atmosphere. Iron is a major component of most rocks, and in the presence of water and oxygen is readily oxidised from Fe(II) to Fe(III). Common rock-forming minerals containing Fe(lI) are usually dull and dark in colour, while minerals containing Fe(III), particularly oxides, range in colour through yellow, orange and red. Basaltic igneous rocks in particular contain Fe(lI) minerals, which in the absence of oxygen weather to form sediments which are also dark in colour. But if oxygen is present during the weathering process, Fe(lIl) compounds are formed and yellow/red sediments are produced. The first red beds appeared 2.2 billion years ago. Before this. the small amounts of oxygen being produced by photosynthesis were removed by oxidation of a small part of this iron. Red beds become more common very slowly, and only when a high proportion of the iron in the rock cycle exposed to the atmosphere was present as Fe(llI) could a rapid bUild-up of oxygen levels begin. This is assumed to have happened about 0.6 billion years ago. Where did the carbon dioxide go to? From an estimated 80% of the original atmosphere to 0.034% of the present atmosphere; that's a lot of carbon dioxide 'gone missing'! There are two possible sinks: • dissolution in sea-water • photosynthesis and these are inter-related. The essential chemistry can be described by two equilibria: C~(g) + aq lE ) C02(aq) ( Teaching Earth Sciences: vol. 23, pt. 3 (1998) Hydrogencarbonate ions can then be removed by two processes • formation of insoluble carbonates, e.g. CaC0 3(s), both by inorganic precipitation and by organisms forming calcareous shells. • photosynthesis by aquatic organisms to form organic compounds, which after death may oxidise back to atmospheric CO 2, or form organic deposits (coal and oil) thus transferring the carbon to the lithosphere. Carbonate rocks, in particular limestones. are known from 3 billion years ago, but only became common about 2 billion years ago. They become increasingly abundant from 0.6 billion years ago, which suggests that biological processes have been more important than inorganic chemical processes inremoving CO 2 from thea~moSPhere. The net result was a gradual decrease in CO2 level until 2 billion years ago. then a rapid decrease to present level as photosynthesis produced a rapid increase in oxygen level. And how about the nitrogen content.? At first glance this would appear to have an obvious answer, yet it is difficult to find any reference to consideration of the evolution of the nitrogen content, if only to support the obvious hypothesis that it just stayed there aU the time while the other gases got on with their more reactive life-styles. Perhaps someone reading this article might care to work through the calculations to estimate the rate of removal of nitrogen from the atmosphere into the biosphere (and to some extent to the· hydrosphere and lithosphere),ahd thUs work back to an estimate of the pre-biotic quanti~ofnitrogen in the atmosphere. But then nitrogen is a major component of present volcanic out-gassing, so we also need to estimate the likely increase in atmospheric nitrogen over time from this process. 133 Perhaps there is a degree of re.-cyding of nitrogen (and other atll1ospherlccomponents) throughpJate tectonic processes, andsQrne of the nitrogen presently being outgassed has been round 9nce before. Again, netice the stdphur 'Oxides in 'folcanicgases, which presumably dissolve in the oceans as slllphateiOJ;lsj a similar set 'Of questions must arise fer sulphur. .And how about argon? Notice the ratios ofargon to nitrogen in the present atmosphere (about I:80) and·!n volcanic gases (about I:23)- very different. yet both are essentiarly chemically inett.. Perhaps the high argo:n .content ofthe volcarlic gases is due to argon produced by ntdioactive. decay of potassium-40 irlthe Utho:sphereand mantle. Many intriguing questioris come to the mind of the interested teacher trying to gaiQ.a coherent insight into the evolution of our atmosphere - an insight sufficient. to: form the basis of a coherent story on which to base informed teaching of this statement in the Science National Curriculum. Conclusion This artidedidnot setoutto propose a teaching approach for this topic, butto bring the attentiorl of teachers ofKey Stage 4 Science to our present understahdlngof atmosphericevolution. How this topic might be taught to 16 year aIds is another matter,but wha.tever is taught should be ·informed by a more substantial understanding than that given in most books accessible to science teachers. However those who wish· to go more fully into this story should ~oto the excellent texts for the Open University courseS269, in particular 'Origins of Teaching Earth Sciences: VOl. 23, pt. 3 (7998) Earth and Life' and 'Atmosphere, Earth and Life'. Note that the Science National Currh:ulumstaternentalso concerns the evolution of the oceans, and this has. only received thebriefest of mentions in this arti:ele. HQweve,-thatJs another story,andafascil1atingone in its ownrighl Further Reading Francis, .P., and Dise. N. 1997. Atmosphere, Earthqnd Life. Milton Keynes, Open llniversity.(ISBN 0 7492.81841) Gilmour.l., Wright.l..andWright,J. 1997, Origi(1s 9(Earth and life. Milton Keynes, Open University: (ISBN 0]492 81820.) References Nunn. J. F. 1998. Evolution of the Atmosphere, .Proceedings af the Geofogists' Association, I 09,1-/3 (This also gives a good range of recent research references) Rothery, D. 1994. Atmospheres of Terrestrial PI~!",ets. to: The Planets: Block 20fC9urse 52St, Astronomy and Planetary Science; Milton Keynes. Open University. Alastair Fleming I)epattmentof Education. Kee1eUniversity Keele Staffs ST55BG 134 'Science of the Earth' - past and present Chris King and Peter Kennett The Idea In the 1980s there was very little published material available to help science teachers to teach Earth science, apart from some GCSE and 'A' level geology textbooks that usually gave little emphasis to practical laboratory work. The few 'pupilfriendly' books that were available which did include practical approaches (eg. Atherton and Robinson's 'Study the Earth' series, Norman Dutton's 'Darlaston Geology Project' and Peter Whithead's 'Reading, the Rocks' booklet) did not have wide markets. It Was at this time that the Association for Science Educ~tion (ASE) had begun publishing its Science ,and Technology in Society (SATIS) series in, what became a successful attempt to bring relevant science to school classrooms. Their model of pupil worksheets with teacher notes that could be 'taken off the shelf easily by science teachers and incorporated into their schemes of work was a novel but attractive approach. Having seen" these SATIS units, Peter Kennett (PK) had the idea that ESTA should use the ,same approach to bring practical, relevant and 'pupil-friendly' Earth science in 'off the shelf booklets to science teachers. When he discussed this with Chris King (CK), they realised that if ESTA was going to do this, then they had to take the lead. A new venture for ESTA For ESTA to take on a new venture, funding was required and so one of the early tasks was to write bids for funding to various organisations. Over the years, funding has been provided by a number of sources and organisations, to whom we are most grateful. They are listed in Figures [ and 2 below. The funding allowed ESTA to do the follOWing: • to enable the two teachers (PK, CK) who had prepared the successful bids tobecome the coordinators of the 'Science of the Earth' initiative; • to run a working weekend at the start of each new 'Science of the Earth' project. This allowed a group of ESTA members to meet from a Friday night to a Sunday lunchtime to write first drafts of the new 'Science of the Earth' materials; later, to release the two teachers (PK, CK) from school for one day per week to become co-editors, joined in the final stages by Peter York; • to pay for the draWing of diagrams, purchase of photographs, design of the publications, and setting and printing of a thousand copies of each title. The 'Science of the Earth' approach Since the tradition in UK schools has been to teach science through laboratory-based activities, the approach we chose was to develop a series of new practical activities that could be ,used as the basis for lessons, since we felt that science teachers would be comfortable with such a practical-based approach. We were well aware that most science teachers knew no Earth science and so we tried to make their job as Teaching Earth SCiences: vol. 23, pt. 3 (1998) simple as possible by presenting the activities in a series of worksheets, written for pupils. Through a series of teacher notes, the teachers were given considerable guidance on how to conduct the lessons and the answers to any questions posed. We hoped that teachers would take these ready made lessons 'off the shelf and be able to slot them easily into their own teaching schemes. . The result has been the series of thirty s,even publications shown in Figure I. Some of these have now been translated into Spanish and Welsh. Evolution of the project The Table in Figure I shows that our publication ideas evolved through the following phases. Early 'Science of the Earth' units comprised a series of pupil worksheets on a single topic, with teacher notes. .They were written as the first and second versions 0.£ the National Curriculum were developed. The activities would take about three hours to complete and could be divided up into a series of lessons. SQlne of these units have been very successful but others were considered too long or too specialised by many science teachers. Also, if all had been taught, theyw.oulo have occupied much more time than ~s available: for the teaching of Earth science in the curriculum, and would have been expensive to buy. The 'Science of the Earth II - 14' series has been.produced as booklets, each containing pupil worksheets for three free-standing one hour lessons on each topic. Eadllesson also has teacher notes. They were mainly written to match the 1992 version of the Nati.onal Curriculum, but are still appropriate for the current (1?95) version. Whilstmany science teachers like the ideas, they say that the W'orksheets are not appropriate for their pupils for various reasons (such as tbe reading levels or the length of time needed to cover the full activity). They can become rather overwhelmed by the large number of lessons contained in all the units (thirty six) to be fitted into the small time available for teaching Earth science and by the cost of buying all thirteen booklets (now reduced to £25 total). The 'Investigating the Science of the Earth' series. has been written for teachers. Each covers a large topic area in the current National Curriculum (1995 version), and cO':!tains ten sections with one or more activities on a particular sub-topic. The ideas are intended to be taken by teachers and reworked in a suitable way for their own pupils. This provides flexibility and allows many ideas and activities to be published at low cost (£8.85 for all three booklets). 'Routeway' represents the sole venture into writing for older students. In spite of· being accompanied by five free copies of a specially designed colour photo poster, the unit remains under-used. It is however, now proving highly appropriate for teaching the engineering geology aspects of some current A Level syllabuses and is remarkably good value at £4.95. 135 Devisor af Unit l1tle SOOrce of ISSNNa. Funding Publi NO. cation pages rCu~t iPrice Date ~S$Fig. 2 : 'science ·ofthe Earth' $erleScfor 14 ~ 1$ year aids ~ .ch. cont;aininQa $eriesofsi)fwotl(.beet:~ lessons ; . o 9501'03.1 28 1990 . 74 .·:£7. 0,0 Ohlts1"';' 5 Combined volume 1.WilJmy gravestone I8Sf Peter Kellliett GA .' GA Peter Brannlund .2.tIilrtf:tq1.lttk8S: danger .~ath our ff#it '. 3 .. Flu(jnspar: is it worth. mining? Peter Kellnett GA ChrisKing GA 4~ BUltdihg sedimentary SfroctuteS: in ,the lab and millions .of years 'ago Ken Bland GA 5 .. Waste qnd the. hole in the groundprobJem £7;00 o 9501(}317 9 1991 UmlS 6 ,.. 10Comblned volume 82 June Warren ~. Nuclear waste: the way GA forward? Frank. Spode GA 7.. M:ighbourhoOJ;f stone watch 8. Mrilfjngground Slmori Elsy GA GA '9,·GrotJfJawafer supplies: a Adrian Cook mode.m Jack and Jiff story GA 10. Astrpgeology anQ the clues Peter Brannlund on the moon . . 1991 95 £7.00 Units 11 -15 Combjm~d 09501031 60 .' .' ; yolume water 11. The. cycle: a natural ree'fl#iiJg· P{OOfJ!ts .' Roger Trend GA t2];WhiCfi..··~stQne. MilWluke 13Cthe 1time. scale ;<f.4;'Who'sfOF.8 hot· tight Peter'Perkins Oavid Thompson GA GA, NCC GA. NCe 15.·Rock poweri Geothermal Adrian Cook GA, NCC ~q~ejninner st:Ja<;er eneFflY, r$OUttes Unit~,16 - 20 Combined volume 1S.Earth's 'patchwork crust: ,SP introoucfion to plate .tectonics '.17...CooIc· it!:./iquid ~gma to .solid··rock . 18;~ ofthe Earth. :c " , 19, The day the eqtth erupted: ;v~noes ' 2t1. S;,():S.- save our sites: fiaJth science conservation in .action 1873266006 Philip Lee GA, Nee J,ohn Collins GA, NCe GA, NCe Sheffiel.dGeology Teachers' Group Oavid Leather t990 £7.00 100 " GA, NCe " Dunesn Hawl:ey GAt NeC Figure I. The development of ESTA 'Science fo the Earth' publications. 1990 - 1998 Teaching farth Sciences: vol. 23, pt. 3 (1998) 136 'Science of the Earth 11- 14' series for 11 -14 year ords - each containing three worksheet-based lessons Groundwork - introducing Earth science Life from the past - introducing fossils Hidden changes in the Earth introducing metamorphic Peter Kennett PE 0950103187 1990 28 £2.00 I Peter Kennelt Chris King Philip lee; Peter Kennett; Margaret Pemberton PE 0950103195 1990 28 £2.00 PE 1873266,01 4 1990 20 £2.00 PE, HSTS ·09501031 X 1990 32 £2.00 PE, HSTS 095010336 1990 32 £2.00 PE, HSTS 095010344 1991 30 £2.00 ~rocesses Power from the past - coal Magma - introducing igneous processes Secondhand rocksintroducing sedimentary processes Bulk constructional materials Steps towards the rock face introducing ·fieldwork Earth's ·surface features Power source: oil and energy Water overground and underground Moulding. Earth's surface weathering, erosion and transport Teachers' Guide to 'ScienCe of the Earth 11 - 14' Frank Spode; Peter Cotterel!; John Reynolds; Nick Smith Chris King; Margaret Fordham; Robert Smith; Peter Kennett; Adrian Marks Maggie Jarman; Julie Warren; Peter Kennett; CMs King Margaret Pemberton; Peter Kennett; Roger Trend Juiie Warren; Peter York; Margaret Pemberton Philip Lee; John Reynolds; Peter Kennett Eddie Fogg; Colin Ross; Maggie Williams Adrian Cook; Chris King; Nigel Roberts Dee Edwards; Alan Rhodes; Keith Pointon The Editors ~ PE, HSTS RMC PE, HSTS PE, HSTS Shell, PE PE, HSTS PE PE, DCCT 095010352 1991 32 £2.00 1873266 03 0 1991 32 .£2.00 1873266 04 9 1992 36 £2.0() I .. 1873266057 1992 32 £2:00 1873266065 1992 36 £2.00 187326 073 1993 24 £2.00 187326081 1993 8 £1.00 'Scien~eof the Earth - applied Earth science'·for 14 - 19 year olds - containing three worksheet-based lessons 1994 £4.95 Routeway:solving Laurie Doyle;. Peter DCCT 18732609 X 32 constructional problems Kennett; Julie Warren 'liwestigating the Science of the Earth' written for teachers of 14to 16 year old students, 10 activities that can be used as a basis for lessons SoE1 Changes to the Dave Turner; Peter York; DCCT 187326103 atmosphere Chris King; Alastair Fleming ; loe Fleming; Peter Kennett John Reynolds; Maggie DeCT 18732612 X SoE2 Geological changes Earth's structure and plate Williams; Peter Kennett; Chris King; Peter York tectoniCS DCCT 187326138 Chris King; Peter Kennett; SoE3 Geological changes rock formation and deformation Keith Harvey; Steve Tomlinson each containing a set of . 1995 24 £2.95 1996 32 £2.95 1998 24 £2.95 'Science of the Earth' series editors: Peter Kennett and Chris King. 'Science of the Earth' publications are available from: Geo Supplies Ltd., 16 Station Road, Chapeltown, Sheffield, S35 3XH, UK. Tel 0114 2455746. Fax. 01142403405. figure I continued Teaching Earth Sciences: vol. 23, pt. 3 (1998) 131 CodeJrol1'I GA NCC,"., PE , Source of Funding figore,1 ThE! Geologist's Association Fund Natur:e Con:servan<::y Council , ,," Project Earth - a joinUnifiative by ESTA, the Department of Earth Sciences and the Centre fprScience Education oHM OPen University, sponsored at different times by: Amerada Hess British Coal Deep Mihes British Coal Opencast Chevron Oil English China Clays (ECC) Mineral, Industry Manpower and Careers Unit (MIMCU) Nationwide Geology Club, Natural Environment Research Council (NERC) Nuffield Foundii1iol1 Hertfordshire Science Teaching SCholarship RMCGroup PLC ". Shell Education Service, .Shell UK DennisCurry . Charitable Trust ; , I ~' HSTS RMC .. Shelf DCeT .; ; Figute 2. Sources of 'Science of the E.arth' funding Thefatest 'Science of the Earth' publicat.ons (i.e. the 'Investigating the Science of the Earth" series) This latest series of publications seems to have been most successful in terms of cost and flexibility, and the activities covered by them are shown in Figure 3. All the publications have their photocopy rights, waived for classroom teachers to allow photocopying and use of the . materials in schools. A successful conclusion Overall, the sales "of Science of the Earth materials have not been huge. , But since publication was paid for by the, charity funding. they have provided a srnallbut steady income to ESTA over the years. One of the problems has been that. while the materials were being prepared for publication, the National Science> Curriculum was being rewritten, so that sometimes, when they appeared,. they were not·.dire~ly relevant to the new version of the Curriculum. However, overan they have been vetyimpottant, because many of. the ideas have been taken and rewritten to appear in science textbooks for I I - 16 year olds (usually unacknowledged) and so have become widely used. The ideas have also formed the basis of many In.S~rvice Education and Training (INSET) sessions provided by .ESTA members. ;tUowinga good number o(individual teachers to be helped with their Earth science teaching. No further 'Science of the Earth' publications at secondary level currently are planned. However, there remains considerable mileage.in most of the .later units. If you haven't seen diem, do. investigate. them. If they do not apply: to your own teaching, they can be shown to colleagues in Science and possibly Geography Departments within your school. In the editors'experience, a few ready made lessons such as these, with technical support from the geology expert are well received, and will be taught. Teaching Earth Sciences: vol. 23, pt. 3 (1998) Acknowledgements Many ESTA members and others have. helped us In. the checking, production.anddistribution of the units. and. by providing.generalsupportand wewot.iJd like to th~nk them all. Witho.ut their help the publication of 'Science of the Earth' . would not have been possible. They include: all the authors (already listed); our technical readers and advisors: Lloyd Boardman' {BNtlshCoa\, deep mines); Reg' 8radshaw; Mike Brooks; .Tim Colema.n (British Geological Survey, BGS); Anabel Curry (DermisCutry Charitable Trust); .Trevor.~ord; A1an Forster(BGS);.G.Jones; GlyrtnJones;MikeHarley: (Nature. COrlservancyCouf)cil); John Holman {Editor of Science and Technology in SOCiety, SATlS); Dayid Higf1ley:(BGS); Sir John KnHI; RQger Mason; Prof. John Mather {Royal Ho/loway); John McClatchey (Royal MeteorologiG:aISociety); Richard Myerscough; Don Mackean; A. McKirdy (Nature Conservancy Council); Geoffrey.· Nowell; .Kevin . Pickup· (British Coal Opencast . Executive); Riehard Porter; EricRQbinson (Geologists' Associa,tion): C.Stevens (NatureConseM.ncy Council); Brian Taylor(BGS};.Peter Toctan; Suzanna .van Rose; David Walker (Association for SciElnCe . Education); Chris VValmsley (Brl~ishCoal Opencast Executive); Dave Williams; Chris WHson. our artists and those who drafted diagrams for us: . C. T. Bass; Anna Brace; Alan Birchall; HetenBusteed;Sue Churchman; DominkGreenall; leWis Jones; Sharron Knight: Sandra Thompson; lan Waiters; and those involved in production and distribution: Geoff Nicholson; Colin Ross;.Makolm Fry; Ray Balmer; Fran Stratton; Jeff Kay; Paul TQwnsend; the G~oSuppliesteam Chris Darmon; Len Sims and Kath Grant. 138 SoE2: Geological changes SoE3: Geological changes - Rock Earth's structure and plate formation and deformation tectonics The ten activities in each booklet, each with a range of ideas and suggestions for use in lessons \Mly is it hot at the equator and Weathering - rocks under attack Model Earth - a simulation of density contrasts in the Earth's cold at the poles - the radiant structure heating of a sloping surface The great energy filter - Earth's Sedimentary structures - clues to Earthquakes - the slinky simulation atmosphere the past Water cycle workout Earthquakes - waves in the Earth Porosity - and fluids in rocks Sun, sand and sea - radiant heat Earthquake shadow zones Oil trap - modelling deformation in and temperature changes in solids rocks and liquids Circulation in a shoeboxClues to sea floor spreading from Magma - from buried batholith to investigating air circulation the magnetic ocean floor - a violent volcano simulation Atmosphere and ocean in motion Rockforce - investigating pressures' Metamorphism - transformations how do fluid flows interact? on the rocks beneath your feet underground Balancing the carbon dioxide - where Plates in motion The rock cycle - how rocks. are does it come from; where does it made from other rocks go? The global carbon cycle Plate tectonics - the earthquake and The record of the rocks - sorting. out volcano evidence the seqlJence Creating the atmosphere Drifting continents Geological time - an immense scale Britain's changing location Earth's changing climate - the ice How to date a rock core evidence evidence from the rocks SoE': Changes to the atmosphere Figure 3. The content of the latest 'Science of the Earth' publications References Atherton, M and R. Robinson. 1980, 1981. 1982. 'Study the Earth': 'Rocks and Earth History; Air and Earth; Water at Work; Useful Materials from the Earth. Hodder and Stoughton. Dutton, N. W. 1979, The Oarlaston Geology Project'. Darlaston Comprehensive School. Whitehead, P.S. 1989. Enterprises. 'Reading the rocks'. Rocky Rex Chris King Department of Education Keele University Keele Staffs ST55BG Peter Kennett 142 Knowle Lane Sheffield Sit 9SJ Teaching Eorth Sciences: vol. 23, pt. 3 (1998) 139 "DES~RtfSLAND EXPOSURES: LlSAN PENINSULA. JORDAN John Knill Location The Lisan Peninsula isa protuberance from the eastern. shore of the Dead Sea. ThePeninsu/a formerly separated the small Southern Basinfrom the main. northern body of the Dead Sea.. However, natural sedimentation and the construction of brine evaporation pqnds in both Israel and Jordan have now. infilled the Basin which is divided by a flood channelwhich defines the Truce line. Jord~nian The geology The Peninsula is located within the Dead Sea-Jordan Rift System which developed in thE! early Miocene as sea floor spreading commenced in the Red .Sea and the Gulf of Suez. La:teral fault movement resulted In the formation of pul/"apart grabenswhich resulted in a succession of lakes. and in which thick clastic and chemical sedimentsaccumulated. The bulk of the Peninsula is formed by a Jevel-tdPped, triangular in plan. hill of the Usan .Formationwhich was deposited between 80.000 and 11,000 years BPin a lake which stretched from the Sea of GalileeIn the north to 20 km south of the Southern Basin. The maximum elevation of this Lake Usan was - lOOm (remember we are below ocean sea level and the current Dead Sea level is about -4/00"1) and the softlyweathering Usan Formation forms spect<tcular e}(.posuresmantling the sides of the Jordan valley. Geophysical evidence suggests that part of the Peninsula is underlain by a salt dome, the dome occurring nearby at Mount Sedom in Israel being visible across the Sea. Why is this my favourite exposure? sequence of aragonite-calcite clays, silt. and. sands.... Althollgh the Jnineral. partides are chemical in. origin, theSuc.e;ession contains abundant shallow-water sedimentarystructures.T~re Is Spectacl1larintra-fQrmational foldjngascribedas the product ofsubaqueouslandsHding triggered either by earthquakes or sediment ·overloading. Samples recovered· from . below the water table are "qulck"; being qwte solid in the.. hand but turning to liquid once moulded by finger pressure. The Usan foreshore is covered. by a variety .ofsedimE!ntary facies including superb stromatplites (Photograpb2). different varieties of salt crust, .sandsheets, beach ridges and springdeposited saline·deposits. The stromatolites atecommollly mounded on, and interbedded with, prganic material; fossil logs lying on the beach are encased in algal layers. The activity ofthe geological environment is overwhelmjng~ A recent. fault crosses the western foreshore and displac:es the sttomatolites by about·' to 1.5 m creating a step· tnthe beach profile. The lineofthefauftis locally associated with small mud volcanoes (Photograph· 3) induced by.seismic pumping. Evidence for res::ent activedispJacement can also be seen inland on the top of the Peninsula.. Sinkholesoccur both On the foreshore and elsewhere {Photograph 4). In one small area over 300 such sinkholes have been counted forming an intense clustering of ~raters ~long a narrow linear feature for about. a kilometre; .Srine. springs, with extensive associated salt deposits,occut. above Dead Sea level demonstrating the presence of active groundwater. movement. The western foreshore is occasionally inundated by fresh water duriog the floods which now northwards along the TruceCharmel. This results in rapid solution-induced erosion ofthe salt crust and the triggering of sinkholecollapse which b:reakupthroughthe overlying, flood-deposited cover of vegetation (Photograph 4). I have never met so much interesting geology in so small an area. What is its teaching potential? The Usan sediments are superblyexp.osed (Photograph I) along the sides of the Peninsula being composed of a laminated The potential is enormous though it is doubtfulthatanyone has used it for that purpose.. Until a few years ago access to the area carried risks and even now. it is necessary to watch Photograph I Teaching Earth Sciences: VOl. 23, pt. 3 (/998) Photograph 2 140 tive tectonics. All this can be readily observed within the regional context of the evolution of the Jordan valley. .The sediments (including the stromatolites) are weak and can be readily excavated enabling the three-dimensional structure to be observed. Good book.... The Bible, standard fare for desert islanders, would be brought alive because many biblical· sites are so close. I would,of course, avoid Sodom which was reputedly located in what is now the inlet at the southern end of the Dead Sea on the eastern side of thelisan Peninsula. My daily view would include Masada stormed by the Romans, ahd Karak of Crusader fame. Photograph 3 My book would be Oman's multi-volume History of the Peninsular War together with the best sets of geological and topographic maps of Spain and Portugal available, and full air photograph cover. Geological lUxury The most sophisticated earthquake monitoring system available, and connected to geophones located throughout the region. In addition, very user friendly hard and software which would enable me to quickly analyse the data which I would acquire daily. The problem would be the requisite electricity supply although solar panels and batteries might provide a solution.· As if I had not enough to do already I would request the indulgence of the Editor to take with me the largest selection of the world's teas available in order to continue my researches on the influence of water that boils at over IOO'C on the flavour of tea. Photograph 4 out for mines on the foreshore which floated in when the Dead Sea Was higher. It provides a quite exceptional opportunity to study the geological processes of sedimentation of clastic and chemical sediments, beach environments, sinkhole formation, and ac- Teaching Earth Sciences: vol. 23, pt. 3 (1998) John Knill, the past-President of ESTA, earns his living as a freelance engineering geologist working in the Middle and Far East. After several years of visiting projects in jordan. his favourite desert island exposure was found on an assignment to look at the site for a brine evaporation pan. 141 The View from My Attic: Notes from your Prom ofion s Convenor Geoff Nicholson The tlt/eof this occasional piece isa.bit of whimsy- because there isn't one. A view that is.ldo have an attic or at feast a loft. but '/(ithout a view. The only thing yQU can see when you stc:tnd hunched at the top of the ladder is ESTA Stuff - the rag bag of paraphenaliaandephemeratrhat comprises the Earth ScienceTeachers' Association Promotional Material. Regular Conference visitors will already know the full extent of our' range of 'stuff but· not all our members are regular Conference goers. or indeed goers at all, and others may have missed the odd gem. This essay is then a cunning plan to swell the Associati9n's coffers by highHghting a few.items of stock that are new, less well kn9wn or particularly worthy of praise. I have just taken .deJivery of another Joad. of Buildin~ Stones postcards. I think these are wonderfullAmongthe cognoscenti of course they are popular hence the neEid t9 restock. They are produced by the DepartmentofGeologyatthe University 9fManchester ancl were designed as part of their distc:tncelearning cours~in Earth and Environmental Science. The set consistrs of 16 postcard sized· prints of photographs, natural size, of commonly used building and facing stones. If you read down the list you .will probably not recognise all that many. Penrith Sanclstone and Crinoidal Umes1:one will be familiar but who knows what Verde Issorie and Rapakivi arerOonotfret. On a ramble round the sh9ps, ban~ and building societies of Hull city centre I reckon I can. find most 9fth~mandyou should too in most towns. or at least cities. The Blue Pearl and Emerald Pearl are the iridescent larvikite (orsyenite I believe) typical of building society frontrs and Rapakivi or Baltic Brown is that granite with big rounded orthoclasecrystals. much beloved by Woolworth's to my recollection, and anyway pretty ubiquitous. These cards are a must for every rookie geology student who should be sent offwith a small flip-up ci1bul11of the pictures and a clipboard of appropriate questions to research their local commercial centre even if only at thE! "sedimentary. metamorphic origneous?"level. I imagine a student holding a card up to the '/(all - ..that's the one, noW for the hand lens -crystals or rounded grains?"''' The Portland limestone is particularly well reproduced; it almost feels right. Each card has a good description on the back .leaving plelity of writing space should you wish to use tnemas real postcards - although the Emerald Pearl should be sent to someone you are glad is not there ora geologist with a. sensebf humour (I know. they all have). Thesacards area snip at £3..50 a set and if you get a class set (10 or more) I will throw~nagrairt size sca/e with each pack to really set y~)Ur students up (but do remind me!). On theslIbiect of urban geology I have some copies of Peter Kennett's fittle.gem The General Cemetery. Sharrow, Sheffield. ··ldon't inclUde this in the general Promotions advert because it is of very focal interest but a boon to those who live in the Sheffield area (arguably the only one apart from the Peak District). The trail has been written with the general user in mind but includes some educational guidance. In the 14 A5 pages the guide gives 16 sites on a walk round the graveyard and points out rock types used on gravestones and weathering features. and includes how to get permiSSion to visit this fascinating cemetery, all for 751'. Teaching Earth Sciences: VOl. 23, pt. 3 (1998) Also. of local Interest or those planning ab?ll#aY<l,mqng the tomatoes there is Mlck cla Pomeraiand Ancf;yR.qbjf}son·~ clearly Written an iUustratoo gUiderheRQc;ks(JiJd>S<;~~ry~f Guernsey. There are 8 ttinerarieswithdetailed; /11aps.~~etches and very cOl11plete descriptiQns ()f th~I?"'a1:i?f1Sand:the'r geologkalsetting.This boo~letis. weft produ~f!d~ndincludes a useful glossary! 72· pagesla~dscape AS for £4.80•. Next the return of an. oldfavGurite. We used tostockTarr's SeIsmicity Map In 1990 and J find my aged copy .inv~lu~bf~.1 hope that its fall from stock was not because everyone had got one. Even so yours must be as well .used as mille so. I have obtained some more and anyway it is a good time to be .im.port.in.g. th.i.I1.I.gs. fr. . o. . m ..th.e. S.ta.te.s ..co. ns. ideringthe.... s.trength of the pound and all such as that (as they say in these parts). Strictly this is theWorfdSeismlcity Map prepared by the U. S. Geqlogical Survey originaUycompiled by Arthur C. Tarr. in 1973 so it does no:tcontaill the latest major earthq:uakesllut it is a. injneofu~efulinformation. ltdearly shqwsth~ linear nature of ear1:hquak~acti~ity~t thesimplestlevelle~ditlgonto to the idea of the. existence of phltes. TheBiggesteartn~akes, ofmagnitude greater thata~ arema.rked withdrdesand others: abo¥e4.S withdo~.~oitiseasy to ide:ntifywhere earthquakes are mostcomlllon and where the m()st<lestructive have been. Sh<lllowiQcusearthquakes. (lessthanIOkm) are shown in .red, In:-be~een in!jlue. and.deep focus. 'bel()w 300km,in blue enablillgs.tude:ntsto Jelentifythe Benioffzones; . The size is 120cmx 9Qcm Oust under 3ft)( 4ftfor; those who have not been metricated) and it will cost £5.QOforllrolled map. which is. less thal1 it was in 1990 so be sure to ten your physicist colleagues. Next fossils, well not real ones. These are the DivsrSityOfLife Fossil Replica Set proeluc~ by the Ope? Uni",ersity sinCe they toOk over Stewart .. Baldwin's fossil. reprodyction business. These are .a set of twelve replicas coveringawide· range of organisms, one plant arid ten animals, the twelfth!s a footprint. The set is beautifully. presented in a transparent pox and contains a fish and ashark~s tooth, a sea urchin. a sea-lily and a coral. a trilobite and a shrimp. an ammonite and.tW'o more teeth. one ·from an ichthyosaur the oth.er from a dinosaur. Meanwhile on land • a reptile footprint and a seed. fern complete thesst. Included for gUidance is a brief but useful overview of how the set .couldbe usedjn the .COIl text of Biology and Geography and how the organisms represented fit into the geological time scale. The sheet also includes skErt;ches of the spedmens and futl chapter .andverse.about their sources. The Primary Committee reckon this isideat forKS2 and a copy .of PEST 1- Fossils is avaifab~e free with each set (remind me if you want one!). It Is also an ideal starter set at all levels and cheap at £ 16.00. I am looking for the old Tuit catc:tlogueatthe moment since I need to get a Round . one.! After that I. must update the Promotions Advert for the Journal then I can view. the pigs flying past my attk. Geoff Nicholson Promotions 142 KEITH'S COLUMN The local newspaper in Monmouth is infamous for its lack of originality and content. It's hardly their fault as Monmouth is a classic stick-in-the-mud town where nothing significant ever happens. Council ludditesand SAGA commandos efficiently stamp out any sign of twentieth century encroachment. Monmouth has a website with a bulletin board. It is usually full of grumbling e-mails from teenagers who are bored to death with this town and its over-fifties stranglehold. Apart from a report on another spectacular pile-up on the bypass, readers tend to turn to the letters page for some excitement. Several under-occupied middle-class 'Victor Meldrews' regularly send incoherent ramblings to the paper. Thanks to the dubious Welsh Assembly referendum lastest offerings concern whether Monmouthshire is an English or Welsh. (By the way, I'm commander of the WMLA, the Welsh Marches liberation Army.) Anyway, the school staff room rolls about with laughter as we read these letters and when we think the fun is petering out we write something provocative to the paper to rekindle the debate. If that fails, a fake report of a hypermarket moving in to town usually gets the silly devils reaching for their pens! Recently, the spotlight moved to the twice-daily traffic jams caused by the schools. The girls' school, quite rightly, came in for a real panning. Their chaos envelopes over a mile of road and begins building up as early as 8. a.m. By comparison, we are real angels as most of our pupils catch a bus in. The girls invariably arrive in a motorised division of expensive fourwheel drives. I reckon they suck an oil field dry every year. I would like to see the driving age raised to nineteen. '0 Fun really starts at 8.25, when the buses start coming through. In the lead, often by up to 5 minutes, is a 25. seater from Newport. I've seen this thing on the dual carriageway and it is probably capable of supersonic flight and the ability to shatter windows as it breaks the sound barrier on the way out of the suburbs. The .driver obViously fancies a driving job with Richard Noble. This is not altogether surprising as some Newport drivers have a real 'in your face' attitude to driving. Many a user of the notorious Newport M4 motorway section has been passed by a rust perforated Triumph Acclaim doing 100 mph. and belching out black smoke. Elsewhere in the country, reports of such are likely to be treated as UFO sightings. Back to Monmouth..... The main group of thirteen 53 seaters treat the roa.d like a demolition derby track. Woe-betide anyone whose car is in the way! There are a couple of reasons for this; the drivers probably watch too many Mad Max films, and they are desperate to disgorge their cargoes of brawling, gesticulating, leering, ugly teenagers. As an ex-housemaster, I am all too aware of the aggravation boiling over on the back seat of every school bus. Sometimes it backfires on the perpetrator. A fifth form bully landed a well-aimed punch on the arm of a third former a few years back. He had forgotten that his victim had a plaster cast under his jacket sleeve and Teaching Earth Sciences: vol. 23, pt. 3 (1998) broke two fingers. Served him right. Another infamous incident involved a school rugby team on the way home from Tal,lOton. Somewhere near Filton. motorway drivers were 'entertained' by several hairy backs ides pressed against the rear window of a coach. Unfortunately, the idiots on the back seats have forgotten two. things, the telephone number of the bus company was emblazoned just inches below their window and the driver behind had a mobile phone. We were waiting for the culprits as the coach drew up at Monmouth: I love it when we outwit 'ern! Well, it's the school holi~ay now and the Monmouth citizens are enjoying the temporary peace while the bus drivers put their feet up and watch police chase videos. As I write, the A level results have finally arrived. Why does it take so long for them to emerge? Universities would much prefer students to have their results first and then apply for places afterwards. I stay well out of the way on results day after an incident a few years ago. While a majority of pupils were ecstatically downing the contents of several breweries at the local pubs there was one drunken individual, who had missed his university place by one grade. swaying about in Almshouse Street. He had decided. as many teenagers do these days, that the fault lay with the teacher rather than himself. I was treated to a torrent of abuse that was audible to everyone for hundreds of metres around. I was rescued by some· other sixth formers, who bundled him back into the nearest pub. I never saw him again. I need not have worried this year. We put 29 individuals through 'A' level physics and all but one passed, with a majority of grade 'A's and 'B's. The lone failure was a case of deliberate self-destruction. Actually, I am amazed that we do .so well because the entry .to sixth form physics is not selected and. despite appearances to the contrary, nor is entry to the school. Most of our charges will go off to do engineering courses although the odd one does choose geology. The bottom line is sponsorship and jobs. Geology doesn't really offer much of either. Just this afternoon I saw an ex-pupil from several years back: Jonathan Oavis works for Shlumberger in Stavanger.He reminded me o.f the boom-bust employment policy in petroleum geology. After adopting several universities with the intention of 'nurturing' potentially useful undergraduates, Shlumberger look likely to do a 'U' turn in the light of collapsing oil prices. Meanwhile. quite a few mud-loggers will be collecting their final pay cheques.. .for the time being. Although we are told that the pass-rate keeps rising there will always be those pupils whose Bves are shattered bydisappointing results. Many must think that their last chance has slipped them by but, having recently returned from Open University summer school, I am always reminded that there are other possibilities. 143 The OU has recently launched its new 'entry level' science What still makes. summer school a joy for me.is . the .. sheer enthusiasm of the students·. for learnin&. lam .tl'equently course, S I 03: Discovering Science. The course is very glossy and features the •latest .in educational technology.. It is, how- . amaled by their dedication and only wish. th~tmy.tJsuaJ charges were half as good. Howeverias rec,;ently.comrnented ever. very demandi.ng on staff and Students, and therewas no in a TES editorial. people are losing tOUch with~hat /Sreal and way I coulcf fit it in with my full time work. Nevertheless, I was what is. not. We. had the usu.albatch . ()ftl1a~cters who kindly included in the staffing of the summer school and had a claimed they could sense an aura emanatingf,.om~er1+\inrocks . chance to see SI 03 in action. (usually the moment they read that quartz waS apoosti),;yent). The summer school should have a balance of physics, chemis- This year they were joined by acoupleofwornenwhodaimed try, biofogyand earth science.enc;:apsulated in a number of they could feel the radiation from the radioaetive sources and that the man-made caesium sOutcefelt badcofTlpared to the multi-disciplinary activities. Inreafity,chemistry and biology equally active, but naturally occurring, uranium ore. have the lion's share. Earth science appears in two of the activities; a laboratory based one, whfch I helped With, and a "ve saved the besttHI last. I gave three tl1torials.ol) Newton's field activity. Theonlyproblem(and a perennial one at that) Laws .with the intentlpnof clearing up some of the I:t.onsense was the lack of detent geology In the Readingarea. I've surrounding them .. This seemed to work. buta.young. lady mentioned this before but this year the summer school tuto.rs approached me afterwards to ask .:lbout·.the·frictionJe~s . rnocoined a new term to describe the local terrain. M.A.M.B.A. tion ofrotke!:$ in space\ i,e. stop the engines and they keep country is not .snake infested grassland but an .ar;ronym for moving. She asked Whether all this wor'kedin 1l11pulliespace or MilesARdMilesofB-gg-rAII!Addthat one to your physical warp space. Ahead, warp factor nine. Make it so number one! geography notes. IneVitably, we fielded numerous questions abOl1t flint and its origins, as we do eVery year. Has aRyone yet Keith Moseley come up with a definite story about these tl1 ings or are we still Monmouth School to tel! elaborate tales about sponge spicules and other will-oMonmouth the-wisps? Please write if you know. . NPS3XP Te.achingEarth Sciences: VOl. 23, pt. 3 (1998) 144 News Geological Society of London A-level prizes Each year the Society awards a book prize to the highest scoring candidate in A-level geology in each examination board. This year the status of the prize will be upgraded to include a prize for the winning school and the winning candidate's teacher. In addition to offering The Geology of England and Wales or The Geology of Scotland to the winning candidate, the Society will be donating both books to the winning school, and offer one year's free Associate Membership to any winning candidate's teacher who is not already a member of the SOciety. Subduction starting off Portugal? In a short article in Episodes (March 1998, vol.21, No. I), the International Geoscience Newsmagazine of the International Union of Geological Sciences, A. Ribiero, of the University of Lisbon, suggests that a new subduction zone is being formed off the coast of Portugal - the start of the conversion of the eastern margin of the Atlantic Ocean from passive (Atlantic type) to active (Pacific type), with the creation of a new plate boundary. Three stages of the process can be observed along the zone: crustal faulting, buckling of the lithosphere,and whole lithosphere failure. The article actually poses the question 'What triggers subduction?' Recent thought, by Ribiero and others, is that the oceanic plate is 'soft~. due to the processes of seafloor metamorphism and serpentinization of the oceanic upper mantle. These allow the oceanic plate to deform internally, with a visco-plastiC rheology (in contrast to the elasto-plastic rheology of continental plates). Ribiero answers the question by saying that 'increasing deformation in a viscoplastic oceanic lithosphere . ultimately leads to its failure in the oldest and heaviest segments near passive continental margins; and this process is made easier by the presence of thick wedges of sediments above the transition from continental to oceanic lithosphere'. Minerals '98 In association with the Minerals '98, the British Geological Survey's publication Earthwise for June 1998 (Issue 12, £2.50) is a special issue devoted to the theme of Minerals. Yale College Wrexham Please note that the College has now shifted from its previous Gipsy Lane site to a a new town centre campus at Yale College Grove Park Road, Wrexham LLl2 7AA. Mary Anning and her Times: The Discovery of British Palaeontology, 1820·1850 A bicentennial celebration in honour of the first woman palaeontologist will take place at the Lyme RegiS Philpot Museum from June 2-4, 1999. Mary Anning was born at the end of the 18th Century and lived until the middle of the 19th. In those years, beginning as a young woman collecting fossils, she worked with the leading scientists of her day to assure Teaching Earth Sciences: vol. 23, pt. 3 (1998) England's place in the developing field of palaeontology. Nearly 150 years after her death, her life is still largely shrouded in mystery and misrepresentation;. her discoveries helped to form the foundations of palaeontology, and she was quite possibly the first profeSSional fossil collector, as well as being widely considered the first woman palaeontologist. The true importance of her work and contributions is not yet adequately recognised. This symposium aims tobdng together specialists in palaeontology, history and sociology of science to create a picture of Mary Anning's life, work, and times. Keynote lectures in the symposium will be given by Stephen Jay Gould; Hugh Torrens, an expert on Mary Anning and former president of the British Society for the History of Science; Sir Crispin Tickell; and John Fowles. A reception hosted by John Fowles is planned for symposium participants. A geolOgical walk in the environs of Lyme RegiS'S spectacular Mesozoic horizons is also planned. For those wishing to attend the symposium as participants or members of the audience, further information oncosts and available hOUSing in Lyme will be sent totho.se who answer the first circular. Details from the Lyme Regis Museum; Lyme Regis, Dorset, UK DT7 3QA; phone 01297-443370. Earth This magazine is definately closing, the August 1999 issue being the last - the publishers KalmbachPress have announced on their web site (www.earthmag~com). The August issue itself gives no hint of this, and indeed was a very good issue, with 78 pages. Articles included the origin of limbs, the flooding of the Black Sea by salt water from the Mediterranean, the deep structure of the San Andreas Fault, the invasion of America by Asian dinosaurs, and the quarries that supplied the building stones of Egypt and Rome. A Clue to the Origin of Life Astronomers using the Anglo-Australian Telescope have found a possible explanation for why life on earth almost exclusively uses left-handed amino acids and right-handed sugars as the building blocks of proteins and nucleic acids - a mystery that has puzzled scientists for t 50 years. They believe the asymmetry was imprinted in organic molecules in interstellar space before the formation of the Solar System. These molecules then found their way onto the Earth via the impacts of comets and meteorites to provide the starting material for the origin of life. This is revealed in a paper in the international journal Science by Dr Jeremy Bailey, from the Anglo-Australian Observatory, and his colleagues. In 1948, Louis Pasteur discovered that some molecules can exist in two mirror image forms, right-handed or left handed. In living organisms, molecules tend to be all one form. not a mixture of both. Amino acids for example, the building blocks of protein, are always left-handed. whereas· sugars (including deoxyribose, an important component of DNA) are always right-handed. When these molecules are synthesised in a laboratory, equal numbers of right and left are formed. The reason for the imbalance puzzled scientists for decades. 145 In 1930, scientists discovered away of destroying molecules of one-handedness, providing a partial solution to the problem. They used circularly polarised light. But this was only part of the story. When life began on earth, there was no source of circularly polarised light. Last year. scientists at Arizona Stat~ University discovered an excess of left-handed amino acids in the Murchison meteorite (The Murchison metorite fell .in 1969 near Murchison in Victoria, Australia and has been found to contain an extraordinary variety of organic molecules.) This remarkable discovery shows that the asymmetry alreadyexisted before life began on Earth, and may well have been present in the material from which the Solar System formed. DrBaileyand his colleagues used the Anglo-Australian Telescope at Siding Spring Mountain near Coonabarabran to shQW how the asymmetry might have been generated. "We detected circularly polarized light in a region of the Great Nebula in Orion called Orion Mol.ecular Cloud LWe know that new stars are being formed here, and we also know that organic molecules are present," Dr Bailey said. "This region may well be similar to the region in which our own solar system formed". The circularly polarized light in such a region could imprint a preferred handedl'less on any organic molecules in the region, including those in a. cloud beginning to collapse to form a star and its planets. "We know that ultraviolet circularly polarised light is needed to select handedness in molecules sueh as amino acids. hut unfortunately thick dust clouds prohibited observations. at these wavelengths," Dr BaiJey saki.. "So we made the observations at infrared wavelengths. .Our calculations however. show that circular polarisation is present at all wavelengths. from infrared to ultraviolet." he added. Many scientists believe that a preferred handedness in molecules must have been present in .order for the origin of life to be possible. These re.sults therefore suggest that the suitability of our planet for life may be as. much Cl consequence of the environment in which our solar s.ystem formed as of the local conditions on the early Earth. NOTE: Images supporting this release are available at Conference attende.es wilf have ample opportunity to examine some of the geology of Australia. Pra-conference .excurs.ions will include the Great Barrier Reef (3;.4 Days)! Uluru. Kakadu. and the Australian des~rt (5 days) .. During the conference one day field trips will take in the majE!stic blue mouhtalns.tne wonderful Sydney harbour. the golden beaches of Australia and Jenolan Caves focusing on the links betweengeosc;ience and tourism and modern processes in ancielltrocks. 'Field excursions fiJI/owing the conference wil1 jncludeRiversl~igh,a world renowned fosslllocality (4 days), and The Active Earth a field excursion to New Zealand (7 days), A group of international co-ordinators. is. reqUired to cover the USA, Canada. the UK. European COUntries. India~ Asia, African countries, and New Zealand, in terms ofspreadingth ta word of GeoSciEdlll. All volunteers for this role should contact the Conference Administration ASAP. For more information send your name, address. phone, fax and email details to Gary Lewis at glewis@agso.gov.au or geoaware@bigponc::!;com or through the mail to Geoscience Awareness, GPO Box 378, Canberra ACT 2601, AUSTRALIA The first and only Conference Circular is to be distributed world-wide in August/September 1998: cOntact the Conference Administration if you want to be on the mailing list. Careers For Geoscientists An American video, produced by the American GeQloglca.1 Institute: Careers for Gel,Jscientists introduces the breadth of scope of the geosciencesi induditlg atmosphere,. oceans~ and the solid-Earth. Through interviews with indi.vidual practicjng geoscientists discussing current projects, the nature ota career working in thegeQsciencesis revealed. A discussion of the opportunities and adventures of travel, wprkihg outdoors, and using state-of:"the-.art technology is presented through this rare glimpse into tile work-a-day wQrld of geoscientistS. Although produced in NTSC format (for the USA). it could be copied for use elsewhere. It can be ordered from: Robert Tiffey at the AmeriCan Geological Institute. ·Phone: 00.1-703379-2480 (from Britain. E-mail: rlt@agiweb.org TheAmerican price is $14.95 ,.(AGI. Member Society Memb~Price: $12.15). These prices inc\udeShipping and Handlfilg in the USA, and it can be ordered using a Visa or Mastercard. www.aao.gov.au/ptess/life.html lrdINTERNATIONAl., CONFERENCE ON GEOSCIENCE EDUCA'tION (GeoSdEdlll) "Dedicated to Teaching. and Learning" 16.- 20 January 2000. University of New South Wales. Sydney. Australia Features of this conference include: A modern active city venue and lots of. low cost on-campus modernaccommodation; Extended (4 page) abstracts; 15 minute oralpresenta~ dons; poster sessions; and. workshops on computer aided t«t(:hing and learning. innovations in teaching aids, how to run field exc;ursions. the electronic classroom, and school syllabuses. Sessions wit! be arranged to cater to all aspects of geoscience teaching including primary and secondary school, and tertiary level. Social· activities during conference wifl include a real Auzzie BBQ (with not a shrimp in sight) and some local cultural and historical attractions. Teaching Earth Sciences: vol. 23, pt. 3 (1998) Joint Nature Conservation CommIttee: Annual Report 97 ..98 The CountrySide Council for Wales. English Nature. Scottish Natural Heritage. and the Environment and Heritage Service (Northern Ireland) have just isSOedtheiranl'lual report. Under the heading of Earth Sciences, they state that they have been working on a system to disseminate Geological Conservation Review and earth science SSSI information to a wider audience. using c.omputer software. .The JNCChas also prepared a paper on the c.onservation issl,les associated with the international trade in fossil specimens - this will be sent to interested parties during the roming year•. Th.eGeological Conservation Review (GCR) has3lsQ madesigliificantprogress. This comprehensive list of sites of national importance for earth heritage conserva.tion. which will run to 42 volumes. is scheduled for completion by the end of the year>lOOO. This year has seen the publication of the 13th vollfme in the series - on fluvial geomorpholQgy- and writing contracts have been issued for alt but four of the remaining volumes. 146 The report is issued by the JNCC, Monkstone House, City Road, Peterborough PEI IJY, ISBN 1-86107-452-2. An educational literature database for the UK The British Education Index (BEl) is the authoritative index to the contents of UK education journals, published by the Brotherton Library at the University of Leeds. It is available in print, on CR-Rom, on-line and on the Internet. Education-line is an indexed, full text, electronic archive of conference and working papers, reports. policy and discussion documents and early research results in the field of education and training. It is freely available on on the World Wide Web at: www.leeds.ac.ukleducol INTERNET NEWS Note: as all Internet addresses start with: http://. we will not be including this in addresses. But it should be added when seeking sites. Chemistry If you want information on Chemistry, try the Italian Chemistry Site chimica.cjb.net It has, of course, .information in Italian, but also links to 3579 sites, ordered by: Directories, Search Engines, FTP Servers for Chemistry,. Gopher Servers for Chemistry, Data Sheets & Periodical Tables and various other Sites. Marine and Coastal Zone sites Ocean 98 is designed to promota activities related to the Year of the Ocean: www.ocean98.org SeaWebis a project designed to raise awareness about the ocean and the life within it. There is an on-line copy of Ocean Update newsletter, as well as background articles: www.seaweb.org The Great Barrier Reef Authority has a site at: www.gbrmpa.gov.au/-crcreef Coastal zone management sources are at: www.wantree.com.au/-kays/index.html Tsunami! .is a World-Wide Web site that has been developed to provide general information about tsunamis. Tsunamis are large water waves, typically generated by seismic activity, that have historically caused significant damage to coastal communities throughout the world. This site has been developed with a broad audience in mind; consequently. it contains extensive background information that is intended primarily for the general public. including information about the mechanisms of tsunami generation and propagation, the impact of tsunamis on humankind, and the Tsunami Warning System. This. site also contains more detailed information about recent tsunami events that will be of interest to tsunami and interdisciplinary researchers: h ttp:/Jwww.geophys. washington. edu/tsunami/ welcome.html The August issue of Earth lists the American Museum of Natural History's site on Black Smokers. This is based on current exploration of these hydrothermal vents, on the floor of the Pacific Ocean at the Juan de Fuca Ridge off the coasts of Washington and Oregon. The site includes teaching ideas based on this work. Teaching Earth Sciences: vo'. 23, pt. 3 (1998) www.amnhonline.org!expeditions/blacksmokers/ Another site listed is the US national site on Global Hydrology and Climate. This again includes material of use in teaching, and also gives details of a worldwide network - GLOBE- of students, parents, teachers and scientists studying the environment. www.ghcc.msfc.nasa.gov/ghcc_education.html Mars A site covering the Planet Mars: www.msss.com/education/edprog.html This lists· educational programmes and activities, with downloadable pictures. Palaeonto/ogia E/ectronica and Climate change Palaeonto/ogia Electronica, is a new venture: an electronic journal of paleontology published by Coquina Press. The principal objective of the journal is to provide instant, free and global access to the latest developments in paleontology and related fields: www.erdw.ethz.ch/-pe!aboutfm.htm It presents a limited selection of climate change web sites gleaned from government sources, advocacy groups, museums, and independent researchers. Topics range from web pages concerned with the potential impact of climate change, to those which examine the geological evidence ··of .previous climatic oscillations. Although not exhaustive. this annotated listing provides a reasonable cross-section of our current perception of climate change phenomena. Search engine Ask Jeeves is a very good search engine, which your Editor has found to work more quickly that most of the other engines, and with a good deal less jargon: www.askjeeves.com Solar Eclipse Information on next year's solar eclipse is available at umbra.gsfc.nasa.gov/eclipse/predictions Contrary to the British news media, you do not have to crowd into southern Cornwall to see this. The track of the total eclipse covers a band from south of Nova Scotia (iJ;l the Atlantic Ocean), across northern France and Germany to Turkey, Persia and peninsular India. 747 .REVIEWS Geology of the Hamilton district.·I.B. Patterson, AD. McAdam and. KAT. MacPherson. British· Geological Survey, 1998, 94pp. lSBNO~II-884533-0. £35. Geological Survey memoirs are a mine of information but they should iltuminate as well as inform. This volume· fulfils all of these .aims admirably in descrlbingthe varied geology of the Hamilton c:fistrictand placing it in th.ebroadercontext pf the evolution ohhe Midland Valley of Scotland from the SlIurian to the present day. The district covers the Scottish I: 50 000 sheet 23W and .extends from the fairly sparsely populated Hagshaw Hills in the south to towns induding Hamilton, MotherweU and East KHbddein the north: Theprosperrty of the area in the 19tband much of the 20th centuries owes much to. its geology, inparticu[ar to the coal, limestone and sedimentary iron ores and the now largely extinct Lanarkshire steeUndustrythatgrew from them. Opencast coal mining and the extraction of sands and gravels and hard rock aggregate are still important and. as the preface to the memo;r notes, dealing with the environm.ental legacy of the exploitation of geologicalresources requires an understanding of the geology on which they were founded. Chapter I provides an exemplary summary of the geological history of the district· illustrated by cploured maps/showing the physiography and simplified solid geology of the area.. Rathersubtle differences betweEan shades of green and Of purple in the Silurian inliers make the geological map a little difficult to .useat first sight. The suc;cessions in the lesmahagow and Hagshaw Hills inliers are described and compared in Chapter·2 and provide importantinsights into sedimentary basin development along the southem margin .of the Midland Valley during the . Silurian. Although not mentioned in .the memo!r, these inliers contain several Sites of Special Scientific Interest and are described by Rolfe in a field guide edited by j. D.Llilwson &D. S. Weedon (1992, Geological e¥cursions around Glasgow & Girvan. Geological SOciety of Glasgow). The sandstones, conglomeratesand,locaUy, volcanic rocks ohhe Lower Old Red Sandstone are described briefly JnChapter 3 followed by a lengthy chapter on the Carboniferous stratigraphy. The Hamilton district incorporates parts of three c()alfields. This, together with the other ~conomically important aspects of the Carboniferous rocks, meansthat there is a great deal of detailed information and historical stratigraphical terminology whichrnight have resulted in a rather turgid account ohhis part of the succession. Happily, the authors have provided a very c.lear acco\jnt illustrated by correlation charts. locality descriptions andcommef)ts on boreholes as appropriate. The chapterc()ndudes with an interpretation ofsedirnentation and vokanicactivityinthe wider context of the Midland Valley basin. . The biostratigraphy which forms· the basis of the correlation ofthe Carboniferous units is detaUed in Chapter 5. The district jncludes part ofthe only major Caledonian pluton in the Midland Valley, the Dis.tinkhorn Complex, and minprintrusions of Devonian, Carboniferous and Tertiary age. These intrusions and their petrography are described in Chapter 6. Chapter .7 presents a brief but illUminating account of the structural evolution of the district and its effects· on sedirnentationand magmatism close to the southern margin of the Midland Valley from the Silurian to the Carboniferous. An Teaching Earth Sciences: vo!. 23, pt. 3 (7998) extensive cover of gladaLandpost-glaclal segllllents blankets much. of the district and covers a: land· surface. wh 1chdevel· oped during the Tertlaryand e..rfy Quaternary.. The area lay in the region ofconfluence between the Highland and South· ern Upland ice sheets; and the effects of their epfsodes:01 waxing and waning (,l.ndth.efinaldegiacj(,l.tion of west central Scotland are described in Chapter 8. As with so many ofthe chapters, this account of the Quaternary stands as a useful case-studyiUustrath'lg how detailed observations, in . this in· stance of sedlments and landscape, can be used to interpret geological histori.es on a variety of scales. The body .ofthe memoir ends with short accounts of the economkgeotogy (Chapter 9), the re.sults of geophysical surveys which have been und(!rtaken in the district (Chapter I 0) andanextensiv~ reference list. One appendix lists data sources and another provides a written log ofa borehofein the upper Dinantian, the significance of which is not obvious. The cover of this excellent memoirshowspartof the front~ age of Chatelherau[t, a hunting lodge built of an attractive Upper Carboniferous sandstone in the northern part of the district by the 5th Duke of Hamilton in the early 18th Century. Shallow, stoop and room, .coal miningilithe latter part of the 19th Century resulted. In differentialsubsid.ence which affected parts of the buifding:· The. Dukesoft-l.a.milton were so keen to extract as Inuchcoal as possible that workings also exteryded tQo<='oseto· Hamilton. Pala~e, the largest country house in Scotland. and it had to be demolished in the 1920's.because 6hnining subsideflce. Thegeolo~of the Hamilton district not Qnlybroughtprosperity (for some), its careless exploitation also brought a.bol,lt ruin. AlanOwen Divislon of Earth Sciences University of Glasgow RegionalgeochefTtistry of north..east.fngland• .... British Geological Survey, K:eyworth, Nottipg/JamNG12 UJ<;., 1996. viii· + 100 .·pp.; . ' :250,OOOscate folded. mapo( solt<! . geology. Hardbound; ISBNO-8S2 72.255-9.£50.00.. . sa:;, Geochemical mapping was first in~roducedin t:h~ mineral exploration ind\j$try as a. to~IJor [?cati~gO'ltneral deposits. However. the publication of the Wolfsort G~ochemical Atlas of England and Wales in 197~saw thefirstge~emical maps which were produced fora rangE! of uses influding environ~ mental and pollution sturnes,agricultunfi1and. health issues etc. Since the pubtkation of that first attasmanyother:shilve beenprQducedinseveral countries. The current atlas is the eleventh in the series. of British GeOlogifat ~llrv~y~eochemical atlases .aimedat covering.th.e wholeof.Gl1eat.Brltain. This atlas covers the region of NE EnglandfromS4"t05S" Nand from the North Seacoastto 2"W. This is the fourth atlas in the series based on digitalgeoenemicaHmagery. While the majormedtum used .to.produce.themaps was stream· sedimelits(over 4000 samples), in the SE part of the area, underla.in by the Cretaceous Chalk.· there are fEaw streams so that soils were used (about 60.0). m.ac;ldition, stream water was analysed for uranium, fluoride and bicarbo- 148 nate together with acidity and conductivity. In this atlas there are 44 colour maps, 5 geochemical maps based on stream water data, 31 maps based on stream sediment and .soil data and Sthree-component images each based on data for 3 elements in stream sediments and soils. The 3-component images were generated by assigning each of the 3 elements one of the colours, red, green and blue. The. solid geology of this region is dominated by sedimentary rocks ranging from Carboniferous to Cretaceous in age, with the Carboniferous rocks outcropping in the west and underlying the whole of the area. Superficial Quaternary deposits of glacial, glaciofluvial, aeolian and lacustrine origin occur over much of the area. Within the area covered by this atfas there has been extensive mineral extraction ranging through coal, iron ore, base metals, baryte, f1uorite and evaporite minerals. Additionally, within parts of the area there has been major industrial and urban development. Many of the geochemical maps for the differing elements reflect the major anthropogenic influences in the area,particularly mineral extraction.· Thus the stream. water map for fluoride shows highest values in the old f1uorite mining areas, while the stream sediment/soil maps for barium, lead and zinc amongst .others reflect. the strong influence of abandoned baryte and base metal mine sites. Elements such as beryllium, cobalt and vanadium, which are enriched in coal, and those such as gallium and potassium, in the associated shales, are generaliyelevated over the Coal Measures but their distributionis also strongly influenced by the dispersal of colliery spoil. The distribution· of elements such as cobalt, nickel, tin and vanadium is strongly influenced by urban and industrial contamination, while Cr, in particular, is extremely high in stream sediment samples in the Darlington - Teeside area around a chromite processing plant. Despite the strong influence of anthropogenic activities some element distribution maps strongly reflect variations inlithology. Thus the highest concentrations of boron occur over the Triassic bedrocks and the overlying Quaternary depoSits as well as overJurassic and Quaternary mudstones. The magnesium map picks out the Permo-Triassic sequence of the area while Ca and SI' tend to delineate the limestone and carbonate-rich rocks of the area. Overall this is perhaps the most interesting of the British Geological Survey regional atlases produced to date. Given that the area covered is one where there has been a long history of a wide range of mineral extraction, industrial development and urbanization, it is not surprising that this is reflected in many of the geochemical maps. However, what perhaps is more surprising is that the strong influence of base lithology. is· also very apparent. For these· reasons I would suggest that this atfas will be of value to those interested in environmental, geological and geochemical teaching. This Atfas, in common with its predecessors is excellently produced, and the relatively low cost of £50 would seem to make it a very attractive purchase. Ron Fuge I~stitute of Geography and Earth Sciences University of Wales Aberystwyth Ceredigion SY23 30B Teaching Earth Sciences: VD/. 23, pt. 3 (/998) Groundwater - our hidden asset. Compiled by RA Downing on behalfof the UK Groundwater Forum. British Geological Survey, 1998. 61 pp., ill (col). ISBN 0-85272-304-0) £6.50. This book is a layman's guide to groundwater published as part of the British Geological Survey's Earthwise Publication Series. It has been compiled by. Dick Downing on behalf of the UK Groundwater Forum, which is a lobbying group for groundwater formed by major stakeholdersto promote an understanding of groundwater issues. It is designed to be of interest to politicians, administrators andenvironmentalists as well as engineers and scientists. involved in water affairs and to students of science subjects at Key Stage 4 and above. The book. is concise and lavishly illustrated in colour. It discusses how and where groundwater occurs, how it is used and how it is managed. Traditionally it was of very good quality and threats· to it from agriculture and industry are explained. The fact that groundwater maintains river flows ahd preserves wetlands during the drier summer months is emphaSised. According to the introduction the book attempts to demystify the subject of groundwa~er - does it achieve this aim? It is written at two levels. A general account printed in black is provided under each main heading and can be read as a continuous text. This is supplemented by more detailed reviews of important issues, together with case studies Which are printed in blue. The general text is well written and. will be extremely useful to teachers of earth science asa cheap and easy to read text for students at GCSE and A-level as well as a text for first year university students. However, there are some things which could have been done better. The diagrams generally have too much colour and for example the complex colour scheme used toaccen~uate the outline ofthe UK in Figures on pages 7 and 34 is confusing to say the least. On page Sitisdaimed that hydraulic conductivity has units of velocity. Hydraulic conductivity (K) has unitS of volume per time per area and hydrogeologists usually express it in terms of cubic metres per day per square metre. This reduces to metres per day but does not mean that K has units of velOcity. Despite these problems the book will be a valuable resource to all teachers of earth science both at schools and universities. At a cost of £6.50· it should be in every school and university library. J.O. Mather Royal Holloway College University of London 1:50,000 scale Sheet 7 The Causeway CoastfSoUd Geology] Exploring the landscape and rocks. Geological Survey of Northern Ireland, published by the British GeolOgical Survey, Keyworth. ISBN 0-7518-3213-8 (flat); 0-75/8-3213-6 (folded and cased). £5.00. The British Isles is. fortunate in the variety of its geo\ogy, and in its excellence: particularly in coastal areas there are dramatic examples of many facets of geology. Land's End. the Lizard. Weymouth to Swanage, Siccar Point, the Pembrokeshire Coast, South Stack all come to mind. The area of the Giant's Causeway is one of· the most striking and important. The region has MesozoiC sedimentary rocks, and a· variety of 149 Tertiary igneous rocks of wllich the .Giant's Causeway itself it the most famous. The area also has a historical daitnto fame, as in the early 19th century the Neptunists claimed that the dolerite of the Ramore Head Sill in Portrush contained ammonites: proof of its aqueous origin. The Causeway area was covered in the 1960's, in a sheet still available from the BGS at £9,95, solid or drift, but this is a revised third edition. Comparison of the two maps shows that revision is mainly confined to redr:afting. the actual lines on the map being the same. One curious reviSion, however, is that in the extreme south-east of the 1968 sheet a small area shown as Dalr:adian.has now become Triassic. Redrafting, and en· largementto the I :50,000 scale, has resulted in a map whieh is far easier to comprehend. The format· of this map is a new venture: it combines a standard geological map, with horizontal and vertical sections, with explanatory matter written for thenon-geologist: Thi.s includes a section on how to read the map. photographs, more explanatory keys, an 1800 word description of the geology, with block diagrams, and summaries in German and French. The description of the geology - headed "Landscapes from stone" - is a well written account which is easily understandable by the non-geologist. It makes .a point of setting the geolo~ in a world context, l?y introducing the concepts of geo{ogkal plates. continental drift and climate changes. Indeed one of the iIIu~tratjons is·ofthe eruption of Kr:afla in Iceland in 19S0.The text starts with a brief mention of the legend of Finn McCool, the giant who is supposed to have made the Causeway. in an attempt to fight his. Scottish rival, and then introduces the concept of plate tectonics, to set the scene. The oldest rocks exposed at the surface are the early Jurassic Waterloo Mudstones (long known here as the Lias Clays), unconformably f0110wed by the ·Iate Cretaceous Hibernian Greensands and Chalk (the Ulster White Limestone Formation). The bulk of the area is of course formed of the Tertiary igneous rocks: the basalt lava flows, agglomerates. and tuffs. intrusive plugs, sills and dykes~1 was surprised that the term "plug" (the Sendoo Plug) was used without more explanation (that it was the magma which cooled in the cylindrical feeder pipe to a volcano). Tertiary faulting is not mentioned in the text, but the Portbraddan Fault at Sallintoy is a good example (this area makes a very good student exercise in mapping). Finally, after the last glaciation, wave-cut platforms were cut: one is mentioned as being present at the White Rocks (locality 2 and photograph): it is not obvioos. There a few errors in the text, though none that cause serious misconceptions. The plates are described as resting on the mantle - as though they are simply crust - and the mantle is described as being "treaclelike". The plates are said to move because the mantle is hot and viscous. Igneous sills spread along "lines" of weakness. One m1nor complaint is that this text is set over a ghostly image of the "the organ". This isan example of a modem disease which is all too widespread: the image makes the text more difficult to read, and is itself too faint and interrupted by text and photographs to be understood. One is simply infuriated at what seems to be mere gimmickry. The block diagrams, with explanatory notes, attempt to show the history of the Giant's Causeway itself. However, they are misleading in two respects. Firstly, the middl~ one shows a small volcano with slopes of up to 70 degrees: almost a cartoon volcano. Secondly, the diagrams showing the origin of Causeway columns are quite incorrect. As described in the text, and shown both on the map and in the horizontal section, during. the early part of the Interhasaltic (Port na Spaniagh Member) a river valley was cut into the surface of the Lower Basalts. This is indicated on the section as being about 150 Teaching Earth Sciences: vol. 23, pt. 3 (1998) metres deep at the Causeway. The first flow of th~ Causeway .Tholeitic Member was. then ponded iothe valtey, and cooled slowly to form the columns of ~e Cause ·itself {and the inclined columns in the old cliff to the However, the middle diagram shows no erosion of the lower basalti, only a gentle warping which appears to be making th.1! valley. Finally the upper diagram shows a rather improb<iblearrayof columns at this point, which appear to project up. through "a second ancient soil horaon". I am. not. clear whether this refers to the the BaJlylagan Member,whkhls not exposed at the Causeway, and is certainly not the weathered top of the Causeway Flow, ortQ the top of the Causeway flow itself. Note that. the Causeway Tholeitic Member. is .about 120 metres thick. to which should be added~he J 50 metres of the valley at the Causew'!Y. and consists ofa number of flows (tw.o of which can be seen in the photograph ofthe diffsabove Port Noffer). It is unfortunate that. the diagrams - at the heart of the map are so misleading, because the rest of the map. diagrams, photographs and text are excellent. There is na doubt that the interested layman will find that this will answer many questions about the area, about geology in general, and may lead to a further interest in the subject. It is good to see that the price is only £5~this should attract sales (should every household in Portrush have a copYn. presumably at the ex~ pense of sales of the second edition maps. I wquld hope .that this format could be copied for some of the other areas mentioned above. Indeed would this format increase sales of all maps? Denis Bates tnstitute of Geography and Earth Sciences University of Wales, Aberystwyth Whisky on the Rocks - Origins of the Water of Life. Stephen and juUeCribb, with illustrations by Richard Bell. British Geo/ogicaISurvey;.l6,50. ISBN 0-85272-290-7. I was asked a few weeks ago to review this smaU paperback, and decided not only to do that, but also to road test it on what turned out to be a very wet few weeks in Scotland in July 1998. Thus, on a: da~p and midgey evening I settled into a comfy armchair in the Morar Hotel, Talisker in hand, and pulled Whisky on the Rocks from my rucksack. Whisky on the Rocks is an informativeguide to tbe whisky and geology ofScotiand,. which starts put by describing the process of :whisky production. Then, for each. distiUery, the relationship between the geology of the area, the water ~.upply and the final product is described. The Bushmills distiUeryJn Antrim is also included. [Editor's note: this of course produces a'supe. rior product to whisky, i.e. w.hiskey.B!Jshmilts is orithe Giants Causeway geological map, the subject ofanother review in this issue.] The authors assume you have no knowledge of geotogy,and divide Scotland into a series of geological areas ol')the.basis~f major structures, giving an outline of the overalt.evorution of each area. They then take.the plunge and dest:ribe each area in detail - the Argyll Islands, the Grampi~ Highlallcfs; the Far North, the Deep South and the.Witd Wes~For e.3ch ar;ea,for example Islay as part of the Argyllfslands section whioh merits 10 pages. the geology is reviewed on a.regioflal scale, and more local detail is provided along with the specifics of each distillery and some notes as to the character of each distillery's product. For a book of limited size, there is a wealth of detail on not only the geology, but on the local area and the history of each 150 distillerY. In addition, the book is lavishly illustrated, with over a hundred attractive ink and water-colour paintings. These include sketches of distilleries, views, maps - both geological and location, geological cross sections plus a few satellite images of each area. An index and a small geological glossary at the back complete the story. To this end, this book provides the geologist with an acc;ouht of the location and basic geology and hydrology of each distillery; for the whisky drinker it provides a readable and basic account of the g!ilology of Scotland. It should thus widen the appreciation of how important geology is in governing something as seemingly far removed as distilling. Sadly, there are two things I have to have a minor gripe about. The water-colour paintings are very attractive and beautifully capture the atmosphere of the Scottish scenery and of the distilleries ~llongto be able to paint like this: The illustrations of. the fossils. and the fish of the Far North, too. look fine. Unfortunately however. the sketches of some of the rocks require more thana little imagination to interpret. The stromatolites of Bunnahabhainn don't really look like .that (page 13) and the samples of Insch Gabbro (page 29) could be mistaken for a host of other rock types - from the sketch my first reaction was the pseudoleucite syenite of Loch Borolan and a colleague suggested an amygdaloidal or porphyritic lava. Sketches like this ire not informative. and will do nothing to help non-geologists identify rocks as they wander the hills in search of a. dram. My second problem concerns the final productionofthe book. Driving down the A9 from Dalwhinnie. it was impossible to follow from the map (straddling pages 24 and 25) whichdjstiUeries were flashing past. The binding was so tight. that we appeared to be passing BLAIR L. CHRY and ABY (Blair Athol, Pitlochry and Aberfeldy if you were wondering). A great section of this map was lost in the crease between pages. and the· same was true for virtually every other map printed across two pages - a most irritating fault which could have been remedied easily in production. Whisky on the Rocks is Widely available in Scotland and was spotted adorning shelves in bookshops and Tourist Information offices throughout the north-west highlands and islands. It is an entertainingread, and an informative one. 1f you enjoy your whisky•. it wilt provide you.with a wealth of information on how that water of life· comes about. What is· more, you do not need t6be a geologist to learn from this book, although as a geologist it will give you food for thought. When you consider Whisky on the Rocks is about the price of two distillery toUrs, or three malts in a bar, or a quarter the price of a bottle, it is good value and will long outlast its liquid hamesake.Granted, it may not smell or taste as good, but it wont leave you with a headache in the morning! Nicholas J.G. Pearce Institute of Geography and Earth Sciences University of Wales Aberystwyth SY23 3DB Helping Eartli Sciences Students to Develop Key Skills: A Portfolio of Curriculum Exercises. The UK Earth Sciences Personal and Career Development Network.. Available from: Dr Neil Thomas, Scho01 of Geological Sciences, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey KT I 2E£ (e-mail n.thomas@kingston.ac.uk) or Dr Helen King, School of Ocean and Earth Science, Southampton Oceanography Centre, European Way, Southampton SO 14 3ZH (e-mail H.King@soc.soton.ac.uk). £20. No.ISBNnumber. Is there any earth sciences department in the country that Teaching Earth Sciences: vol. 23, pt. 3 (1998) does not now incorporate careers, communication skills, team skills and the various other key skills (whatever happened to transferableskillsl}in its curriculum? I suspect not. The Enterprise in Higher Education programme has been an undoubted success. Students leaving university. now not only have a subject-specific degree, but also have had the opportunity to develop those skUls most desired by their prospective employers. Degree courses have been modified to incorporate exciting new teaching and <j.ssessment methods. Both staff and students have been stimulated and have benefited. On this basis, this new portfolio of earth sciences-based key skills activities is most likely to be used to tweak existing departmental programmes. It is certainly not, as it would have been perhaps a decade ago, a revolutionary. proselytising document. The Portfolio is divided into four main .sections: Induction, T I,ltorial Exercises, Long Exercises and Career Management. Each section begins with an introduction and is followed by a series of exercises, each with tutors' notes explaining the objectives of the exercise, the time that should be allowf!dfor its completion, methods of assessment (where appropriate) and advice on stimulating reflection/discussion by students during feedback sessions. If you've been involved in developing or delivering key skills-based material, many of .the exercises wilL seem familiar. However, with more than 40 ex,ercises in the portfolio, it's very likely that you'll find something new here to use or to adapt. Many of the exercise$ are suitable for use in tutorials, whilst others are conSiderably longer, the excellent 'Mineral Exploration and Exploitation' exercise, for example, haVing been designed to runover eight weeks. If your skills course contains formal assessment, some of the schemes presented in the portfolio may prove very useful. I was particularly impressed by the 'Seminar Presenta~ tion Feedback and Rating Form' and will certainly be using it in my tutorials. The Career Management section is very good indeed and for any department yet to incorporate careers within its undergraduate course this section could form thenudeus to an excellent second year short course or major component c>f a skills-based unit. For those having such courses alreadyestablished, there may be some fresh i~eas for exercises on action planning (always a tricky topic to teach), CVs, interviews, etc. The portfoliq ends with a single-page summary sheet, a list of references and a (much too) short bibliography. In the foreword to the portfolio, Professor Michael Brooks, the Geological Society'S Education and Training Officer, states: 'As the·national professional body forgeosdence,·the Geological SOciety... commends the portfolio to the HE geoscience community. The Society expects the use of these Network resources to contribute to the enhancemeht of quality of HE geoscience teaching programmes in the UK.ltalsoexpects that their use will feature in many ofthe geoscience degree cOurses that it accredits.' Of this,quite rightly, there can be little doubt. Having said this, how could the portfolio be improved in future editions? I. 2. Remove the square smudge from the bottom left or right corner of most· of the pages. Whilst for me evoking pleasant memories of a childhood visit to the Tate Gallery, the smudge otherwise detracts and distrac~ on every page that it appears. Add page numbers. This is important for two reasons. First, I'm sure that users are going to wish to remove (ahd then replace) pages from the portfolio from time to time. 151 Second, therrngflle has a tendency to bors.t open (a habit that wtll presomablyincrease with ose)~ Although some pages can ,be replaced easily enough byreco",rse to the COt\tents page; considerabtetime would be saved simply by adding pagenombers; 3, Increase the font size. of the text, shorten paragraphs and indent new paragraphs. The portfolio does not alwa.ys make easy reading (see 7 belowl. This is not helped by.the small font size and overabundance of dense blocks of text. Given that only one side of each pi.ece of p<iper. is used (why is this?), the reaSOn cannot be to save space. 4. In Case Study 3 in ·the Degree Management Case Studies remove:the suggestion that alcohoUs drunk at lunchtimes On field trips: 'He enjoyed going on fieldwork because it was a chance to have a good day out and a pub lunch'. S. Remove any text that might be construed as sexist. In the exercise 'Writing a Popular Science Report' it is suggested that each student should 'Ask your friends outside the subject, non-scientlsts,your mum (especialty if she is not a scientist) and other members of your family.' 6. Include all relevant materlal in the portfolio. In the 'Teamworking exercises' section one is referred to an assessment strategy 'given on the UK Geoscience Education Consortium web site'. Why couldn't this assessment strategy have been included in· the text? Similarly, on the second page of the 'Structured Series of Tutorials' SeC.tion and in the exercise 'Team analYSis and oral presentation' one is instructed to <see Guidelines forGiVing a Truly Terrible Talk'. 7. Where is one to find these? Presumably in The Complete Student by D. Saunders listed as a reference at the bottom of the page, but this is not made dear and is not very helpful if you don't have Saunders' book to hand. Make sure that in a text which emphaSises the importance of written communication skins that these are' demonstrated to a high level within the portfolio. The portfolio getS off to a bad start in thiS respect: 'Modern employers require graduates to have evidence (curriculum-based and extra curricula) of well-developed key skllls and are able to take control of their own career development' (second page of 'Introduction'). Similarly, in the 'Background' section to the exercise 'Kingston OU' one reads: 'Time is of the essence to Kingston Oil because the company wants to get into thebuJlding within a week because the delay is losing money.' This IS on one of the sheetS designed to be given to students! Elsewhere, the portfolio is not always a model of clarity and I found mySelf having to reread many sentences to grasp their meaning. There are also innumerable examples of missing or misplaced punctuation marks and other min.or typographical and grammatical misdemeanours. I would like to have a pound for every sentence in the portfoliO to which I would insert the word 'that'. 'Extra-curricular' is misspelt throughout as 'extra curricula'and I was very surprised to see 'practice' used as a verb in the exercises 'Geological Puzzles', 'Team Analysis and Oral Pres.entation', '~ingstoh Oil', 'Geology and Man', 'Mineral Exploration and Exploitation' and 'Seminar Presentati.on'. Finally; and· most remarkably, as the heading to the foreword written by Professor Brooks exhorting us to use this portfolio, 'foreword' is spelt 'foreward'! Were this portfolio the academic work of a student it would have been returned With a fair sprinkling of red pen annotations.Were it part of the application material for a job requiring good written communication skills the apparent Teaching Earth Sciences: vol. 23, pt. 3 (1998) absence of careful proof reading could well have cost applicant their chance of an interview! t~ Oavid K. Loydell ' . . . . .. School of Earth. EnVironmental and Physical ScienCE University ofP01'tsm.outh Burnaby BuildiQg Burnaby Road Portsmo.uth PO I 3QL United Kingdom Minerals Yearbook 1997, Statistical dat to 1996• . Compiled byJAHi/Jierand I), E. Highfey 1998. Briti~ Geological Survey, 87pp. £.35 softback. This is the latest in the annual publication of U.K. minera statistics and. deals With all. aspects of mineral production an consumption within the UK both on a national and region basis. It is in essence a c:ompilationof tabtes, graphs and maf relating for the most part to the previous 10 years thou~ sOinerelate to a longer' timescale with a few show.ing th changes over a,[QO year period. In addition there areovel view summaries commenting on recent actMty and trends. The first section is an overview of minerals in the Nation Economy and this is an up-to-date review and comment eve though the actual statistics presented are two~years old.. Th time-Jag is inevitable since BGS draws heavily on the statiSti< produced by indiv:idual·bodies·within the minerals industriE and it takes time.toactumulate and produce the. data. In th context the overview is invaluable since some trends show by the statistics up to 1996 may be showing. signs of chan~ and comments. on these trends and on government poliCy ar made. This section shows the staggering contribution made to th British Economy by the minerals industry, some £18.06 million or 2.8% of G[)P, but 1()]% of the GDP of all produc tion industries in 1996 . However, there is a big dark c.lo.ud 0 thehorizon~for the Extractive Industries in the form ofa aggregate or quarrymgtax currently under consideration t the Chancellor of the Exchequer. This could render mal1 operations (including opencast coal) less . competitive wit other options sl,lch ~s imports of crushed rock <)r secondar aggregates as proposed by the Verney Commlssion though th quality of secondary aggregates is inferior to primary materia Two ofthe most valuable tables areproduced.in this sectiOI namely the apprOXimate value of minerals produced in th United Kingdom I98W 1996 and lhlited Kingdomproductio of minerals 1991-1997. These show the dominant roleplaye py the fuels, now mainly oil and gas; in terms ..of value. but i terms of quantity the aggregates·indlJStryisth~·I<\rgest sectol However, a revealing factor shown by the.sefi~res is th significant size oLsome of the less obvious sectors of th industry. The day industry generated' in theord~r. of £30 million of wealth.in each of the last 5 years, though the bulk ( this was earned by the production of China Clay. Potas extraction is. valued at £93 million, Silica Sand at£S7miniol Gypsum and Anhydriteat £22 milliooanti Rock Sa:lta stagger ing £ Ias million for 1996. There i~ no <other source. ( information in Britain where such data' can be so readil assimilated and the indusion of pie graphs to show thestati! tics in diagram form improves the presentation of data. The volume then addresses the Energy. Minerals with a excellent review of the current state of the industry an 15~ explorat1on activity. The graph of United Kingdom production and consumption of primary fuels 1950- 1996 summarises a lot of the statistics shown in the tables and reveals some very interesting trends in the industry. Britain's total primary fuel consumption has become fairly constant since the mid I970s after continued increase since 1950. Since 1980 total primary fuel production has been in excess of consumption and the latest trend shows the gap to be widening. Since the late I950s the production of coal has been in steady decline, and interestingly the miners' strike of 1984, although showing a drop of over 50% of production in relation to 1983, has had no lasting effect on the overall trend. 1992 saw Natural Gas production overtake coal and if the downward trend continues the contribution of coal to the nation's energy supply will be no more than that of Hydro and Nuclear electricity production.Economists often state that the figures of a few years in isolation· can be mislea.ding and this is certainly true if one looks at the graph of oil production The figures for 1988 and 1989 showed a steep drop after a peak of about 140 mt oil in 1986/1987 and .at that time it would have been very easy to state that oil production in the N.Sea had passed its peak. However, the early 1990s showed a recovery with the 1996 productionabQve the peak of 1986/1987. One should always look for reasons for these changes and the gap between the exhaustion of old fields before production was achieved from developing·· fields can easily account for these· swings in production. The success story of recent years must be Natural Gas which doubled in production from 1990-1996. Much can be learned from these tables and graphs and when the map of the hydrocarbon energy resources is also viewed it adds to the overall picture. The largest section of the book is devoted to the Construction and Industrial Minerals with a similar pattern to the other sections, starting· with an overview. The tables are more detailed than those in other sections in that the production of construction materials as well as shOWing the national picture also show the respective role of the regions. For example the E. Midlands, the South West Scotland and Wales are the dominant producers of crushed rock aggregate whereas the South East is by far the largest producer of sand and gravel. What is obvious from the graphs is the steady state of the industry for the first half of this century and the post-war demand for construction raw materials started a sharp· rise which continued until the I970s after which rapid fluctuations in the order of 10s of millions of tonnes per annum are demonstrated. The graphs and in more detail the tables, show the relative importance of Land and Marine production of sand and gravel; the relative importance of sandstone, igneous rock and limestone (by. far the largest); and also the end use of their materials. The book concludes with a very short section on metals and a section on commodities and trade which brings· out our dependence on other countries for our metals and many specialist minerals. As it stands it is a valuable reference book but a few additional features would improve it. For example maps similar to that showing the oil and gas fields of the N. Sea for many of the other minerals would be useful including offshore sands and gravels. Admittedly it would not be possible to show individual quarries· on a map of that scale but dominant areas of production could be shown. The main draw-back of this book for anyone considering Teaching Earth Sciences: vol. 23, pt. 3 (/998) purchase is its very short shelf life. Within 10 months of my writing this review the next edition will be available with more up-to-date figures. This must be a deterrent for individuals and even for some librar.iesthat operate on a small budget. Teachers of geology will find this to be of use and arecommendation to the school or local public library for the purchase of a reference copy couldbe a way forward. Perhaps a copy now and an up-dated version in a few years time ma.y be adequate. There is a wealth of data in this book and much use could be made of it outside geology, such as geography, economics and of course. statistics. D.E. Roberts Staffordshire University College Road Stoke-on-Trent World Mineral Statistics 1992-96 Production; Exports; Imports. Compiled by LE Stockwelland others. British Geological Survey, f998. 296p. £ 80. This book is exactly what its title states -280 pages of statistical tables with no an.alysis or appraisal of the data. Some 70 commodities are listed, the major ones in alphabetical order with some 12 of the others. though not al~ areo! minor importance since the list includes uranium, at the end. Also included are world maps showing the production of 10 commodities and graphs of world production 1981-96 of 20 commodities. The statistical tables are. for the five years from 1992..96 and all follow a similar format for which the tables for Copper can serve as an example: mine production from 46 countries; smelter production from 38.Countries; productionofrefined copper for 43 countries; exportS ofcopper (4 pages); imports of Copper (4 pages). Not every commodity has the same list of tables, diamonds for example being listed as exports and imports only whereas iron has additional 'tables on steel and . ferro-alloys. The book is comprehenSive and contains a wealth of data, but it is raw data and to gain some meaning out of .trends in production and consumption one really needs a good knowledge of the international minerals industry.. The maps do not help much other than to show at a glance that South Africa is the largest producer of gold and that China is the . largest producer of iron ore. Russia is shown as thelargElst producer of natural gas but the country is so large in comparison with most others and includes shield areas as well as gas producing areas that one has no idea from the map where production is taking place. It is not5urprising that those countries with large surface areas dominate the rankings - they have more land available. . If one had the time to produce graphs important pictures would emerge. Take the mining production of gold as an example: South Africa dominates but shows adrop of almost 127 tonnes from 619 - 492 tonnes gold metal between 1993 and 1996; the USA is more or less steady, at about 32.0-330 tonnes as is Canada (147-1 66 tonnes) with small annual changes but Australia records an increase of 46 tonnes to approx. 160 tonnes. Russian production dropped from 150 tonnes to 127 tonnes. Figures are shown for 80. countries from the very small producers to the giants listed above. However, it is only those with an insight into the gold mining industry who realise the significance of the changes and trends shown .. The book would be of more value if some comment on the causes of the changes listed had been made and some pointers for the future 153 given. There. are other publications available w~kh give statistical datcl,on mineral and metal production though it would be difficult to find it all in one volume. The United States Bureau of· Mines •. Mineral Commodity· Surveys. give a we;rlth of data together with an interpre$tion of the current situation but many of these are very much out of date now and they are not in one volume. The Minerals.Handbook.by Phillp Crowson covers much the same ground as does WprfdMlnerals Statistics but that has additional graphs showing annual production of metals as well as prices over the same period in constant US dollars: However. the data is not as extensive or as compre.,. hensive as World Mineral Statistics; Those who require some insi~t and guidance through the tables would probably find the other publications to be of more use even If a little .dated and less comprehensive. It is unlikely that this publication will be of great interest to teachers of geology, particularly at a price of £80. It also has a shoft period of value since. it is already 2 years out of date which is inevitable in view of the time required to compile and publish the data. Furthermore. it will be up-dated in a year or so time. Its main readership must be commodIty dealers metals traders and those Who specialise in this field. It is a necessary text for the libraries of mining companies and other related industries but it would be difficult to justify the expense in the schools environment. D.E.. R,oberts Stafforctshire University College Road Stoke-on-Trent Horse. Forelimb Evolution Model. Available from Pangea UK, 185 Oxford Road, Ca/ne, Wiltshire SNII BAL, £34.70 (incl. delivery plus VAT.). The rise (literally!) of horses from the Eocene to the Recent is one of the most· fascinating of all evolutionary stories and is probably taught in a very large number ofschools and high~ education establisnments·throughout tQe 'HQrld; ·Yery feW.l these establishments, I imagine, have acOlllplectt; set of skeIet remains of all the taxa, and therefore pl\1stet.castscan repn sent an invaluable teaching aid. . Five taxa are represented in the set: Hyract.rtlierium.Me$ohippu Anchitherium, Merychippus and £.quus .. Of these,·Aotfiithffrlum often depicted as a Mio(:ene evolutionary sfd~line andperhaF the set. would have been moreuseful.witn thlsgj!nus replaCE by Parahippus or PliQhiPPus (or both). Art the casts are made ( a material described as high impact moulding plaster, rh £qvus model arrived. in PortsmoUth ins~vera/.. pieces, whic hi~[ights the problem with all large plaster casts: they ar easily broken. The casts, which . are of good quality, show the forelimb i different states of completeness: the Mesohipptts an Anchitherium casts possess phalanges. metacarpals and carpal whilst the other threemodets possess phalanges and (incorT plate) metacarpals onJy. The casts are acc90'lpanied .by diagram illustrating the foreUmbs·and the age of the taxa frOI which they originate, and a sheet of text .entftfedTeachin Notes'. In the diagram, none of the generic orspecifj~ names italicised. specific names are given an initial capital, AnthitheriUl is misspelt,'T odar~ is used instead cif Recent and Metychippt is shown as oflate Pliocene age (it is a Mfocene genus). Onth Teaching Notes, againgen~ric namt}sare notjtaticised, meal urements are given only in i(lches. Mesobippus .is described <I living 150 million years later than HyracothefjlJm .and Anthitheriur is again misspelt. If you do buy this set. therefore. be vet cautious in the use of the material that accompanies it. .David K. Loydell . . School of Earth,Eovironmental aod Physical Science Univ.ersity of Ports .. mouth BurnabyBuilding Burnaby Road Portsmouth PO I lQl NEW MEMBERS We welcome the following new members to the Association: Mr Martin Allbutt, Church Stretton. Shropshire. MI" Colin Armstrong, Sherburn High School, Leeds. Mr David A. Bishop, Altrincham.<:heshire. Miss ChristineBlake, Hengoed, Mid Glam. Miss JoanneBowen. Winsford. Cheshire. Mr. A. Brown. Haverhilt. Suffolk. Ms Chris .Brown; Broadstone. Dorset. MrsAlysoun Fenn. St Ives. Cambridge. Mr Roger Freeman, Blue Sch:ool~Wells. Somerset. Mr ChrisGlover. Stourbridge. Mr Oarren Harvey. Witham, Essex. Or DavId Harrisofl, Chester. Mrs]. Hayden. Stockport. Cheshire. Mr Graham HoHand, Liverpool. Miss ChantalJohnson. Romiley, Cheshire. Mr John Kar. Grange-over-sands. Lancs. Or Heleri King, University of Southampton. Mr>Petet Mason. Wakefield Grammar School. Mr Andrew Mathieson, Portishead; Bristol. Teaching Earth Sciences: vol. 23, pt. 3 (1998) Mr Andrew Magnay, Hallow. WQrcs. Professor Bm McGuire, University College London. Miss Louise Moir. Skegness Grammar School. MrReay Morrison, Bury, Lancs. MrRuss Needs. Milton Keynes. . Ms Chrissie Nienaber-Roberts,Yancouver. Canada. Mr Graham Oxhotrow, Bishops Stortford, Herts. Or H.M. Pedley. University of Hull. Miss Louise Pownall, Swindon. Wilts. The. President, Geograp,hicatAssociation, Sheffi·eld. Mr Ashley Ross, Westdiff·orHea.Essex. Dr Oavid Spencer. University of Maine, USA Mr N.J. Taylqr.Abergavenny.. Mr Stewart Tayior,Oklbury. West Mld/ands. Dr Johanna Thomas, British Geological Survey,Keyworth Notts. Mrs. Lucy Thomas, Mobi:!erley. Cheshire. Mr Alan Thompson, Beechen Cliff School, Bath. Mrs Margaret Yernon, National Mining Museum. Mr John Whitehead, Cleethorpes. Mr I. Winterford, Arnold School, Blackpool. 154 SHOPFLOOR: Measuring the Earth's circumference with a yardstick (the easy way) Gene G. Byrd In "The Universe in the Classroom" in the March/June 1974 issue of Mercury, O. Richard Norton described a possible modern-day re-enactment of Eratosthenes' measurement of the circumference of the earth. In teaching elementary astronomy laboratory courses in the Universities of Texas and Alabama, I have used a variant of this experiment that overcomes some of the problems of carrying out the measurement. The principle is exactly the. same as in Eratosthenes' measurement except that the star Polaris is used instead of the sun. Polaris is so far away that its light rays are parallel. Since it is the pole star, it stays very nearly at rest as the earth rotates on its axis and revolves about the sun. Thus, any north or south movement of an observer causes the altitude or angle of Polaris above. the northern horizon to change by an amount which is the same fraction of 360" as the distance moved is of the circumference of the carts. For example, if one goes from Austin, Texas to Dallas, Texas (200 miles), Polaris moves about 3° higher in the sky. The relationship: 3°/360 =200 miles/circumference of the earth in miles gives the circumference of the earth. [Metres can be equally used.] Q Of course. to take this measurement, one needs to have an instrument for measuring the altitude of Polaris. For northsouth distances around ISO miles or larger, a simple device using a metre rule. a sheet of polar graph paper, cardboard, drawing pins, tape, thread, and a penny (or a small weight) will be sufficient. The construction ana use uf this device (a crude quadrant) are shown in the illustration (Figure I). correctly. The out-of-town student then goes home and hopes for a clear night. Since Polaris is not exactly at the north celestial pole, the observation should be made at about the same time of night as the previous observation. If the experiment is rained off, the student has at least learned to find Polaris, measured his latitude. and learned about the problem of weather in observational astronomy. Depending oh how large the north-south distance between observing points is, the student can even go home some succeeding weekend to try for a second measurement. Alternatively, two schools sufficiently far apart latitudinally could co-operate in the experiment, though here there would be no chance to check readings between the two. It is better to use the same instrument in exactly the same manner for both measurents. The errors in construction and use tend to cancel out and better accuracy is obtained. A road map or even auto odometer readings can be used to estimate the north-south distance travelled. Values within a few thousand miles of the earth's true circumference can easily be obtained by students travelling 150 to 200 miles north·south. Using Polaris is more convenient than using the sun because Polaris does not require two measurements at apparent noon made Simultaneously (or one day apart). Gene Byrd University of Alabama *, Many students in university classes are from out of the area, and go home over weekends or holidays. In doing the experiment. local students can work as partners with out-of-town students. The altitude of Polaris is preferably measured some weeknight before the student leaves so the partners can check their value with the instructor to see whether the star used is indeed Polaris and whether the instrument is being used Metre Centre Thread Polar Graph Paper Pasted To Label Angles As Shown Tape Drawing Pins Read Altitude Figure ,. A simple instrument for measuring the altitude of Polaris. Teaching Earth Sciences: vol. 23, pt. 3 (/998) 155 Eafrth Science Teachers'Associatio:n , THEMATIC TRAI>LS GEOLOGY AND THE BUILDINGS OF OXFORD Pawl Jenkins A walk: through the city of Oxford is likened to vi~iting an open-air museum. Attention is drawn to the variety of building materials both ancient and modem, used in the fabric, of the city. Discussion of their suitability, durability, susceptibility to. pollution and weathering, maintenanceand periodic replacement is raised. 44 pages. 22 illustrations,lSBN 0948444 09 6 Thematic Trails (1988) £2.40 'Strawberry Water to Marsland Mouth', 'Prawle Peninsula lqndscape Trail' and 'Burrator Dartmoor Landform .Trail' 10 pages, to illustrations Thematic Trails (1993 edition) £2.40 GEOLOGY AT HARTLAND QUAY Ch-:-is Corn(ord & Alan Childs In ashon ellfMoot walk along the beac~ at Hartland Quay, visitors arE! provlt!e~ with a straightforward explanation of the local rocks and their history. Alternative pages provide a deeper commentary on aspects of the geo~ and in particular provides reference notes for examining the variety of structures exhibited in this dramatic location. 40 pages, 47 illustrations, ISBN 094844412. 6 Thematic Trails (1989) £2.40 MALVERN HILLS; a student's guide to the geology of t}le .Malvems. D. W.Bullard (1989) The booklet includes' detailed description of 21 geological sites of interest in the area. '. 73 pages, 31 illustrations, ISBN 086139 548 4 (NCC) £2.25 THE CLIFFS OF HARTLAND QUAY Peter Keene Interpreting the shapes of coastal landfarms is. introduced as a method of understanding something of the environmental history of this dramatic cPasta~ landsCape. A short walk following the coastal path to the south of Hartland Quay puts this strategy into practice. 40 pages, 24 illustrations, ISBN 0948444053 Thematic Trails (1990) £2.40 STRAWBERRY WATER TO MARSLANDMOUTH PeterKeene A short cliff-top walk between the small but spectacular coastal coombes of W~come Mouth and MarslandexpTalns what beaches, streams and valley sides can tell us of the history of this eoastallandscape. 40 pages, 24 illustrations, ISBN 0948444 06 I Thematic Trails (1990) £2.40 VALLEY OF ROC;KS: LYNTON Peter Keene & Brian Pearce The drama of the valley is ~Iored both by offering explanation for the spectacular scenery and by recalling its theatrical setting as seen through tile eyes of those who have vi$ited the valley in the past. 44 pages, 35 illustrations, ISBN 0 948444 25 8 Thematic Trails ( (990) £2.40 THE CLIFFS OF SAUNTON Peter Keene & Chris Cornford In a short cliff-foot walk along the beach at Saunton. visitors are provided with an explanation for the local rocks that make up the cliff and the . shore. Alternative' pages Pl70vide a deeper cQn1mentary on aspects of the gElOIOgy and a chance on the return walk ~'reconstruct the more recent history of this coast by a practical examination of the cliff face. +4 pages. 30 iUustrations. ISBN 0948444 24 X Thematic Trails (May 1993) £2.40 INTERPRETING PLEISTOCENEDEPOSITS Peter Keene A field interpretation guide for beginners.. A fSimpleteaching model using an adapted' graphic log sheet. Of wide general educational application, but designed for use with the fol~wing trails: 'Westward Ho! Coastal landscape Trail', 'valley of Rocks,lynton'; 'The Cliffs of Saunton', MEN DIPS .New Sites for Old; a student's guide to the geology of the east Mendips. This guide gives a detailed deScription of 39 ·sare. accessible sites chosen for their educational potential. 192 pages, 46 illustrations,lSBN 086139 319 8 (Nee (985) £2.50 WENLOCK EDGE;. geology teaching trail M. J. Harley (1988) Six sites suitable for· educationalfteldworkare described and suitable exercises outUned. 22 pages, 15 illustrations. ISBN 086139 403 8 (NeC) £1.50 BURRATOR. DARTMOOR. LANDFORM TRAIL Pe~r Keene& Mike Harley (lg81) An interactive Circular ~ mile walk exploring the evolution 01 tor and valley . scenery on Dartmq.or. 21 pages, 12 Ulustrations, ISBN 086[39 385.6 (NeC) £1.50 THE ICE AGE IN CWMIDWALThe.lce Age inves~Cwm Idwat with a IaOdscape whpse combination 9f ;Iaciological. geqlogicaland: florist/c. elements is unsurpa;Sse<l itrmollntitln .Britain~Cwm Idwat ~re;ldily accessible on good gatbswithln a few minutes walk oft/l&moclemA5 route through Snowdonia. 22 pages, f6 illustrations, ISBN 0 9511175 48 Addison landscape Publications (1988) £3.00 THE ICE AGE IN Y GLYDERAU ANDNANT FFRANCON Ice in ~e:laSt main glaciation in Wales Carved the glacial highway of Nartt ffrancon throUgh the heart of SnQwdon~ so boldly tOel)$Ute its place amongst the best koownnaturallandma;rks In Brititln. ~pnenomena is explained ina way that is attractlveto both specialist mid visitor alike. 30 pages. 20 illustrations, ISBN 0 9511115 1 X . Addison landscape Publications (1988) £3.00 as LONDON. ILLUSTRATED GEOLOGICAL WALKS. BOOK' (TheCit}') Adds to the well-known'evsneraccOunts Qf.thebul~ings Of ~e City of London by oft'ering comment upOn tile roel< types used in familiar City streets. Maps set out the route clearly. No previous knowledge of geology is: assumed. 98 pages, 98photograpns, 14 maps, ISBN () 7073 0350 8 Geologists' Assodatl9n (1984) £4.95 LONDON. ILLUSTRATED GEOLOGICAL WALKS. BOOK 2 (The West End) A wide ran~ of exotic rock types are found In the shop fronts· of Piccadilly. T ottenham 4urt Road and the office blocks of Centrallondon•. Again no previous know(etlge of geolOgy ill aSsumed. 142 pages'I28phQtOs, 16 maps, ISBN.O 7073 04164 GElOlogists' AssoCiation (1985) £4.95 ORDERS TO: Geoff Nicholson. 28 Harthill Ave., Leconfield. Beverley, East Yorkshire HU17 7LN • • Official orders will be invoiced. • Cheques and postal orders should be made payable to ESTA • Key S~age 3 Science of the Earth I 1-14 Units have been devised to introduce Earth Science to pupils at Key Stage J level as part of their National Curriculum studies in Science and Geography. Each Unit occupies about one double period of teaching time and the Units are sold as J-Unit packs. Units that are available now are:i l GW: Groundwork - Introducing Earth Science GW I - Found in the Ground GW2 - Be a Mineral Expert GWJ - Be a Rock Detective Life from the Past - Introducing Fossils LP I - Remains to be seen LP2 - A well-preserved specimen LPJ - A fate worse than death - fossilization! Moulding Earth's Surface - Weathering, Erosion and Transportation ME I - Breaking up rocks ME2 - Rain. rain and rain again MEJ - Landshaping Power from the past: coal (a full colour poster is available with this Unit for a p & P charge of £ 1.1 5 (inc. VAT) please indicate if you do not require this. PP I - Coal swamp PP2 - Layers and seams PP3 - 'Unspoiling' the countryside Hidden changes in the Earth: introduction to metamorphism HC I - Overheated HC2 - Under Pressure HCJ - Under Heat and Pressure Magma - introducing igneous processes M I - Lava in the lab. M2 - Lava landscapes MJ - Crystallising magma Second hand rocks: Introducing sedimentary processes SR I - In the stream SR2 - Blowing hot and cold SRJ - Sediment to rock, rock to sediment Bulk constructional minerals BM I - What is our town made of? BM2 - From source to site BMJ - Dig it - or not? Steps towards the rock face - introducing fieldwork FW I - Thinking it through FW2 - Rocks from the big screen FWJ - Rock trail Earth's surface features ES I - Patterns on the Earth ES2 '- Is the Earth cracking upl ESJ - Earth's moving surface Power source: oil and energy El - Crisis in Kiama - which energy source nowl E2 - Black gold - oil from the depths EJ - Trap - oil and gas caught underground Water overground and underground WG I - Oasis on a desert island-the permeability problem WG2 - Out of sight, out of mindl - waste disposal and ground water pollution WGJ - The dam that failed i l LP: i l ME: i l PP: ilHC: i l M: ilSR: ilBM: i l FW: ilES: ilE: ilWG: ~ SPECIAL REDUCED PRICE ~ £2.00 each (post free) for Key Stage 3 A Teachers' Guide to the 'Science of the Earth' Approach - £ 1.00 Key Stage 4 Science of the Earth Units are designed to introduce Earth sciences to all in the upper secondary school and as such fill a void in present publishing. The Units cover material in Science in the National Curriculum. mainly Attainment Target 3. The following are available only as 5-unit, bound sets. il Unit I: Unit 2: Unit 3: Unit 4: Unit 5: Will my gravestone last? Earthquakes - danger beneath our feet Fluorspar - is it worth mining? Building sedimentary structures - in the lab and millions of years ago Waste - and the hole-in-the-ground problem ilUnit6: Unit 7: Unit 8: Unit 9: Unit 10: Nuclear Waste - The way forward? Neighbourhood stone watch Moving ground Ground water supplies: A modern Jack & JiII story Astrogeology - and the clues on the Moon ilUnit Unit Unit Unit Unit The Water Cycle Which roadstone? The geological time scale Temperatures and pressures in the earth Rock Power! - Geothermal energy resources 11 : 12: 13: 14: 15: il Unit 16: Unit 17: Unit 18: Unit 19: Unit 20" Earth's patchwork crust - an introduction to plate tectonics Cool It!: liqUid magma to solid rock Salts of the Earth The day the Earth erupted - volcanoes 5.0.5. - Save our sites: Earth Science Conservation in Action SPECIAL REDUCED PRICE £5.00 per set (post free) Routeway - solving planning and technical problems of building a major road. A three-unit pack dealing with aspects of planning and engineering geology and associated environmental problems. Science and Geography courses at Key Stage 4. Also applicable to problem-solving modules in 'A' level or GNVQ Science or Geology courses. Price: £4.95 SoE I: Changes to the atmosphere SoE2: Geological Changes Earth's Structure and Plate Tectonics SoE3: Geological Changes Rock Formation and Deformation Investigating the Sdence of the Earth. Practical and investigative activities for Key Stage 4 and beyond. Price £2.95(Per Unit) Please note - to claim ESTA member prices on the above items, you must enclose a copy of this advertisement or an ESTA order form, or simply mention your ESTA membership. ORDERS TO: Geo Supplies Ltd., 16 Station Road, Chapeltown, Sheffield S35 2XH. Tel: (0114) 245 5746 • Official orders will be invoiced .• Cheques and postal orders should be made payable to Geo Supplies Ltd. GRAIN SIZE SCALE I...Iri1ated cards specially printed for ESTA (6x 9 an credit card size). They show grains from coarse sand down to silt. lOp each lOp each for 20 to 99 copies 100 copies or more £ 15 1000 copies £ I00 FILM STRIPS en--..,....,... unmounted scrips) I. IlETAMOIIPHIC ROCKS bp Con GIIIen 24 ....... 1howInc IMCImOI'phIc .......... rocks and photomIcroaraph oI ....ncwphic rocks and ........ £4.50 per unmounted suip 2. GEOLOGY FROM SPACE (PLATE TECTONICS) 12 ...... 0I ...... 11n1py from NASA and USGS ~ Ispects of .... tIICtIOnIcs • vt.w.cI from space. The noc. that ICiCIOII'IpIIIY die IIrIp .... wrItmn by Sc.¥e FIIaon and Include ••1CIaIIIId IIcacdIes of ......... which .... copyll&ht .... for class .... 0.50 per unmounted POSTCARDS I. THE FLOOR OF THE OCEANS (14 x tan) mln.........sIon 01 wd 1nIp. 2Sp IICh, 10 or more lOpeKh. 2. BUILDING STONES A . . 0116 pOICaI ds depIctIrrc ~ or OI"IIIIIIIIICII_ to be found In IDWnI and cIdIs chr'ou&hout ... CIOUiIII'y. AI ...... 1-------------------.. .; 1--------------------..... IIrIp. BOOKLETS Br WORKSHEETS I. SAFETY IN EARTH SdENCE FIELDWORK GuIdIIne noc. on tIeIdwortt J.denhIp. RecommencIadons of die ESTA FWcIwark Commiaee, £1.00. 2. LETS LOOK AT CHINA CLAY, pubIshed by MIMCU. ....... oIll1lornlldol .. could be used from PrImary to A-Ie¥eI. The pack CIOIIIIIa 0142 worbI..a, a pupil resource book and a teacher's pIde. . . . . . . to 0.00. . 3. LETS LOOK AT SAND, published by MIMCU. Ai.- ",~ CGUId be used from primaty to A Ie¥eII A CCIIIIf*Iian to"', IDGIt at China Clay-. k consIsa of 65 worbI..a, a pupa resource book and a teacher's aulde. RecIucecI to ... S. .. 7. 0.00. . HOW THE EARTH WORKS: Eanh Science at the National CurrIculum KS3. DesIped to help the busy scIMce teacher, wIch no . . . . ecperdM. cWIvw ... Eanh Science compoI_1t of the National CurrIculum. £10.50. EXPLOIUNG EAIlTH SCIENCE: Eanh Science ActIvItIes for Key I 11 2 (Nonhancs). Price £15.00. :y SPACE: Eanh's place In die universe. CampI_henslYe help for K., Sea&- I 11 2 (NonhInts). PrIce £ 18.00. PLANET EARTH: Usbome Science and Exper:m.a.. A practical InIroducdon to Earth Science and PhysIcal Geocnphy sugesdn& many aaMdII and praIects. PrIce: £4.50. s..- ROCK, MINERAL Br FOSSIL KITS I. ESTA MINERAL SAMPLES Boud . . 01 ten mInW'aIs ~tIte, ~ plena, pyrite. mica, InII""'o calcite. halite, quartZ & feldspar), plus . . nail. copper cOin. senile .... dropper boaer & onaanIfIer. EssentIal for use wIch acdvIdIs In PEST 9· MINERALS (copy 1nducIed). Suitable for KS2/KS3. £15.00 2. DIVEIISITY OF UFE • FOSSIL REPLICAS SET Boud faaII ....... selected to IIIuscrate the ~ 01. _ poIoaIcaI doni (dinosaur tooth, triIobIc., ammonite, shark tooth, IcIhJoIaur tooth, tsh. -1IO'd*I, coral, repdIe foocprInt. .... fern. . . IIy 11 shrimp). Produc:ecI by GEOU (Open UniversIty Dept 01 Earth Sciences) 11 Includes cIetaIIecI noc. and a copy 01 PEST I • FOSSILS. SubbII for KSlIKS3IKS4. £ 16.00 3. ESTA ROCK KITS • ask for details size. £3.50. MAPS AND W ALLCHARTS I. GEOLOGICAL STIlUCTUU OF GREAT IIIUt pubIIIhed bp .... ca.Io&IaI SocIetJ of"-'The dart consIsa oIa" colour tIICtDIIIc: .............. ... ~ ... and twwIty .... block .............. ... ...... scructww 0I1p8C111c ....... ($ID ........ I . x rT an). a..st".,.,." dIM 2. GEOTHERMAL MAP OF THE UNITED KINGDOM pull ....... bp IIGS ~ far UnIt IS· R«i 10wer ThIs coloured ct.n consIsa of (scale 1:I.5OO.CIOO) ~ ... pocheIlnaI JIC*IIdII 01 ... UK . . . wIdI •• IOGdoI. dIIa Mw ... IIIIjor .... and praIects. sa. approx. 80 x 80 an. a..., U" ,.. ,.,." ..., 3. THE FLOOIl OF THE OCEAN ............ bp ....... TIwp ~ far UnIt 16· EId's".,.... QUIt - , . . . . . . , , ,.,.. UnIt · EDrda's 5pecIaIy ImporIIMI by ESTA from ... USA. PrInt8d on .......... ..,.., a..,.rb 1IIIp . . . . . . . ....., . . . . . 01 ... oc.Iloor In.,aphlc . . . . " ..... , . . , . . , . . . ... LE PUYS YOI CANOES (MNEItGNE) PublIshed by'" Fnnch ...... 01 GeoJocy and ............ AIMrJnI VoICInoes RIpInII PIrtc. ~ far ". ,.. ,.,.."..,..". A foIdecI poIoaIcaIlIIIp 01 ... ,.... at I: 25.000 scale coIaurUy ........... volcanic ..... £9.00. An ~'1'" 0116 posuards his be.! cut Into 4-M sa.cI ..... for ............ . £5.00. s.t of...,. MIll ....... S. THE GEOLOGICAL COLUMN' PublIshed by ~ .......... ThIs sbc peneI colour ..... cowrs plant and ..... MaIudon, .... tectonic prcCII• •• oropnIc actMty and peIIeocIIl.... (1IIIInIy wIdI . . . .a to ........) . well. ~ ... cIuradon 01 ... periods. s.-.ch rwwIsId edIdon 1992· £1.20. 6. GELOGICAL MAP OF THE WOIILD PublIshed by OUIESSO wIIh help from ESTA. ~ oc.Iic crust coIoIr coded by ... b.udIuI! 100an x ISO an. Price a.oo. 7. WILLIAM SMITH MAP of IllS PubIshed by the LiYerpooI GeoJo&icaI Sociely from chIir ....... sheea.. A colour 6IcsIn6 01 dIk fInt poIoaIcaIlIIIp 01 &W-L 11 SOUIhem ScodInd reduced to a ............ (100 x 7Oan). AcIdIdonaI noIIeS 1CiCIOII'IpIIIY. 0.00 per rolled...,. -race,....".. "J." "'1" w'"