Independent Geologist`s Report on the Mineral Assets of Polymetals

Transcription

Polymetals Mining Limited
Independent Geologist's Report on the Mineral Assets
of Polymetals Mining Limited
J_1180_G
Principal Author:
Paul Blackney BSc Hons, MAusIMM, MAIG
Principal Reviewer:
Ian Glacken FAusIMM (CP), CEng
March 2011
Independent Geologist's Report on the Mineral Assets of Polymetals
Mining Limited
Perth Office
Level 4, 50 Colin Street
West Perth WA 6005
PO Box 1646
West Perth WA 6872
Australia
Doc Ref:
110317_J1180_Optiro_IGR_Polymetals_FINAL.docx
Tel:
Fax:
Print Date:
Number of copies: 2
Optiro Pty Limited
ABN: 63 131 922 739
www.optiro.com
Optiro: 1
Polymetals Mining Limited: 1
Principal Author:
Paul Blackney BSc Hons,
MAusIMM, MAIG
+61 8 9215 0000
+61 8 9215 0011
Signature:
Date:
17 March 2011
Contributors:
Ian Glacken FAusIMM (CP), CEng. Dr Katrin Kärner MAusIMM
Principal Reviewer:
Ian Glacken FAusIMM (CP), CEng
Signature:
Date:
17 March 2011
Important Information:
This Report is provided in accordance with the proposal by Optiro Pty Ltd (“Optiro”) to Polymetals Mining Limited and the
terms of Optiro’s Consulting Services Agreement (“the Agreement”). Optiro has consented to the use and publication of
this Report by Polymetals Mining Limited for the purposes set out in Optiro’s proposal and in accordance with the
Agreement. Polymetals Mining Limited may reproduce copies of this entire Report only for those purposes but may not
and must not allow any other person to publish, copy or reproduce this Report in whole or in part without Optiro’s prior
written consent.
Unless Optiro has provided its written consent to the publication of this Report by Polymetals Mining Limited for the
purposes of a transaction, disclosure document or a product disclosure statement issued by Polymetals Mining Limited
pursuant to the Corporations Act, then Optiro accepts no responsibility to any other person for the whole or any part of
this Report and accepts no liability for any damage, however caused, arising out of the reliance on or use of this Report by
any person other than Polymetals Mining Limited. While Optiro has used its reasonable endeavours to verify the
accuracy and completeness of information provided to it by Polymetals Mining Limited and on which it has relied in
compiling the Report, it cannot provide any warranty as to the accuracy or completeness of such information to any
person.
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TABLE OF CONTENTS
1.
EXECUTIVE SUMMARY ................................................................................ 1
1.1.
1.2.
1.2.1.
1.2.2.
1.2.3.
1.3.
1.3.1.
1.3.2.
1.3.3.
PURPOSE...............................................................................................................................1
SUMMARY OF ASSETS ...........................................................................................................1
CANBELEGO ................................................................................................................................ 2
DREW HILL .................................................................................................................................. 3
BOORARA ................................................................................................................................... 4
POLYMETALS’ STRATEGY AND PROPOSED WORK PROGRAMME ..........................................5
CANBELEGO ................................................................................................................................ 5
DREW HILL .................................................................................................................................. 5
BOORARA ................................................................................................................................... 6
2.
INTRODUCTION .......................................................................................... 7
2.1.
2.2.
2.3.
2.4.
2.5.
2.6.
2.7.
TERMS OF REFERENCE...........................................................................................................7
PURPOSE...............................................................................................................................7
MINERAL ASSETS ..................................................................................................................7
LEGAL TENURE ......................................................................................................................8
PRINCIPAL SOURCES OF INFORMATION ................................................................................8
QUALIFICATIONS AND EXPERIENCE.......................................................................................9
INDEPENDENCE .....................................................................................................................9
3.
CANBELEGO.............................................................................................. 10
3.1.
3.2.
3.2.1.
3.2.2.
3.3.
3.4.
3.4.1.
3.4.2.
3.5.
3.6.
3.7.
LOCATION, TENURE AND PHYSIOGRAPHY ........................................................................... 10
GEOLOGICAL FRAMEWORK ................................................................................................. 14
REGIONAL GEOLOGY ................................................................................................................ 14
LOCAL GEOLOGY ....................................................................................................................... 14
MINERALISATION ................................................................................................................ 19
EXPLORATION AND MINING HISTORY ................................................................................. 20
MOUNT BOPPY ......................................................................................................................... 20
EXPLORATION LEASE EL5842 .................................................................................................... 22
MINERAL RESOURCES ......................................................................................................... 24
MINING AND PROCESSING CONSIDERATIONS..................................................................... 26
EXPLORATION POTENTIAL .................................................................................................. 27
4.
DREW HILL................................................................................................ 28
4.1.
4.2.
4.2.1.
4.2.2.
4.3.
4.3.1.
4.3.2.
4.3.3.
4.3.4.
LOCAL GEOLOGY ....................................................................................................................... 32
MINERALISATION ................................................................................................................ 33
WHITE DAM .............................................................................................................................. 33
WHITE DAM NORTH ................................................................................................................. 35
WHITE DAM SOUTH .................................................................................................................. 36
VERTIGO ................................................................................................................................... 36
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4.3.5.
4.4.
4.5.
4.5.1.
4.5.2.
4.5.3.
4.6.
4.6.1.
4.6.2.
4.6.3.
AMBUSH ................................................................................................................................... 36
MINERAL RESOURCES AND ORE RESERVES ......................................................................... 38
WHITE DAM .............................................................................................................................. 38
VERTIGO ................................................................................................................................... 39
WHITE DAM ORE RESERVE ....................................................................................................... 39
MINING, METALLURGICAL AND PROCESSING CONSIDERATIONS ........................................ 40
MINING ..................................................................................................................................... 40
METALLURGY ............................................................................................................................ 40
PROCESSING ............................................................................................................................. 41
5.
BOORARA ................................................................................................. 42
5.1.
5.2.
5.2.1.
5.2.2.
5.3.
5.4.
5.4.1.
5.4.2.
5.5.
5.6.
LOCAL GEOLOGY ....................................................................................................................... 47
MINERALISATION ................................................................................................................ 47
EXPLORATION ........................................................................................................................... 49
PRODUCTION ............................................................................................................................ 50
MINERAL RESOURCES ......................................................................................................... 51
EXPLORATION POTENTIAL .................................................................................................. 52
6.
EXPLORATION STRATEGY AND BUDGET .................................................... 53
6.1.
6.1.1.
6.1.2.
6.2.
6.3.
CANBELEGO ........................................................................................................................ 54
MT BOPPY EXTENSION PROGRAMME ...................................................................................... 54
CANBELEGO EXPLORATION PROGRAMME ............................................................................... 54
DREW HILL .......................................................................................................................... 55
BOORARA ........................................................................................................................... 55
7.
REFERENCES ............................................................................................. 56
8.
GLOSSARY OF TECHNICAL TERMS .............................................................. 58
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TABLES
Table 1.1
Table 1.2
Table 3.1
Table 3.2
Table 3.3
Table 4.1
Table 4.2
Table 4.3
Table 4.4
Table 5.1
Table 5.2
Table 5.3
Table 6.1
Project summary ........................................................................................................................ 2
Polymetals’ proposed two year exploration and development budget ..................................... 5
Canbelego tenements .............................................................................................................. 10
Mount Boppy Mineral Resource estimate, 2008 ..................................................................... 25
Summary of the plant performance at Mount Boppy, from Lawry (2010) .............................. 27
Drew Hill tenements ................................................................................................................. 28
Significant gold intercepts from the 1998 and 2010 drilling programmes at White
Dam North ................................................................................................................................ 35
Significant gold intercepts of the 2010 drilling programme at Vertigo .................................... 36
Combined White Dam and Vertigo ordinary kriging (OK) mineral resource estimate
using a cut-off grade of 0.3 g/t gold for White Dam and 0.4 g/t gold for Vertigo,
from Exco (2011a and 2011b) .................................................................................................. 39
Boorara tenements................................................................................................................... 42
Polymetals' exploration activities, from Kelty (2005) and Bolger (2006, 2007b, 2008,
2009 & 2010) ............................................................................................................................ 50
Polymetals 2006 resource categories for the Northern Stockwork Zone (NSW),
Cataract (CAT), Crown Jewel (CRJ) and the Southern Stockwork Zone (SSW) using a
cut-off grade of 0.5 g/t gold, from Bolger (2007a) ................................................................... 52
Polymetals proposed exploration and development budget for its key assets in
Australia.................................................................................................................................... 53
FIGURES
Figure 2.1
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 3.10
Figure 3.11
Figure 3.12
Figure 4.1
Figure 4.2
Figure 4.3
Project locations ......................................................................................................................... 8
Location of Polymetals' Canbelego mineral leases, gold leases and mining lease
application ................................................................................................................................ 11
EL5482 located around the Canbelego mining tenements ...................................................... 12
View from top of Mount Boppy looking southeast towards mine site .................................... 13
View north-west from mine site with pit west wall ramp in foreground and Mount
Boppy in background ................................................................................................................ 13
Tectono-stratigraphic units of the Cobar Basin, with the Canbelego Project being
located in the northern extremity of the Canbelego-Mineral Hill Rift Zone ............................ 15
Exploration prospects on exploration licence EL5842 .............................................................. 16
Regional mine and resource overview in the Cobar region of NSW ........................................ 17
Mount Boppy local geology and drill hole locations ................................................................ 18
Brecciated ore at Mount Boppy, drill hole PMS123 at 109.4 m ............................................... 20
Gold production from the Mount Boppy mine and timing of some events affecting
production rates, from McQueen (2005) ................................................................................. 21
Pipeline Ridge cross section showing drill hole intercepts and interpreted geology ............... 23
Mount Boppy Mineral Resource relative to existing pit limit (long axis of pit at rim is
400 m)....................................................................................................................................... 26
Location of the Drew Hill tenements ........................................................................................ 29
Drilling and vegetation at Drew Hill ......................................................................................... 30
Geological domains of the Curnamona Province ..................................................................... 31
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Figure 4.4
Figure 4.5
Figure 4.6
Figure 4.7
Figure 4.8
Figure 4.9
Figure 5.1
Figure 5.2
Figure 5.3
Figure 5.4
Geological framework showing the regional redox boundaries in the southern
Curnamona Province, modified after Leyh and Conor (2000) .................................................. 32
Interpreted geology at White Dam over aeromagnetic image, after Bargmann
(1999) ....................................................................................................................................... 33
Banded biotite-altered gneiss from the White Dam orebody .................................................. 34
Long section of the White Dam deposit at line 6,449,000 mN................................................. 35
Historical and recent drilling work at prospects in the Drew Hill area ..................................... 37
White Dam open pit, May 2010, viewed from north to south at west end of pit .................... 40
Boorara Project - prospect locations and geology ................................................................... 44
Rehabilitated drill site at Boorara............................................................................................. 45
Regional Geology ...................................................................................................................... 46
Prospect localities in the Boorara Mining Centre (north is to the top of the page) ................. 48
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1. EXECUTIVE SUMMARY
1.1.
PURPOSE
Optiro Pty Ltd (Optiro) has prepared an Independent Geologist’s Report (IGR) on the exploration and
mineral resources of Polymetals Mining Limited. This report represents a Competent Person’s
review and independent assessment of the geology, exploration data, Mineral Resources and
exploration potential of Polymetals Mining Limited’s mineral assets in Australia. It is our
understanding that this report will be included in a Prospectus to be lodged with the Australian
Securities and Investment Commission (ASIC) for a proposed listing on the Australian Securities
Exchange (ASX). The purpose of the admission document is to offer for subscription a maximum of 7
million ordinary shares at an issue price of A$1.00 to raise up to A$7,000,000.
1.2.
SUMMARY OF ASSETS
Polymetals Group Pty Ltd is a privately owned Australian producer of base and precious metals with
operations in South Australia and exploration/development projects in New South Wales and
Western Australia. Polymetals Group Pty Ltd is becoming a public company limited by shares and
renaming to Polymetals Mining Limited.
The term 'Polymetals' in this report refers to the various entities of the Polymetals group of
companies, including Polymetals Mining Limited, Polymetals Operations Pty Ltd, Polymetals (White
Dam) Pty Ltd, Polymetals (WA) Pty Ltd and Polymetals (Mt Boppy) Pty Ltd.
Polymetals’ mineral assets comprise three projects in Australia:
Canbelego Project (includes the Mount Boppy Gold Mine), New South Wales
Drew Hill Project (includes the White Dam Mine), South Australia
A joint venture with Exco Operation (SA) Ltd (Exco) with Polymetals holding a 25% interest
Boorara Project, Western Australia.
Summaries of Polymetals' projects are presented in Table 1.1.
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Table 1.1
Project summary
Canbelego
Ownership
100%
46 km east of Cobar, New
South Wales
2
204 km
Palaeozoic epithermal gold,
Cobar-style gold mineralisation;
prospective for gold and base
metals
Location
Area
Exploration
Mineral Resource
Cut-off grade
Measured
2.5 g/t gold
30,000 t
5.0 g/t gold
45,000 t
4.5 g/t gold
Indicated
195,000 t
(stope fill)
3.6 g/t gold
Inferred
365,000 t
4.6 g/t gold
Production
Total gold metal
#
Drew Hill
Boorara
25% Gold Production JV;
25% Exploration JV
85 km west of Broken Hill,
South Australia
2
728 km
17 km east of Kalgoorlie,
Western Australia
2
33 km
Proterozoic IOCG deposit;
prospective for gold and
copper metals
Archaean shear-hosted gold;
prospective for gold and
base metals
0.3 g/t gold for White Dam
0.4 g/t gold for Vertigo
0.5 g/t gold
-
100%
-
300,000 t
1.2 g/t gold
5,164,000 t
#
1.1 g/t gold
990,000 t
1.3 g/t gold
3,283,000 t
0.9 g/t gold
611,000 t
1.5 g/t gold
87,900 oz
275,000 oz
84,600 oz
Historical
~425,000 oz Mount Boppy
Mine 1901 to 1976
or 493 koz to 2005
-
~31,500 oz
Present
-
49,600 oz White Dam Mine
to December 2010
-
White Dam Mineral Resource depleted by mining to end of September 2010
1.2.1.
CANBELEGO
Polymetals holds six mining tenements and one exploration licence adjacent to the settlement of
Canbelego approximately 46 km east of the regional centre of Cobar in New South Wales. The
Mount Boppy Gold Mine is located on one of these mining tenements.
At Mount Boppy gold production from an underground mining operation commenced in 1901 and
continued to 1923. In its day the mine was one of the largest gold producers in Australia. The
orebody delivered some 417,000 ounces of gold from ore with a notional grade of 15 g/t gold
(12.2 g/t gold recovered). Sporadic operation up to 2002 added a further 7,000 ounces of gold
production. This included gold recovered from the first Carbon-In-Pulp (CIP) plant built in Australia
in 1975 at Mount Boppy to re-treat the historic tailings.
Polymetals re-opened the Mount Boppy Mine in 2002, establishing open cut operations over the
historic underground mine. Between 2002 and the mine closure in 2005, the operations produced
approximately 67,000 ounces of gold from 500,000 t of ore with an average grade of 5.29 g/t gold
(4.2 g/t gold recovered). The site and infrastructure including a 150,000tpa plant is currently under
care and maintenance. Polymetals plans to add to the mining inventory of 560,000 t at 5.14 g/t gold
by delineating additional high-grade ore sources prior to re-commencing mining.
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The current Mineral Resource estimate for the Mount Boppy Mine was completed in late 2008
based on the data available in 2006. Optiro has reviewed the Mineral Resource estimate and
considers it to have been compiled and reported in accordance with the JORC Code (2004). Evidence
from historical mining and past drilling suggests that the mineralised structure, previously mined in
the Mount Boppy pit, continues to the south. In Optiro’s opinion there is potential for extensions to
the mineralisation within this area.
Potential exploration targets surrounding the Mount Boppy mining leases have been identified at
Hardwick’s, Boppy South, Birthday and Reid Rankin’s. Drilling at the Pipeline Ridge prospect within
the exploration licence in the 1990s intersected multiple auriferous zones of two to ten metres
width over a strike length of approximately 500 m.
1.2.2.
DREW HILL
There are five main gold prospects on the Drew Hill tenements that have been the focus of
exploration in recent years. From north to south these are: White Dam North, White Dam (including
the White Dam Mine), White Dam South, Vertigo and Ambush.
Open cut mining, ore extraction and stacking commenced at the White Dam Mine in January 2010
which was officially opened in June 2010. Cyanide dump leaching of ore commenced in March 2010,
with the first gold production achieved in April 2010. The mine is expected to yield approximately
5.1 Mt of ore at a grade of 1.0 g/t gold. At the current mining rate, mining is forecast for completion
in August 2011. Forecast completion of ore processing is within 12 months of completion of mining.
Gold recovered by dump leaching amounts to 49,400 ounces to December 2010 and gold recovery is
reported to be better than predicted.
The Vertigo prospect is located approximately 1 km south-west of the White Dam Mine. This
prospect has been drill tested over several years, with the most recent infill drilling programme
completed in September 2010. A diamond drilling programme was completed in November 2010 to
collect samples for metallurgical, geotechnical and density test work. These data have been used to
update the Mineral Resource estimate for the deposit to an Indicated and Inferred status in January
2011. The Mineral Resource estimates a total of 2.4 Mt at 1.04 g/t gold (82,100 ounces) above a cutoff of 0.4 g/t gold, of which 1.2 Mt at 1.18 g/t gold (46,200 ounces) is assigned to an Indicated
Mineral Resource category.
The White Dam North prospect is located immediately to the north of the White Dam Mine. White
Dam North is a large soil geochemical anomaly, which has been successfully drill-tested during
several exploration campaigns in recent years and will undergo more drill testing in the future.
Recent exploration drilling results at Ambush and White Dam North have been encouraging and
further exploration drilling is planned. Recent drilling results from White Dam South have been
disappointing and no further work is planned on this target in the near future.
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1.2.3.
BOORARA
Polymetals' gold prospects at Boorara are hosted by the Menzies Boorara Shear Zone in the Eastern
Goldfields Province of the Archaean Yilgarn Craton of Western Australia. The Archaean Yilgarn
Craton is one of the largest gold provinces worldwide, with the Golden Mile and Mount Charlotte
gold deposits at Kalgoorlie having produced 1% of the world's total gold production.
Polymetals holds several mining and exploration tenements including the 'Boorara Mining Centre',
which had considerable historical mining in the early 20th century. The historical workings have
produced an estimated 31,400 ounces gold, the majority of this prior to 1916.
Four main areas at the Boorara Mining Centre contain significant gold mineralisation; namely the
Southern and Northern Stockwork zones, Crown Jewel and Cataract-Digger Dam, and all have been
drill-tested by Polymetals in the past years.
A Mineral Resource was estimated in 2006 with a total of 1.3 Mt at an average grade of 1.3 g/t gold
for 54,000 ounces in an Indicated Resource categories and 0.6 Mt at an average grade of 1.5 g/t gold
for 30,000 ounces in the Inferred Resource category.
Marginal extensions to the mineralisation at the Southern Stockwork Zone were drill-defined by
Polymetals in 2009. Infill drilling was also completed at Cataract and at the Northern and Southern
Stockwork zones in order to increase the estimation confidence. Additionally, untested targets have
been drilled between the Southern Stockwork Zone and Crown Jewel. Significant gold mineralisation
was intercepted at all deposits, with some gold interceptions located beyond the 2006 resource
model. In Optiro's opinion Polymetals' 2009 drilling has good potential to expand the current
Mineral Resource estimate. There is also some potential for depth extensions to the known deposits
as much of the current drilling is relatively shallow.
Moreover, there may be potential to increase the estimated resource grade. Historical data show
that there is a potential grade upside of 10% to 15% due to the presence of coarse free gold that has
not been recognised by standard fire analysis. This has been confirmed by results from screen fire
analysis carried out as part of Polymetals' 2009 drilling programme.
Other gold anomalies include Chapple and Golden Ridge North, which are located to the south of the
Southern Stockwork Zone. These two prospects are at an early stage of exploration and require
further work. Limited drilling is planned at Boorara by Polymetals in 2011.
The Boorara area is not only prospective for gold, but also for base metals and silver mineralisation.
The closed Nimbus Silver Mine is located outside Polymetals’ tenements and immediately east of the
Boorara Mining Centre. In 2004, Polymetals produced silver from two open cut mines at Nimbus,
now owned by the Kalgoorlie Ore Treatment Company.
There are numerous other base metal and silver prospects in the Boorara Project area; namely
Gretel, Condor, Brindabella, Tramways, Shamrock and Sovereign. Previous drill-testing, particularly
at Shamrock and Sovereign, resulted in a number of low-grade base metal and gold intersections.
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1.3.
POLYMETALS’ STRATEGY AND PROPOSED WORK
PROGRAMME
Polymetals has proposed a budget which will fund the work required for exploration and resource
development over a two year period for its three project areas in New South Wales, South Australia
and Western Australia (Table 1.2). The majority of the work is focused on the Canbelego Project
which Optiro considers to be reasonable after consideration of the potential for exploration success
provided by each project area.
Table 1.2
1.3.1.
Polymetals’ proposed two year exploration and development budget
Project
Cost [A$M]
Canbelego
5.883
Drew Hill
0.466
Boorara
0.371
Total
6.720
CANBELEGO
Polymetals' exploration strategy comprises two work programmes; near mine and regional
exploration. This work is planned to advance the Canbelego Project towards recommencing gold
production at Mount Boppy. The budget of A$5.883 M fully funds the exploration planned over the
next two years at Canbelego.
The first stage of the near mine exploration will focus on identifying extensions to the Mount Boppy
orebody, with a particular focus on the southern end of the pit where mining and previous drilling
suggest the presence of mineralisation along strike and down dip. If this exploration is successful, a
second stage of drilling would be completed to support a Mineral Resource estimate suitable for
feasibility studies.
Exploration, using both drilling and geophysical surveys, is planned for a number of prospects to test
for Cobar-style precious metal mineralisation within the EL 5842 exploration lease. This work will be
targeted at establishing the existence of mineralisation and any depth extensions suggested by the
Cobar-style mineralisation model.
Other gold and base metal prospects will be explored using a combination of shallow drilling and
ground magnetic surveys.
1.3.2.
DREW HILL
The strategy at Drew Hill is to continue to define Mineral Resources and Ore Reserves to maximise
the operating life of the White Dam Mine. The strategy involves developing near mine targets and
possible extensions to these. Total planned expenditure in the 2011 calendar year is A$2 M of which
Polymetals will contribute A$0.5 M under the joint venture agreement with Exco.
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The most mature target is the Vertigo deposit which is located some 2km to the south of the White
Dam pit. The latest drilling campaign was completed at Vertigo in the latter half of 2010 and a
Mineral Resource was completed in January 2011. Metallurgical test work is ongoing. The Mineral
Resource estimate will be used as the basis of a feasibility study.
Other recent drilling programmes resulted in some success at the nearby White Dam North and
Ambush prospects. The planned drilling budget will continue the exploration of these prospects and
other drilling programmes will test extensions to the White Dam and Vertigo deposits.
Polymetals plans to fund the following year’s exploration expenditure from cash flow from the
White Dam operation.
1.3.3.
BOORARA
Polymetals’ strategy is to expand existing Mineral Resources at Boorara. The exploration effort at
Boorara is ranked lower than that planned for Canbelego and Drew Hill which has led to a modest
planned expenditure level of A$0.4 M over the next year.
This budget will be used to further test depth extensions of known mineralisation and to infill
defined mineralised structures.
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2. INTRODUCTION
2.1.
TERMS OF REFERENCE
At the request of Polymetals, Optiro has prepared an Independent Geologist’s Report (IGR)
describing Polymetals’ key gold and base metal assets in Australia. These assets comprise the
development project Canbelego in New South Wales (including the Mount Boppy Mine under care
and maintenance), the Drew Hill joint venture in South Australia (including the recently opened
White Dam Mine) and the exploration project Boorara in Western Australia.
2.2.
PURPOSE
This report represents a Competent Person’s review and independent assessment of the geology,
exploration data, Mineral Resources and exploration potential of Polymetals mineral assets in
Australia. It is our understanding that this report will be included in a Prospectus to be lodged with
the Australian Securities and Investment Commission (ASIC) for a proposed listing on the Australian
Securities Exchange (ASX).
The objectives of this report are to:
provide an overview of the regional and local geology of Polymetals’ mineral assets in
Australia
describe the geology and potential of the project areas with defined Mineral Resources
highlight other advanced prospects and areas of exploration potential
provide a summary of past and current gold mining activities on and around Polymetals’
properties
describe metallurgical test work and processing
give an opinion on Polymetals' exploration and development strategy and proposed
programmes.
2.3.
MINERAL ASSETS
Polymetals Group Pty Ltd is a privately owned Australian producer of base and precious metals with
operations in South Australia and exploration/development projects in New South Wales and
Western Australia. Polymetals Group Pty Ltd is becoming a public company and renaming to
Polymetals Mining Limited.
Polymetals’ mineral assets comprise three projects in Australia (Figure 2.1):
Canbelego Project, New South Wales (includes Mount Boppy Gold Mine)
Drew Hill Project (includes the White Dam Mine), South Australia. Joint venture with Exco
Operation (SA) Ltd (Exco) with Polymetals holding 25%.
Boorara Project, Western Australia.
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Figure 2.1
Project locations
2.4.
LEGAL TENURE
Optiro has prepared this report upon the understanding that all of Polymetals' wholly owned or
controlled tenements and tenement applications are currently in good standing and has not
independently verified Polymetals' legal tenure over its tenements. Optiro is not qualified to make
statements in this regard and has relied upon information provided by Polymetals.
2.5.
PRINCIPAL SOURCES OF INFORMATION
This IGR is based on technical data provided to Optiro by Polymetals, as well as discussions with
other experts on site during a field inspection of the properties by Mr Ian Glacken (Boorara) and
Mr Paul Blackney (Canbelego and Drew Hill) in May 2010.
Additional relevant material was acquired independently by Optiro from a variety of sources. The
list of references at the end of this report sets out the sources consulted. This material was used to
expand on the information provided by Polymetals and, where appropriate, confirm or provide
alternative assumptions to those made by Polymetals.
The authors have made all reasonable enquiries to establish the completeness and authenticity of
the information provided and identified, and a final draft of this report was provided to Polymetals,
along with a written request to identify any material errors or omissions.
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2.6.
QUALIFICATIONS AND EXPERIENCE
The principal authors of this report are Mr Paul Blackney, Mr Ian Glacken and Dr Katrin Kärner.
Mr Blackney is a Principal of Optiro and a geologist who has over 27 years worldwide experience in
the mining industry. He is a Member of the Australasian Institute of Mining and Metallurgy
(MAusIMM) as well as a Member of the Australian Institute of Geoscientists (MAIG). Mr Blackney
visited the Drew Hill and the Canbelego Projects in May 2010.
Mr Glacken is a Director of Optiro and a geologist with postgraduate qualifications in geostatistics,
mining geology and computing who has over 28 years worldwide experience in the mining industry.
He is a Fellow of the Australasian Institute of Mining and Metallurgy (FAusIMM), a Chartered
Professional Geologist and a Chartered Engineer under the Institution of Materials, Mining and
Metallurgy (IMMM, UK). Mr Glacken visited the Boorara Project in May 2010.
Dr Kärner is a Consultant of Optiro and a geologist who has seven years worldwide experience in the
mining industry. She is a Member of the Australasian Institute of Mining and Metallurgy
(MAusIMM).
This report has been prepared according to the Code for the Technical Assessment and Valuation of
Mineral and Petroleum Assets and Securities for Independent Expert Reports (the VALMIN Code,
2005). The tabulation and classification of Mineral Resources herein and the reporting of
Exploration Results has been carried out according to the Australasian Code for the Reporting of
Exploration Results, Mineral Resources and Ore Reserves (the JORC Code, 2004). Mr Ian Glacken
(MSc, FAusIMM (CP), CEng) and Mr Paul Blackney (BSc Hons, MAusIMM) assume responsibility for
the Mineral Resource statements. Mr Glacken and Mr Blackney are full-time employees of Optiro
and have sufficient experience which is relevant to the styles and types of mineralisation described
and to the activities which they are undertaking to qualify as Competent Persons as defined in the
JORC Code.
2.7.
INDEPENDENCE
Optiro is an independent consulting organisation which provides a range of services related to the
mineral industry including, in this case, independent geological services, but also resource
evaluation, corporate advisory, mining engineering, mine design, scheduling, audit, due diligence
and risk assessment. The principal office of Optiro is at 50 Colin Street, West Perth, Australia, but
Optiro's staff work on a variety of projects in a range of commodities worldwide.
The authors do not hold any interest in Polymetals Mining Limited, its associated parties, or in any of
the mineral properties which are subject of this report. Fees for the preparation of this report are
being charged at Optiro's standard schedule of rates, whilst expenses are reimbursed at cost.
Payment of fees and expenses is in no way contingent upon the conclusions drawn in this report.
Page |9
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3. CANBELEGO
3.1.
LOCATION, TENURE AND PHYSIOGRAPHY
Polymetals holds six mining tenements of about 58 ha (Table 3.1) adjacent to the township of
Canbelego approximately 46 km east of Cobar, New South Wales (Figure 3.1). The Mount Boppy
Gold Mine, which is currently under care and maintenance, is located within one of these mining
tenements (GL 3255). An exploration lease (EL5842) of about 204km2, surrounds the mining
tenements and extends to the south from the Barrier Highway for approximately 34 km sub-parallel
to the Canbelego-Nymagee Road (Figure 3.2).
In addition, Polymetals applied for a mining lease (MLA 281, area 188 ha) on the 4th May 2006, that
extends to the west and south of the existing mining leases (ML) and gold leases (GL) covering
Mount Boppy (Figure 3.1). The MLA is the subject of a native title agreement which was signed in
late October, 2010, allowing the mining lease to be granted in the near future. The granting of this
MLA will remove depth restrictions on MLP 240 and ML 311.
Table 3.1
Canbelego tenements
Tenement
Holder
Grant date
Expiry date
Area [ha]
GL5836
Polymetals (Mt Boppy) Pty Ltd
15 Jun 1965
15 Jun 2012
6.045
GL5898
21 Jun 1972
21 Jun 2013
7.512
ML311
08 Dec 1976
21 Jun 2013
10.117
MPL240
17 Jan 1986
21 Jun 2013
17.8
GL3255
20 May 1926
20 May 2012
8.281
GL5848
15 Feb 1968
15 Jun 2012
8.625
EL5842
19 Apr 2001
19 Apr 2011 – renewal pending
74 units
#
# one unit equals approximately 300 ha
GL – Gold Lease, ML- Mining Lease, MPL – Mining Purposes Lease, EL - Exploration Lease
Mount Boppy is located 5 km south of the Barrier Highway along the Canbelego-Nymagee road. The
Barrier Highway is the major sealed road linking Cobar to Broken Hill in the west and Dubbo and
ultimately Sydney in the east. The Canbelego-Nymagee road provides the primary access to the
exploration prospects located within EL5842. After leaving the Canbelego-Nymagee road, access
relies on various station tracks.
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Figure 3.1
Location of Polymetals' Canbelego mineral leases, gold leases and mining lease application
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Figure 3.2
EL5482 located around the Canbelego mining tenements
The project area has a semi-arid climate with hot summers and cool to mild winters. It has a median
annual rainfall of 390 mm. Rainfall is extremely variable, particularly in late summer and early
spring.
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The area is dominantly composed of isolated low-lying hills and ridges separated by wide valleys,
typical of the Cobar district. The ridges are generally low, north-trending and the hills are covered
with eucalyptus woodlands (Figure 3.3 and Figure 3.4). The broad valleys are covered by woodlands
and grasslands.
Figure 3.3
View from top of Mount Boppy looking southeast towards mine site
Figure 3.4
View north-west from mine site with pit west wall ramp in foreground and Mount Boppy in
background
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3.2.
GEOLOGICAL FRAMEWORK
3.2.1.
REGIONAL GEOLOGY
The Canbelego Project lies within the Cobar region of the Palaeozoic Lachlan Orogen in eastern
Australia. The Lachlan Orogen comprises four tectono-stratigraphic terranes: south-western
Lachlan, western Lachlan, central Lachlan and eastern Lachlan. The central Lachlan terrane hosts the
Cobar region, which lies between two major fault systems; the Gilmore Suture-Indi fault zone to the
east and the Koonenberry-Kiewa fault system to the west.
The geology of the Cobar region comprises Ordovician basement, Silurian-Devonian basin fill and
Devonian post-orogenic cover.
The Ordovician basement comprises arenitic to pelitic
metasediments intruded by Silurian granites. The geology of the Silurian-Devonian Cobar Basin is
characterised by flanking shelfs on the margins of deep-water troughs (Kopyje Shelf and Winduck
Shelf), intrabasinal shelves, volcanoclastic-siliciclastic troughs and the volcanic Canbelego-Mineral
Hill Rift Zone (Figure 3.5), which is host to the Canbelego Project, including the Mount Boppy Mine.
The Devonian Canbelego-Mineral Hill Rift Zone developed between the eastern Cobar Basin margins
and Gilmore Suture. The rift zone forms a graben system comprised of a basal conglomerate
overlain and interlayered with a sequence of felsic tuffs, dacite and rhyolite flows/dykes and lapilli
tuffs. In the central part of the basin, intermixed sandstones and siltstones occur with localised
outcrops of fossiliferous limestone. The rift is bounded to the east by the reactivated Coonara Fault
and to the west by the reactivated Burra Fault.
3.2.2.
LOCAL GEOLOGY
The Canbelego Project is located in the northern part of the Canbelego-Mineral Hill Rift Zone. Gold
mineralisation occurs within the Ordovician basement (Girilambone Group) and the Devonian cover
(Baledmund Formation). Mineralisation hosted in the Baledmund Formation is characterised by a
variety of gold and base metal occurrences usually hosted in shear zones at the boundary between
rocks of contrasting competency (e.g., tuffs and siltstone, tuffs and massive rhyolite). The best
examples of this style are located at the Pipeline Ridge and Glens Hill prospects on Polymetals'
EL5842 (Schifano and Burell, 2009; Figure 3.6). Other mining projects in the Cobar region are
summarised by Figure 3.7.
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Figure 3.5
Tectono-stratigraphic units of the Cobar Basin, with the Canbelego Project being located in the
northern extremity of the Canbelego-Mineral Hill Rift Zone
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Figure 3.6
Exploration prospects on exploration licence EL5842
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Figure 3.7
Regional mine and resource overview in the Cobar region of NSW
MOUNT BOPPY
At Mount Boppy, the Main Lode is a quartz vein system developed along a normal west-dipping fault
which down faults the Baledmund Formation rocks on its western side against Girilambone Group
rocks on its eastern side (Harvey, 2005a). The Main Lode strikes approximately north-south and dips
at approximately 80° west; however, it shows considerable variation in strike and dip (Figure 3.8).
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Figure 3.8
Mount Boppy local geology and drill hole locations
The West Lode is developed along the West Lode Fault, which truncates the Main Lode. The West
Lode Fault displaces the Girilambone Group phyllite on its western side against the sericitic siltstones
of the Baledmund Formation on its eastern side. The displacement along the West Lode Fault is
difficult to determine but is interpreted as largely lateral with some vertical displacement.
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The West Lode has a width of about 1 m to 2 m and is largely a fault breccia made up of fragments of
phyllite, sericitic siltstone and quartz. It also contains quartz vein material that cuts across the fault
breccia. Gold grades within the West Lode are best developed in the area south of, and near its
intersection with, the Main Lode.
The West Boppy Lode also lies on a faulted contact between Baledmund Formation and Girilambone
Group (West Boppy Lode Fault). Outcrop is poor and the lode has an apparent width of less than
one metre. The lode is comprised of quartz and it is similar to that within the Main Lode. The West
Boppy Lode has an apparent strike length of about 600 m.
The configuration of the faults and lodes at the Mount Boppy Gold Mine leads to the interpretation
that the West Boppy Lode is the faulted northern extension of the Mount Boppy Main Lode (Figure
3.8). The faulting has apparently occurred along the West Lode Fault. This interpretation provides a
target for exploration at Mount Boppy called the ‘Main Lode Faulted Northern Extension Target'.
3.3.
MINERALISATION
The geology and mineralisation exposed at Mount Boppy Mine and nearby prospects is consistent
with that of gold-rich deposits within a polygenetic Cobar-style model, as proposed by Stegman
(2000). Cobar-style deposits are epigenetic, syn-tectonic, structurally controlled and dominated by
copper-gold mineralisation, which is at least partly remobilised (Glen, 1987; Lawrie and Hinman,
1998; Stegman, 2001).
Mount Boppy and adjacent gold prospects display features typical of this mineralisation style, e.g.,
epigenetic lodes highly discordant to the stratigraphy. Additionally, they are related to early
Devonian basin inversion, a geological criteria for Cobar-style mineralisation (Lawrie and Hinman,
1998). The presence of a regional foliation that cross-cuts the mineralisation is evident (Allen, 2003),
indicating that shearing and thrusting took place after the main phase of mineralisation.
Mineralisation at Mount Boppy is hosted by brecciated, highly silicified, fine-grained sediments of
the Devonian Baledmund Formation (Figure 3.9) and associated quartz veins. The mineralisation
consists predominantly of gold with minor zinc, copper and lead.
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Figure 3.9
Brecciated ore at Mount Boppy, drill hole PMS123 at 109.4 m
3.4.
EXPLORATION AND MINING HISTORY
3.4.1.
MOUNT BOPPY
Gold was first discovered in the general Canbelego area in 1889. In 1897, the Anglo-Australian
Exploration Company purchased a number of leases in the area. In 1899, the company floated the
Mount Boppy Gold Mining Company in London to work the deposit but major production did not
commence until 1901 owing to a scarcity of water caused by drought. Gold production at Mount
Boppy commenced from an underground mining operation and continued to 1923 (Figure 3.10). In
its day, the mine was one of the largest gold producers in Australia. The orebody delivered some
417,000 ounces gold at a notional head grade of 15 g/t gold (12.2 g/t gold recovered). Sporadic
operation up to 2002 added a further 7,000 ounces of gold production. This included gold recovered
from the first Carbon-In-Pulp (CIP) plant built in Australia in 1975 at Mount Boppy to re-treat the
historic tailings.
Polymetals re-opened the Mount Boppy Mine in 2002, establishing open cut operations over the
historic underground mine. The operations produced 67,855 ounces from 503,418 t of ore between
2002 and mine closure in 2005 when the lease configuration limited further pit development and a
larger mining lease application was delayed by native title issues. The Mount Boppy Mine and its
150,000tpa gold processing plant are currently on care and maintenance. Polymetals plans to add to
the mining inventory of 560,000 t at 5.14 g/t gold by delineating additional high-grade ore sources
before committing to re-commencing mining.
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Figure 3.10
Gold production from the Mount Boppy mine and timing of some events affecting production
rates, from McQueen (2005)
Polymetals' exploration at Mount Boppy has focussed largely on depth extensions below and around
the existing pit. This process was guided by an interpretation of structural controls on the
mineralisation from a ground magnetic survey completed on the mining leases in 2003 (Allen, 2003).
Northern extensions of the open pit were drill-tested in 2003 (Allen, 2003). Although alteration and
minor gold grades were intersected, no potential ore was outlined. Polymetals reassessed the
geological interpretation in 2005 (Harvey, 2005a) leading to further RC and diamond drilling under
the Mount Boppy pit and West Boppy (Harvey, 2005b). The drilling demonstrated the presence of
mineralisation, which apparently plunges shallowly to the south, to a depth of approximately 140 m
below the natural surface topography and approximately 80 m below the deepest parts of the
existing pit.
Preliminary design work has been completed based on the concept of deepening the existing pit.
This includes a geotechnical review by Coffey Mining (Fuller, 2006).
Small work programmes were conducted around the mining lease, focussing on a number of minor
historical workings. The best potential was considered to be associated with the Birthday Prospect
which is located within EL5842 approximately 1 km to the southeast of the Mount Boppy pit (Allen,
2003). RC drilling at Birthday by Golden Cross in 2004 (25-holes for 1,666 m) intersected gold
mineralisation in several drill holes, including 5 m averaging 39.8 g/t gold, 12 m averaging 1.11 g/t
gold and 2 m at 3.45 g/t gold (holes GCB030, GCB032, GCB037 respectively).
Other prospects include Boppy South, which is located approximately 500 m south of the Mount
Boppy Mine, where epithermal quartz veins yielded gold grades of 16.4 g/t gold and 27.6 g/t gold
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from grab samples was reported by Golden Cross Resource Ltd (GCR 2002). An RC drilling
programme by Polymetals in 2003 (23 holes for 1,378 m) intersected gold mineralisation in several
drill holes, including 7 m at 3.70 g/t gold (SB006), 3 m at 10.81 g/t gold (SB009), 5 m at 4.98 g/t gold
and 8 m at 5.26 g/t gold (SB017).
A number of encouraging gold intercepts were also obtained from drill holes immediately south of
Mount Boppy pit on ML 311. Polymetals holds this mining lease to cater for tailings or dump
impoundments. ML 311 is depth restricted to 3 m; the ground beneath the lease is part of EL5842
which is owned by Polymetals but was previously owned by Golden Cross Operations, a wholly
owned subsidiary of Golden Cross Resources Ltd (Golden Cross). The intersected gold mineralisation
suggests that the structure being mined in the pit continues to the south.
Polymetals applied for a mining lease (MLA 281, area 188 ha) on the 4th May 2006 which extends to
the west and south of the existing mining leases (ML) and gold leases (GL) covering Mount Boppy.
This MLA extends under the depth-restricted ML 311 and MPL 240 leases (Figure 3.1). Once
granted, the ML will remove any depth restrictions to future cut backs of the existing Mount Boppy
pit designed to access deeper resources. The MLA was subject to a native title claim with the
Ngiyampaa people, however, a native title agreement is now signed and has been submitted to the
NSW I&I which should allow approval of the lease in early 2011.
3.4.2.
EXPLORATION LEASE EL5842
A number of companies have explored the Canbelego area since 1961. Exploration activities
intensified after the discovery of the Pipeline Ridge prospect (Figure 3.6) by Mines Exploration Pty
Ltd in 1974. Between 1973 and 1979 Mines Exploration conducted both mapping and drilling at
Pipeline Ridge, but also at Glens Hill (Figure 3.6) and completed several geophysical surveys including
electromagnetics (EM), magnetics, gravity and induced polarisation (IP).
In the 1980s companies including Amoco Minerals Australia Company, Homestake Australia Ltd and
Cyprus Gold Australia Corporation explored Pipeline Ridge and Glens Hill further and conducted
several drilling campaigns in the area. Soil sampling was also carried out at Pipeline Ridge and Glens
Hill in the early 1990's by Arimco NL and Timmsco Pty Ltd (which later became Golden Cross
Operations Pty Ltd).
Between 1994 and 2008 exploration activities across the lease were managed by Golden Cross. At
Pipeline Ridge, exploration included RC drilling to test supergene oxide gold and base metal
mineralisation. Additionally, minor diamond drilling was conducted to test deeper sulphide
mineralisation. The drilling delineated multiple auriferous zones of two to ten metres width with
minor silver, copper, lead and zinc occurrences over a strike length of approximately 500 m (Figure
3.11). The mineralisation appears to be intrusive-related and lies in the footwall portion of a fault
where extensive brecciation has taken place.
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Figure 3.11
Pipeline Ridge cross section showing drill hole intercepts and interpreted geology
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During the same period, exploration generated a number of other prospects shown in Figure 3.6
including:
Hardwick's (gold)
Reid – Rankin’s (gold)
West Kopyje (gold)
Kopyje (lead, zinc and arsenic)
Bullseye Anomaly (gold)
Native Dog (silver, arsenic and antimony).
Drilling at Hardwick’s by Golden Cross in 2005 (17 RC holes for 590 m) intersected gold
mineralisation including 3 m averaging 15.94 g/t gold, 6 m averaging 2.78 g/t gold, 6 m at 1.47 g/t
gold and 4 m at 3.25 g/t gold (holes GCB088, GCB090, GCB091 and GCB116 respectively).
In late 2008, Polymetals purchased the EL5842 tenement. In 2009, Polymetals completed a high
resolution ground magnetic survey around the Mount Boppy Gold Mine. The interpretation of this
data identified a structure similar to those observed/interpreted at the current mine site (Jones,
2010). Jones named this area the 'Racecourse' prospect and recommended further exploration,
including deep RC drilling with diamond core tails. A fault in the area appears to be a splinter of the
main Mount Boppy structure, and marks a discontinuity between the Baledmund Formation and
Girilambone Group as at the Mount Boppy Mine.
Polymetals has undertaken a review of the digital data and reports acquired from Golden Cross
when the exploration lease was acquired. This process is ongoing and is allowing Polymetals to
prioritise the exploration of the many exploration targets that are present on the lease.
3.5.
MINERAL RESOURCES
The Mineral Resource estimate for the Mount Boppy Gold Mine was completed in late 2008 based
on exploration and grade control data. The area covered by the resource estimate extends for
500 m along strike, 300 m across strike and to 140 m below the original topography surface. Optiro
has reviewed the resource model and considers the Mineral Resource estimate to have been
compiled and reported in accordance with the JORC Code (2004). The Mineral Resource defined
below the existing Mount Boppy pit is presented in Table 3.2 and distinguishes between in situ
resources and the estimated stope backfill resource.
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Table 3.2
Mount Boppy Mineral Resource estimate, 2008
Mount Boppy Mineral Resource 2008 reported above a 2.5 g/t gold lower cut-off grade
Tonnes [t]
Gold grade [g/t]
Contained metal
[oz gold]
Measured (in situ)
30,000
5.0
4,800
Indicated (in situ)
45,000
4.5
6,500
Indicated (stope fill)
195,000
3.6
22,600
Measured + Indicated Total
270,000
3.9
33,900
Inferred (in situ)
365,000
4.6
54,000
Category
Optiro notes that there is no evidence of QAQC practice at Mount Boppy. This omission is believed
to reflect the private ownership status of the operation during the last mining phase. However,
results of independent sampling conducted by Optiro at Mount Boppy mine in May 2010, together
with past production from the mine, confirm the presence of gold grades that are potentially viable
for future mining.
Polymetals applied a top-cut of 30 g/t gold based on gold grade statistics. Bulk density values were
assigned to both in situ mineralisation and stope backfill based on the experience gained from
mining within the pit and results obtained from drill holes. Fresh rock was assigned a density of
2.7 t/m3, oxidised rock a density of 2.2 t/m3 and stope backfill a density of 1.5 t/m3, which Optiro
considers appropriate. In addition, Polymetals assigned an average grade of 3.6 g/t gold to the stope
backfill based on the average grade obtained from blast hole sampling of backfill.
Gold grades were estimated into the mineralisation solids using ordinary kriging and multiple passes
with increasing sample search ranges to inform all blocks. However, even with the application of
multiple search passes, a considerable, but unquantified portion of the interpreted mineralisation
did not receive a grade estimate and was excluded from further calculations (Figure 3.12). This
volume represents potential upside to the Mineral Resource if additional drilling confirms its
presence.
Polymetals categorised the in situ mineralisation with an estimated gold grade as Measured,
Indicated or Inferred Mineral Resource based on the search pass that informed the estimate (Figure
3.12). Higher confidence blocks were those informed by shorter range searches. The stope backfill
was categorised as an Indicated Mineral Resource.
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Figure 3.12
Mount Boppy Mineral Resource relative to existing pit limit (long axis of pit at rim is 400 m)
Polymetals' reconciliation indicates a good comparison between the resource estimate's prediction
and the actual outcome in parts of the resource model informed by close spaced blast hole data.
While it should not be anticipated that the rest of the estimate will be as accurate, as it is based on
more widely spaced exploration drill holes, the comparison does suggest that the blast hole data
does not suffer from significant sampling bias and that it was valid to include it in the resource
estimation process.
It is Optiro's view that the principal risks associated with the Mount Boppy Mineral Resource, as
presented in Table 3.2, are the uncertainty associated with the large portion of the resource
categorised as Inferred and the large portion of the Indicated Mineral Resource derived from stope
backfill.
3.6.
MINING AND PROCESSING CONSIDERATIONS
The Mount Boppy Gold Mine was operated by Polymetals between 2002 and 2005. Material was
mined from two pits referred to as Pit 1 (north) and Pit 2 (south) that are conjoined. Ore from these
two pits was derived from remnant material from historical underground workings including backfill
sands, as well as in situ material.
The plant performance generally improved over the life of the operation, as noted by the decreasing
tail grades from 2002 to 2004. In 2005, Pit 2 was processed resulting in a change in ore
characteristics, most notably a visual increase in sulphide minerals. Whilst recoveries for 2005 were
in line with previous years, tail grades increased significantly with head grade increases (Table 3.3).
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Table 3.3
Year
Summary of the plant performance at Mount Boppy, from Lawry (2010)
Tonnes milled [t]
Gold grade [g/t]
Head
Tail
Gold recovery [%]
Comments
2002
101,765
3.24
1.05
67.6
Surface tails and start-up
2003
145,854
5.58
1.00
82.1
Pit 1 processed
2004
126,993
3.95
0.73
81.4
Pit 1 completed (December)
2005
128,806
7.91
1.61
79.6
Pit 2 processed
Total
503,418
5.29
1.10
79.2
Polymetals reconciled the initial unclassified mine inventory against the processed tonnes and mined
grades (from grade control drilling). The initial unclassified mine inventory was derived from
Polymetals' in-house estimates and was not reported.
The reconciliation indicated the following:
More ore was mined than was anticipated in the Ore Reserve. This was thought to be due to
the presence of backfill sands (difficult to model) and some low-grade ore that occurred
outside of the model.
The final mined grades reported were lower than anticipated, again due to sands and lowgrade material.
More contained gold was mined compared to the mine inventory.
3.7.
EXPLORATION POTENTIAL
The Canbelego Project is at an advanced stage of exploration and development. The orebody at
Mount Boppy has been mined in the past, with the mine currently under care and maintenance.
Depth and strike extensions of the orebody have been identified and will be drill-tested in the
future.
Of particular interest is the area immediately south of the Mount Boppy pit, which only became
available for exploration at depth through the acquisition of exploration licence EL5842. Previous
gold intercepts suggest that the structure being mined in the Mount Boppy pit continues to the
south.
Additionally, several near-mine opportunities have been identified over decades of exploration,
including the recent identification of the Racecourse anomaly. However, these near-mine targets
require further work before their resource potential can be evaluated fully.
Favourable lithologies for mineralisation occur throughout EL5842. Several gold prospects have
been identified including Hardwick’s, Birthday, Boppy South, Pipeline Ridge, Reid-Rankin’s, Bullseye
anomaly and West Kopyje. These prospects, which are located up to 25 km away from the Mount
Boppy mine, could potentially provide additional ore for the processing plant at Mount Boppy.
However, most of these prospects are at an early to moderate exploration stage only and require
additional work.
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4. DREW HILL
4.1.
The Drew Hill Project is located approximately 30 km north-east of the village of Olary in South
Australia and 85 km west of the regional centre of Broken Hill in New South Wales. Access is via the
Barrier Highway and station tracks.
The nearest settlement is Olary, while Broken Hill is the nearest major town. Broken Hill has been a
major mining centre since 1883, and provides a skilled workforce to the operation.
The Drew Hill Project, including the recently opened White Dam Mine, is jointly owned by Exco
Operations (SA) Ltd (Exco), which owns a 75% interest and Polymetals which owns the remaining
25% interest. The Drew Hill Project is located on a contiguous block comprising a single mining lease
(ML), five miscellaneous purpose licences (MPL), a single mineral claim (MC) and four exploration
leases (EL) (Figure 4.1 and Table 4.1). The White Dam Gold Mine, which was officially opened in June
2010, is located on ML6275. The mine infrastructure is located on MPL106 (Figure 4.1).
Table 4.1
Drew Hill tenements
Tenement
Holder
Grant date
Expiry date
Area [ha]
MPL095
Exco Operations (SA) Ltd (75%); Polymetals
(White Dam) Pty Ltd (25%)
11 Sep 2007
10 Sep 2014
24
MPL104
24 Jan 2008
23 Jan 2015
250
MPL105
24 Jan 2008
23 Jan 2015
250
MPL106
24 Jan 2008
23 Jan 2015
163
MPL107
24 Jan 2008
23 Jan 2015
132
MC4193
Pending in March 2011
Pending
250
ML6275
11 Sep 2007
10 Sep 2014
250
#
#
EL4200
*
Exco Operations (SA) Ltd
Renewal lodged 7 Oct 2010
Pending
22,900
EL4321
*
Renew lodged 8 Sept 2010
Pending
9,600
EL4199
*
Renewal lodged 7 Oct 2010
Pending
4,900
28 Jul 2010
27 Jul 2012
34,300
*
EL4533
Exco Operations (SA) Ltd, Exco Resources
(SA) Pty Ltd
MPL - Miscellaneous Purpose Licence, ML - Mineral and Special Mining Lease, MC - Mineral Claim, EL - Exploration Lease, ELA - Exploration
Lease Application
#
MPL104 and MC4193 cover the same area
*
Transfer of 25% to Polymetals (White Dam) Pty Ltd registered 2 Dec 2010 but not yet approved
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The mining activities at White Dam operate under the 'White Dam Gold Production JV', managed by
Polymetals, whilst the exploration activities at Drew Hill operate under the 'Drew Hill Exploration JV',
managed by Exco.
Figure 4.1
Location of the Drew Hill tenements
The nearest weather recording station to the Drew Hill Project is at Yunta, located some 110 km to
the south-west along the Barrier Highway. Mean monthly maximum temperature at Yunta ranges
from 15.4°C in July to 32.6°C in January. Mean monthly minimum temperatures at Yunta range from
3.0°C in July to 15.0°C in January. Average annual rainfall at Yunta is 236 mm.
The Drew Hill Project is located within a landscape of subdued topography and limited bedrock
exposure. The area is within the upper Mingary Creek catchment, which is a part of the Lake Eyre
Basin. The Mingary Creek flows into the Strzelecki Desert dune-field south of Lake Frome.
The vegetation is defined as a chenopod scrubland, dominated by bladder saltbush, black bluebush,
and minor pearl bluebush. Occasional rosewood trees occur near bedrock exposures and regolith
carbonate accumulations, while she-oak occurs on some alluvial plains and alluvial fans (Figure 4.2).
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Figure 4.2
Drilling and vegetation at Drew Hill
4.2.
4.2.1.
REGIONAL GEOLOGY
The Drew Hill Project is located in the Olary Domain of the Curnamona Craton (Figure 4.3). The
Olary Domain is composed of lower Proterozoic rocks from the Willyama Supergroup, which is
subdivided into three major units; the Curnamona Group at the base, overlain by the Saltbush
Group, and the Strathearn Group at the top (Conor et al., 2006).
The Curnamona Group comprises mainly variably oxidised, strongly magnetic gneisses and schists,
whereas the overlying weakly magnetic Saltbush Group is dominated by metapelites that are
chemically mostly reduced. Their mutual contact is an important redox boundary (Figure 4.4),
marked by a prominent magnetic anomaly that in the Olary Domain has served as the locus for
several recently discovered mineral deposits (e.g., Kalkaroo, White Dam, Portia).
The Willyama Supergroup was intruded by syn- to post-orogenic granites, pegmatites, and by maficultramafic dykes and plugs that postdate high-grade metamorphism (Page et al., 2005) related to the
Mesoproterozoic Olarian Orogeny.
The Olary Domain was reworked again during the Cambrian Delamerian Orogeny. Extensive
reactivation of pre-existing fault and shear zones and mid-pressure, mid-temperature
metamorphism attaining kyanite-garnet-staurolite assemblages destroyed much of the earlier highgrade metamorphic assemblages.
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Figure 4.3
Geological domains of the Curnamona Province
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Figure 4.4
Geological framework showing the regional redox boundaries in the southern Curnamona
Province, modified after Leyh and Conor (2000)
4.2.2.
LOCAL GEOLOGY
The Drew Hill tenements comprise deformed albitised pelitic schists, calc-silicate schists and gneisses
of the lower Willyama Supergroup (Curnamona Group), intruded by younger granites (Bimbowrie
Suite). Geological understanding of the White Dam project area is hindered by the lack of outcrop,
as most of the area is covered by a thin layer of regolith. Magnetic images have been used in
conjunction with drilling results on both regional and prospect scales to interpret the geology of the
White Dam area (Figure 4.5).
Five units, representing the lower part of the Curnamona Group, occur in the White Dam area. The
basal unit is a quartz-feldspar gneiss which is overlain with a package of biotite-muscovite gneiss and
inter-layered biotite-sillimanite schist. The main mineralisation is confined to the biotite-muscovite
gneiss but minor mineralisation is also hosted in the overlying massive gneiss and leucocratic banded
gneiss. The overlying calc-albitites and calc-silicates represent the Peryhumuck Formation of the
upper Willyama Supergroup (Saltbush Group) with the calc-albitites forming the majority of outcrop
in the project area.
Although most units are complexly folded, there is a general east-west strike with a northerly dip.
The structures are related to both the Olarian and Delamarian Orogenies and are strongly evident
within the project area.
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Figure 4.5
Interpreted geology at White Dam over aeromagnetic image, after Bargmann (1999)
4.3.
MINERALISATION
Stratabound epigenetic copper-gold-molybdenum mineralisation is widespread in the lower parts of
the Willyama Supergroup. These deposits are located regionally at the transition from older,
oxidised (magnetite-rich) rocks to younger, reduced metasedimentary rocks near the upper and
lower Willyama Supergroup boundary (Page et al., 2005). Major prospects associated with this zone
are at Walparuta, Dome Rock Mine, Waukaloo, Burdens Dam, White Dam, Kalkaroo and Benagerie Portia (Figure 4.4).
The Drew Hill Project comprises five main gold prospects, from north to south: White Dam North,
White Dam (including the White Dam Mine), White Dam South, Vertigo and Ambush (Figure 4.8).
4.3.1.
WHITE DAM
The White Dam deposit constitutes the principal resource within the Drew Hill Project. Gold
mineralisation is hosted by open folded sub-horizontal quartzo-feldspathic biotite-bearing
migmatitic gneisses (Figure 4.6) with abundant pegmatites.
The White Dam gold resource sits within an extensive stockwork of predominantly pyritechalcopyrite veins with associated copper and molybdenum. The deposit style has many similarities
to other Proterozoic iron-copper-gold deposits, except that in this case iron is within biotite rather
than as iron oxide minerals. Compared with other gold-copper prospects in the district, White Dam
has a relatively low iron content and does not show elevated levels of arsenic, silver, nickel,
cadmium, antimony or lead (Cordon, 1998).
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The low-grade White Dam gold Mineral Resource is interpreted as a sub-horizontal supergene or
disseminated blanket (Figure 4.7) formed around narrower zones of steeply dipping higher grade
primary gold mineralisation. Sulphide minerals at White Dam are completely oxidised up to 50 m
below the surface (Figure 4.7), with an asymmetric weathering profile that is deepest close to a
major north-trending fault that appears to control the groundwater circulation. Within this zone,
copper has leached downward to form a supergene blanket within the transition zone, with mineral
types dominated by chalcocite and copper silicates. In the oxide zone, gold has been remobilised
onto biotite with minimal transport from its origin, with gold concentrated in biotite-rich selvedges
and leucocratic bands and veins within the gneiss. Fine gold has grown onto biotite surfaces, which
accounts for the small amount of visible gold and the excellent leach characteristics that allow rapid
dissolution and high recovery of gold by cyanide leach.
Higher grade mineralised zones are spatially associated with syn-tectonic pegmatites, with sulphide
veins both adjacent to and cross-cutting pegmatites. Mineralised veins and pegmatites are
commonly parallel to gneissic layering on north-dipping fold limbs, whereas on south-dipping limbs
the veins form irregular stockworks.
Figure 4.6
Banded biotite-altered gneiss from the White Dam orebody
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Figure 4.7
Long section of the White Dam deposit at line 6,449,000 mN
4.3.2.
WHITE DAM NORTH
The White Dam North prospect is located approximately 800 m to the north of the White Dam Mine.
White Dam North is a large soil geochemical gold anomaly, which has been tested during several
drilling campaigns in recent years, returning significant gold intercepts in several holes (Table 4.2).
Table 4.2
Significant gold intercepts from the 1998 and 2010 drilling programmes at White Dam North
Year
2010
Hole
Intercept [m]
Gold grade [g/t]
Depth from [m]
WDN02
24
0.53
24
including
6
0.81
24
WDN05
12
0.54
18
WDN06
12
0.68
24
including
6
0.97
24
WDN11
6
0.27
42
WDN33
6
0.55
12
WDN34
6
0.29
30
4
1.08
53
5
0.55
68
4
0.52
29
7
0.76
26
6
2.57
42
6
0.59
74
WD171
1998
WD173
WD174
WD175
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4.3.3.
WHITE DAM SOUTH
White Dam South is located along the southern continuation of the western bounding fault of the
White Dam deposit. In addition to the obvious favourable structural setting, the target area also
comprises favourable lithologies. Strongly magnetic albitites on the eastern side of the fault are in
(faulted) contact with weakly magnetic gneisses and schists to the west.
The area has not yet been extensively explored, however, drilling carried out in 2010 achieved only
limited success and no further work is planned at this target in the near future.
4.3.4.
VERTIGO
The Vertigo prospect is located approximately 1 km south-west of the White Dam Mine. This
prospect was drilled in 2003, 2007 and 2010, resulting in a recent (late 2010) geological
interpretation and mineral resource estimate. Significant gold intersections are shown in Table 4.3.
Table 4.3
4.3.5.
Significant gold intercepts of the 2010 drilling programme at Vertigo
Hole
Intercept [m]
Gold grade [g/t]
Depth from [m]
VG135
22
0.82
0
including
12
1.21
10
VG136
4
0.33
22
VG142
2
0.24
16
VG143
6
0.43
2
VG144
6
0.40
6
including
2
0.69
8
AMBUSH
The Ambush prospect is located approximately 2 km south of the Vertigo prospect.
MIM identified a strong discrete soil anomaly over the Ambush prospect in 1998. Limited drill
testing in 2003 yielded only one drillhole returning a value in excess of 0.2 g/t gold (hole AMB7). It is
believed that these holes did not sufficiently test the structural and stratigraphical setting coupled
with a strong geochemical anomaly. Drilling was conducted in 2010 and follow-up work is planned
in 2011.
4.4.
Gold exploration in the area is reported from 1988. This targeted gold-copper mineralisation
associated with silica-magnetite units.
In 1994 and 1995 MIM Exploration Pty Ltd (MIM) recognised the regional potential for gold-copper
mineralisation in well-exposed prospects south of the Drew Hill area. Since that time, a considerable
amount of exploration has been conducted at the Drew Hill Project and its surroundings (Figure 4.8).
Initial work targeted magnetic anomalies at White Dam, where soil sampling outlined a gold-copper
anomaly. RC holes were drilled across the defined soil anomaly in 1996 and 1997 reporting grades
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of 1.21 g/t gold from a depth of 4 m to 44 m as well as 42 m at 2.8 g/t gold from 4 m. Further RC and
diamond drilling evaluated areas away from the soil anomaly, intersecting both oxide and sulphide
gold mineralisation, confirming a substantial body of stratabound gold-copper mineralisation within
banded biotite-rich leucocratic gneiss.
In 1997 and 1998 MIM conducted geophysical surveys, including induced polarisation (IP), ground
magnetics, electromagnetics (EM), and radiometrics at the White Dam prospect and generated a
bedrock geology map.
Geochemical soil surveys, as well as IP and gravity surveys were completed over the Matrix and
Vertigo prospects in 1999. The Ambush prospect was covered by soil survey in 2000 and
subsequently drill-tested.
Figure 4.8
Historical and recent drilling work at prospects in the Drew Hill area
The White Dam deposit has undergone extensive drilling work in the past 13 years including
resource definition and percussion drilling plus production grade control drilling. Additionally,
diamond drilling was carried out for geotechnical strength testing and metallurgical test work.
Work completed by Exco during the 2003 reporting period included establishing a project database
and conducting preliminary resource modelling. This was followed by site works including a sixcostean programme to constrain the geological model, for grade-control, and to provide bulk
samples for further metallurgical test work. Excavations were geologically mapped and sampled. In
addition, bulk samples were taken from the material removed during excavation of the trenches to
provide material for heap leach test work. During late 2003 and 2004, regional exploration was
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conducted, focussing on geochemical and magnetic targets identified from a desktop review
completed by Exco. During 2004, Exco completed three drilling programmes.
Regolith and landforms in the White Dam area were mapped in 2004 (Lau, 2004). The regolith
landform map delineated subtle yet significant changes in regolith and landforms over known
mineralisation and adjacent areas.
In 2005, Exco and Polymetals jointly completed two drilling programmes for a total of approximately
2,275 m. The first programme was aimed at identifying suitable water supply volumes in the local
area around the White Dam deposit. The second campaign, completed in 2006, was aimed at
expanding the resource to the east at the White Dam deposit and to follow up on mineralisation
identified at the White Dam North and Vertigo prospects.
In 2006, Exco mainly focussed on further advancing its White Dam Project by completing flora and
fauna surveys, and in December 2006 commissioned Allsurv Engineering Surveys to generate a
topographic map of the White Dam area.
Full 3D interpretation wireframes of the mineralisation were completed on the White Dam gold
deposit in 2004, which were subsequently modified based on new drill data. The most recent
geological interpretation of the White Dam orebody has been carried out by Polymetals and Exco in
2010, which resulted in an updated Mineral Resource estimate (Table 4.4).
4.5.
MINERAL RESOURCES AND ORE RESERVES
While undertaking an inspection of the White Dam mine and nearby Vertigo deposit, Optiro held
meetings with Polymetals’ mine production personnel, including the General Manager and Senior
Mine Geologist. A brief review was conducted of the digital data supporting the White Dam Mineral
Resource estimate and the grade control models used for ore and waste delineation in the pit.
It is Optiro's view there is sufficient evidence that industry standard quality control practices have
been employed during the collection of the exploration data supporting the exploration prospects
and Mineral Resources comprising the Drew Hill Project.
Optiro collected a number of independent check samples during its site visit in May 2010. The gold
grades obtained from these samples are considered to be consistent with expectations from the
style of mineralisation at White Dam.
4.5.1.
WHITE DAM
The White Dam Mineral Resource was estimated in December 2010 based on the results of drilling
carried out up to October 2010, including:
resource infill drilling on a nominal 25 m by 25 m pattern
grade control drilling to approximately 20 m vertical depth on a nominal 12.5 m by 12.5 m
pattern.
The resource has been estimated using an ordinary kriging grade interpolation methodology. The
closely-spaced shallow infill drilling has allowed almost all of the oxide material resource to be
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classified as Indicated (Table 4.4). Optiro considers this classification to be conservative, inasmuch
as some of the reported tonnage could probably be assigned to a higher confidence Measured
Mineral Resource category, but otherwise endorses the classification. The White Dam Mineral
Resource, reported in Table 4.4, has been depleted for mining up to the end of September 2010.
Table 4.4
Combined White Dam and Vertigo ordinary kriging (OK) mineral resource estimate using a cutoff grade of 0.3 g/t gold for White Dam and 0.4 g/t gold for Vertigo, from Exco (2011a and
2011b)
Mineral Resource Category
Vertigo
White Dam
Project
Indicated
Material
Inferred
Tonnes [kt]
Gold grade
[g/t]
Metal [oz]
Tonnes [kt]
Gold grade
[g/t]
Metal [oz]
Oxide
3,604
1.07
124,000
100
0.74
2,400
Fresh
341
1.03
11,300
1,954
0.88
55,300
Sub-total
3,944
1.07
135,200
2,054
0.87
57,700
Oxide
1,008
1.10
35,600
703
0.73
16,500
Fresh
212
1.56
10,600
526
1.15
19,400
Sub-total
1,220
1.18
46,200
1,229
0.91
35,900
5,164
1.09
181,400
3,282
0.89
93,600
Project Total
Note: Individual columns of data may not add up due to rounding. White Dam Mineral Resource depleted by mining to the
end of September 2010. Ms Christine Shore, a full time employee of Exco Resource Ltd is the Competent Person for the
White Dam Mineral Resource. Mr Lauritz Barnes, a consultant to Exco Resource Ltd from the Mitchell River Group, is the
Competent Person for the Vertigo Mineral Resource.
4.5.2.
VERTIGO
The Vertigo Mineral Resource was estimated in January 2011 and resulted in a substantial portion of
the deposit being upgraded to an Indicated Mineral Resource based on drilling completed in late
2010 (Table 4.4). The newer drilling resulted in the deposit being tested by a combination of 25 m
by 25 m and 25 m by 50 m drillhole spacings. The 25 m by 25 m drilling supports the Indicated
classification of part of the Mineral Resource. Optiro endorses this resource categorisation. A total
Mineral Resource of 2.45 Mt at 1.04 g/t gold for 82,100 ounces using a cut-off grade of 0.4 g/t gold
was estimated.
The resource was estimated using ordinary kriging within two gently dipping geologically and
geochemically defined horizons, which extend for over 600 m east-west and 700 m north-south. The
geological and mineralogical interpretations are robust and fit well with observed regional controls.
4.5.3.
WHITE DAM ORE RESERVE
On completion of the updated Mineral Resource, a series of pit optimisations were completed for
various gold price and input assumptions. Based on the A$900/oz pit optimisation, an ultimate pit
design was completed, resulting in a Probable Ore Reserve for White Dam of 4.94 Mt at 1.07 g/t gold
for 170,400 contained ounces (0.4 g/t gold cut off). The depleted Ore Reserve as at December 2010
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was 2.2 Mt at 1.0 g/t gold for 75,000 contained ounces was completed by Doug Parbery of Australian
Mine Design and Development Pty Ltd (AMDAD) who is acting as the Competent Person for the Ore
Reserve.
4.6.
MINING, METALLURGICAL AND PROCESSING
CONSIDERATIONS
4.6.1.
MINING
The White Dam mine was officially opened in June 2010. Open cut mining, ore extraction and
stacking commenced in January 2010 (Figure 4.9). The mine is expected to produce approximately
5.1 Mt of ore at a grade of 1.0 g/t gold. At the current mining rate, mining is forecast for completion
in August 2011. Processing of ore is forecast to be finished within 12 months of the completion of
mining.
Figure 4.9
White Dam open pit, May 2010, viewed from north to south at west end of pit
4.6.2.
METALLURGY
A substantial amount of metallurgical test work has been conducted on the White Dam ore for gold
production using heap or dump leaching methods. Testing revealed that ore derived from above the
base of oxidation (between 50 m and 65 m below ground level) is not crush-size sensitive and hence
the application of dump leaching (as opposed to heap leaching where the ore is crushed and
sometimes agglomerated before leaching) is appropriate. Testing also revealed that crushing of ore
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sourced from below of the oxidation level may be required; however, the current mine design only
extracts oxide ore.
Polymetals conducted column leach tests in order to test gold recovery by heap and dump leach
methods. On average across all column tests, a 1.50 g/t gold head grade yielded 74.1% gold
recovery using 1.05 kg/t cyanide and 1.75 kg/t of lime. This was achieved using an average irrigation
ratio of 2.82 m3/t. Slumping was generally less than 5% and no percolation issues were observed.
Gold recoveries from two six tonne columns (used to test uncrushed ore) on samples collected from
shallow costeans on site gave 83.0% and 81.7% gold recovery after 108 days.
The assay by size of the leach residue indicated that the mass and gold distribution is similar,
indicating leaching through all of the size fractions.
4.6.3.
PROCESSING
Given the relatively small ore reserve, low-grade and the amenability of the ore to the process, the
White Dam deposit has been developed as a dump leach operation. Dump leaching differs from
heap leaching in that neither crushing nor agglomeration of the ore is employed; instead the ore is
stacked onto the leach pad as run-of-mine where it is irrigated with cyanide leach solution. The
resulting pregnant solution flows from the dump leach and is collected for subsequent gold recovery
using conventional carbon adsorption, desorption and electrowinning processes.
Open cut mining and ore stacking commenced in January 2010. Construction of the leach pad and
processing facilities were completed in the first quarter of 2010 and cyanide leaching of ore
commenced in March 2010. The process plant and gold recovery facilities were commissioned in
April 2010 and first gold production was achieved on 16 April 2010.
Recovery to December 2010 was 61% and 49,400 ounces of gold recovered from 2.6 Mt ore under
irrigation. Reagent consumptions are lower than the original budget (cyanide 0.2kg/t actual versus
0.5kg/t budget, lime 1.5kg/t versus 3kg/t budget). Production costs are $510/oz versus a budget of
$801/oz (October 2009 to December 2010).
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5. BOORARA
5.1.
Polymetals holds a group of 18 contiguous tenements covering an area of 3,264.39 ha (Table 5.1)
approximately 17 km to the east-south-east of the major regional centre of Kalgoorlie, Western
Australia (Figure 5.1). The mining of gold, along with other metals such as nickel, has been a major
industry in the Kalgoorlie area since the end of the 19th century, with the largest gold open pit mine
in Australia located adjacent to Kalgoorlie and referred to as 'The Super Pit'.
Table 5.1
Boorara tenements
Tenement
Holder
Grant date
Expiry date
Area [ha]
*M26/29
Polymetals (WA) Pty Ltd
31 May 1983
30 May 2025
212
*M26/161
13 May 1987
1 Dec 2029
329
*M26/318
16 Mar 1990
15 Mar 2032
697
*M26/277
22 May 1989
21 May 2031
215
P26/3420
18 Oct 2007
17 Oct 2011
10
P25/2003
23 Feb 2009
22 Feb 2013
200
P25/2030
05 Feb 2010
04 Feb 2014
146
P25/2031
08 Jan 2010
07 Jan 2014
165
P25/2061
03 Nov 2009
02 Nov 2013
123
P25/2068
08 Jan 2010
07 Jan 2014
181
P25/2069
08 Jan 2010
07 Jan 2014
149
P26/3664
28 Apr 2010
27 Apr 2014
108
P26/3699
11 June 2009
10 June 2013
93
P26/3700
11 June 2009
10 June 2013
114
P26/3701
11 June 2009
10 June 2013
120
P26/3702
12 Feb 2010
11 Feb 2014
177
P26/3704
12 Feb 2010
11 Feb 2014
186
L26/240
Pending
-
38
*subject to New Hampton Goldfield royalty of A$1.00/dry tonne processed capped at A$1.0 M
M - Mining Lease, P - Prospecting Lease
Polymetals' tenements are grouped into four areas based on geology and mineralisation:
Mining leases M26/277, M26/29 and M26/318 cover the main Boorara gold prospects,
namely the Northern Stockwork Zone, Southern Stockwork Zone, Crown Jewel, Cataract,
Chapple, and Golden Ridge North (1,124.4 ha), also referred to as the 'Boorara Mining
Centre'.
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Mining lease M26/161 (329.3 ha) covers polymetallic prospects including Gretel zinc-silver
and Condor zinc-silver. The Brindabella zinc-silver-nickel prospect and the Tramways zincsilver prospect are located on M26/29 and M26/318, respectively.
Prospecting licences including P25/2030, P25/2031, P25/2061, P25/2068, P25/2069,
P26/3420, P26/3664, P26/3699, P26/3700, P26/3701, P26/3702, P26/3704 (1572.37 ha) are
prospective for gold, silver and base metals and are located to the east of the Boorara
Mining Centre.
Prospecting licence P25/2003 covers an area of 200 ha and is located in the Balagundi area
north of Boorara. This tenement is prospective for gold.
Miscellaneous licence L26/240 is a pending application for the extraction of water, the
installation of a pipeline and associated infrastructure over parts of the Golden Ridge mine.
At Boorara the climate is hot and dry in summer and cool and dry in winter. January is the hottest
month with an average maximum temperature of 33.6°C, but temperatures above 40.0°C occur
nearly once a week when hot, dry, north to north-easterly winds predominate. Winters are cool
with July average maximum and minimum temperatures being 16.5°C and 4.8°C respectively. The
average annual rainfall is 260 mm.
The tenements are characterised by typical Eastern Goldfields physiographic features. The area is
lightly wooded with low scrubs and trees and little ground cover (Figure 5.2). The topography is
subdued with the area lying some 400 m above sea level. Streams are active only after heavy rain.
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Figure 5.1
Boorara Project - prospect locations and geology
P a g e | 44
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Figure 5.2
Rehabilitated drill site at Boorara
5.2.
5.2.1.
REGIONAL GEOLOGY
The Archaean Yilgarn block of Western Australia is one of the largest gold provinces in the world.
The major gold deposits in the Yilgarn block, including those at Kalgoorlie, are structurally controlled,
and several lie in the immediate vicinity of the Boulder Lefroy Shear Zone (BLSZ).
The north-north-west-trending BLSZ is over 200 km in length and is located within the greenstone
sequence of the Kalgoorlie terrane in the southern part of the Norseman-Wiluna belt. This belt of
metamorphosed rocks is characterised by abundant tholeiites and komatiites, overlain by felsic
volcanic and sedimentary rocks and intruded by granitic rocks (Weinberg et al., 2005).
The BLSZ and its immediate surroundings host four major gold districts, from north to south:
Paddington, Kalgoorlie, New Celebration and Kambalda-St-Ives. The Boorara Menzies Shear Zone
(BMZ) sometimes referred to as the Boorara Shear Zone (Figure 5.3), occurs parallel to and
immediately east of the BLSZ and also hosts gold mineralisation (e.g., the Boorara Mining Centre).
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Figure 5.3
Regional Geology
A - Location of the Archaean Yilgarn Craton,
B - Eastern Goldfields Province, showing major shear systems and gold deposits,
C - Geology map of part of the Eastern Goldfields Province, showing the distribution of supracrustal units, granitoids,
and major shear systems, from Morey et al (2008)
The deformation of the Norseman-Wiluna belt, including multiple shortening phases associated with
thrusting, recumbent folding and large-scale stratigraphic repetition, is related to the late Archaean
Kalgoorlie Orogeny. This orogeny was also accompanied by the intrusion of granites, as well as
major gold mineralisation.
The BMZ, which hosts the gold mineralisation at the Boorara Mining Centre, shows structural
evidence of intense shortening through the development of north-north-west-trending tight to
isoclinal folds and reverse to transpressive shear zones. This deformation event controlled the
distribution of gold mineralisation within the BMZ, which is evident as syn-shear and stockwork
veins, or conjugate planar vein arrays (Morey et al., 2007).
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5.2.2.
LOCAL GEOLOGY
Polymetals' Boorara tenements cover the Golden Ridge Fault, which is part of the BMZ. Near
Kalgoorlie, the Norseman-Wiluna Belt includes mafic to ultramafic volcanics intruded by thick
dolerite units and overlain by felsic volcanics (Keats, 1987). North-north-west to north-trending
lithological trends have been emphasised by subsequent deformation, which in part includes northnorth-west-trending shearing (e.g., the BMZ) and north-east to south-west orientated regional
shortening.
The geology of Polymetals' mining leases M26/318, M26/277 and M26/29 is characterised by shearbounded Archaean dolerites, which are in contact with intercalated ultramafic volcanics and
sedimentary units to the west and with intercalated felsic volcanics and sediments to the east
(Figure 5.1).
The eastern portion of mining lease M26/318 has a thin soil cover over bedrock that is comprised of
fine-grained siltstones, greywacke’s and graphitic sediments. West of these sub-cropping sediments,
thick laterites and soil cover often obscure the bedrock, which is interpreted to be largely composed
of felsic porphyritic volcanics (Figure 5.1).
Mining lease M26/161, which contains several base metal prospects, is located within felsic
volcanics and sedimentary units (carbonaceous shales). These north-west-trending, steeply westdipping units are bounded to the west by the BMZ and by the Kanowna Shear Zone (KSZ) to the east.
The felsic volcanic host rocks are in contact with a sequence of mafic and ultramafic volcanics to the
west.
The region has generally been subject to lower greenschist facies metamorphism, resulting in a
chlorite-sericite±carbonate metamorphic overprint on the primary mineral assemblages.
5.3.
MINERALISATION
The Boorara gold deposits are classified as Archaean shear-hosted gold (Archaean Lode) deposits.
The gold mineralisation is associated with regional shearing. Dolerites and porphyries have
preferentially intruded along the major fault zones. Mineralisation is generally confined to fractures
and alteration zones within these intrusives; however, shears within the mafic and ultramafic rocks
hosting low-grade mineralisation have also been noted between Corsair (Figure 5.1) and the Boorara
Mining Centre.
Verbeek (1987) summarised the gold mineralisation at Boorara as occurring:
near dolerite contacts associated with quartz stockwork or vein arrays
associated with quartz veins in shallow (35° to 45°) north-dipping shear zones
associated with steep (50° to 70°) west-dipping shear zones on dolerite contacts.
Additional petrographic characteristics include pervasive carbonate-sericite alteration and sulphides
occurring in vein selvedges with proximal arsenopyrite and distal pyrite. The veins are usually less
than 20 mm wide, whilst the selvedge may be one to four times the width of the vein.
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The mineralised system at the Boorara Mining Centre occurs over a strike length of 2 km including
several individual prospects (Figure 5.4). The southern areas including the Southern Stockwork Zone
have a single vein system whereas the northern areas, from Crown Jewel northwards, feature a
number of vein systems.
Figure 5.4
Prospect localities in the Boorara Mining Centre (north is to the top of the page)
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Another major gold prospect, named Chapple, is located south of the Boorara Mining Centre on
mining lease M26/318 (Figure 5.1). This prospect hosts a magnetic anomaly over which gold soil
geochemistry has been carried out with erratic results. This target is similar in morphology and
location to that associated with the Golden Ridge open pit (Figure 5.1) further to south and outside
of Polymetals' tenements.
5.4.
5.4.1.
EXPLORATION
Boorara has had a history of systematic and extensive exploration over the last three decades.
Explorers have targeted gold mineralisation in highly altered dolerite and quartz-feldspar porphyry
intrusives within the MBZ. The location of historical prospects in the broader Boorara region is
shown in Figure 5.1.
Texasgulf Australia Ltd obtained an option on the properties from 1980 to 1982. Exploration work
included dump and underground sampling in historical workings, mapping and geophysical surveys,
and both RC and diamond drilling.
Western Reefs Ltd (WR) completed numerous costeans including mapping and sampling between
1985 and 1987. WR also carried out surface and underground mapping with structural analysis, soil
sampling and ground magnetics. Additionally, rotary air blast (RAB) drilling of soil anomalies, RC and
diamond drilling was carried out. The work by WR outlined gold mineralisation at the Southern and
Northern Stockwork zones. In the subsequent years RC drilling was carried out at the Southern
Stockwork Zone (50%), Eastern Dolerite (25%), Crown Jewel (10%) and the remainder at Central
Shear, Cross Lode, Northern Stockwork Zone and Central Dolerite (Figure 5.4). A pre-feasibility study
was conducted in 1989.
Newmont Australia Ltd (later Newcrest Mining Ltd) entered into a joint venture agreement with WR
and Fimiston Mining NL (Fimiston) in 1990, with the focus on finding mineralisation away from the
known deposits, particularly on mining leases M26/318 and M26/161, and secondly to evaluate the
potential for deep mineralisation beneath the known Boorara (Mining Centre) deposits on lease
M26/29. In the following two years both RAB and RC drilling were carried out on various prospects,
including Diggers Dam, Chapple and North Golden Ridge, Eastern Dolerite, Cross Lode, Northern and
Southern Stockwork zones.
In 1993, Ramsgate Resources Ltd and General Gold Resources NL conducted an RC drilling
programme into the core areas of the Northern and Southern Stockwork zones, which improved the
understanding of the complex geometries and lithological complexities hosting the mineralisation
(Coxhell, 1997).
Fimiston managed the exploration from 1996 through to 1998 and advanced the development of the
Boorara gold resources with some infill air core (AC) and RC drilling at the Southern Stockwork Zone
as well as additional density testing. Regional wide spaced drilling also intersected gold
mineralisation at the Chapple Prospect including 4 m at 1.93 g/t gold (RC24), 2 m at 2.22 g/t gold
(RC26) and 4 m at 3.63 g/t gold (RC6).
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An auger sampling programme, restricted to the eastern boundary of the Boorara resource area and
the North Golden Ridge Prospect, was carried out in 1998. It targeted the pedogenic carbonate soil
horizon at North Golden Ridge.
In 1998, New Hampton Goldfields Ltd (New Hampton) purchased a 51% interest in M26/29,
M26/161 and M26/318 from Fimiston with an option on the remaining 49%. Between 1998 and
1999 resource calculations and pit optimisation work was completed on Crown Jewel, Cataract,
Digger Dam, and the Northern Stockwork Zone by New Hampton’s consultants. Between 2001 and
2003, RAB drilling was carried out across the mining tenements. Additionally, New Hampton carried
out mapping and structural analyses and confirmed WR’s historical data and mapping to be of high
quality. In 2004 New Hampton sold the Boorara tenements to Polymetals.
Since acquiring the Boorara mining tenements (M26/29, M26/161, M26/277 and M26/318),
Polymetals strategy has been to expand existing Mineral Resources and to generate new gold
mineralisation targets away from the existing resources. Polymetals exploration activities to date
are summarised in Table 5.2. Minor exploration work was also carried out on base metal targets on
mining leases M26/29 and M26/161 (Figure 5.1).
Table 5.2
Polymetals' exploration activities, from Kelty (2005) and Bolger (2006, 2007b, 2008, 2009 & 2010)
Year
Activities
2004
8 RC drill holes for a total of 280 m into the Southern Stockwork Zone
2005
1,705 soil geochemical samples taken on M26/277 and M26/318 defining gold anomalism
Boorara area total resource re-estimated at 1.9 Mt at 1.38 g/t gold (M26/29, M26/318)
Preliminary pit optimisations on the Boorara area resources
2006
294 auger soil geochemical samples taken M26/277 (Au), M26/161 (base metals)
Aerial photography over whole tenement area
63 RC holes were drilled for total metres of 9,682 m
2007
Drill hole collar rehabilitation audit (M26/161 100% of the area, M26/277 100% of the area,
M26/318 90% of the area)
Boorara resource review
2008
Independent Geologist Report for mining tenements M26/29, M26/277, M26/318
Rehabilitation of 140 historical drill hole collars on M26/318
2009
RC drilling for a total of 18 holes (1,774 m) on M26/29, M26/277, M26/318
Rehabilitation of historical drill hole collars on M26/29, M26/161, M26/277, and M26/318
2010
Independent Geologist Report and data review
5.4.2.
PRODUCTION
The Boorara Mining Centre includes several historical gold production sites along its several
kilometres length. The most recent mining occurred on the Golden Ridge deposit in the latter part
of the 1990s.
The historical mines at Boorara have a reported production of 30,597 ounces gold between 1896
and 1906 from 55,575 t of ore at an average recovered grade of 17.1 g/t gold.
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A further 650 ounces gold from 1,170 t of ore is reported as being produced after 1916. The Crown
Jewel Mine produced 270 ounces gold from 884 t at an average of 9.5 g/t gold during this period. In
the late 1940s to early 1950s the Zani Syndicate extracted 753 t at 6.3 g/t gold from a stockwork
zone north of the Cataract mine shaft.
The historical production was by underground methods from high-grade veins and shears at the
Cataract shaft, the East Lode shaft and the Crown Jewel shaft in the centre of the current project
area. These were developed to a maximum depth of 180 m in the vicinity of the Cataract shaft.
The related Golden Ridge mining centre, 5 km along strike to the south of Boorara and outside of the
Polymetals tenements, has a recorded production prior to 1935 of 170,580 ounces gold from
305,000 t of ore at an average grade of 17.4 g/t gold.
There is widespread occurrence of eluvial and alluvial gold over the 2 km long strike zone at Boorara
related to the principal area of past production. The area was extensively worked in the past by dryblowing and in recent times the area has been subject to a comprehensive re-working by modern
dry-blowing equipment. However, the amount of gold obtained from this source is not known.
5.5.
MINERAL RESOURCES
Polymetals’ 2006 Mineral Resource estimate covers the Northern Stockwork Zone, Crown Jewel,
Cataract – Digger Dam and the Southern Stockwork Zone, which are also referred to as the Boorara
Mining Centre. Documentation supporting the estimate has been sighted by Optiro as part of this
review and breakdowns by confidence category are given in Table 5.3.
Polymetals estimated grades by ordinary kriging using RC drill samples and minor diamond drill
samples. A mineralisation envelope was defined using a cut-off grade of 0.5 g/t gold and weathering
surfaces and lithological contacts were given precedence over grade when constructing
mineralisation solids (Bolger, 2007a). Polymetals used bulk densities of 2.0 t/m3 for the oxide and
2.6 t/m3 for the fresh material, which Optiro considers appropriate.
The Mineral Resource estimate suffers from a number of shortcomings including poor
documentation on sampling methods and QAQC procedures for drilling work carried out prior to
2006. Additionally, many older drill holes do not have down-hole surveys. For these reasons, Optiro
has restricted the highest confidence resource category to Indicated.
The 2006 resource estimate shows that Cataract and the Southern Stockwork Zone combined
contain more than 80% of the total gold metal inventory. Approximately two-thirds of the total
Mineral Resource is categorised as Indicated and Measured material, with the remaining portion
classified as Inferred.
Optiro notes that the results of drilling work carried out after 2006 have not been included in the
current Mineral Resource. In 2009, Polymetals drill-defined marginal extensions to known
mineralisation at the Southern Stockwork Zone and infilled between existing holes at Cataract as
well as at the Northern and Southern Stockwork zones in order to increase the estimation
confidence. Additionally, untested targets have been drilled between the Southern Stockwork Zone
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and Crown Jewel. Significant gold mineralisation was intercepted in all deposits, with gold
interceptions partly lying beyond the 2006 resource model. Thorough QAQC analysis has also been
carried out on assays obtained from the 2009 drilling, demonstrating that assay data quality is
reasonable. Therefore, it is Optiro's view that Polymetals' 2009 drilling has good potential to expand
the existing Mineral Resource estimate. There is also some potential for depth extensions to the
known deposits as much of the current drilling is relatively shallow.
There may also be potential to increase the estimated resource grade in future calculations as
historical data shows that there is a potential grade upside of 10% to 15% due to the presence of
coarse free gold that has not been captured by standard fire assay. This was confirmed by screen
fire assays carried out as part of Polymetals' 2009 drilling programme.
Table 5.3
Polymetals 2006 resource categories for the Northern Stockwork Zone (NSW), Cataract (CAT),
Crown Jewel (CRJ) and the Southern Stockwork Zone (SSW) using a cut-off grade of 0.5 g/t
gold, from Bolger (2007a)
Resource
Category
5.6.
Indicated
Inferred
Deposit
Tonnes
[t]
Gold grade
[g/t]
Metal
[oz]
Tonnes
[t]
Gold grade
[g/t]
Metal
[oz]
NSW
96,000
1.46
4,500
1000
3.87
100
CAT
399,000
1.57
20,200
413,000
1.53
20,300
CRJ
65,000
1.38
2,900
116,000
1.70
6,300
SSW
730,000
1.14
26,800
86,000
1.28
3,500
Total
1,290,000
1.31
54,400
616,000
1.53
30,200
EXPLORATION POTENTIAL
The Boorara Project is at a moderately advanced stage of exploration. A corridor of mineralisation
has been delineated and a range of styles of mineralisation within this corridor have been identified.
The geometry of the mineralised structures and the subsequent implications for drillhole orientation
and spacing present the main challenges to project development.
Exploration targets in the southern portion of the project area, between the Southern Stockwork
Zone and the Golden Ridge Mine to the south, have been identified by past workers but are yet to
be fully tested. The extension of the mineralisation to the north is also untested. Some depth
potential may exist, but will be restricted to isolated higher grade veins.
Anomalies at Chapple and Golden Ridge North along the main fault zone to the south of the
Southern Stockwork Zone are still at an early stage of exploration and require further work.
Polymetals also holds a number of prospecting licences in the Boorara area which host similar
stratigraphy to the Boorara Mining Centre, including some regional structures. While exploration on
these tenements is at an early stage, Optiro considers them to be prospective for gold and silver
mineralisation.
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6. EXPLORATION STRATEGY AND BUDGET
Polymetals has proposed a budget that will fund work required for exploration and resource
development for its three key assets in New South Wales, South Australia and Western Australia
(Table 6.1) using the following generic phases:
1. Discovery using geochemical and geophysical surveys followed by RAB drilling
2. Scout drilling following a discovery to determine if potentially economic deposits exist
3. Delineation drilling designed to delineate the extent of mineralisation if the deposit appears
favourable
4. Definition drilling designed to allow resource estimation that will support feasibility studies
5. Mine production
The funds would be spent over a two year period following Polymetals capital raising and would, at
the end of this period, enable Polymetals to advance towards recommencing gold production at
Canbelego and to extend the Mineral Resource and Ore Reserves at Drew Hill and the Mineral
Resource at Boorara.
The detailed budget proposals for each of the projects are presented in the following sections of this
report. Polymetals’ strategy places the greatest emphasis on the development and exploration of
Canbelego and the least emphasis on Boorara. In Optiro’s opinion the planned prioritisation and
exploration programmes have been designed to explore the three project areas in a prudent and
efficient manner. Optiro notes that the planned expenditure significantly exceeds the anticipated
minimum annual statutory expenditure commitment on the tenements.
Table 6.1
Polymetals proposed exploration and development budget for its key assets in Australia
Project
Activity
Mount Boppy Extension
exploration
Canbelego
Regional exploration
Drew Hill
Exploration
Boorara
Southern Stockwork
resource development
Total
Cost [A$M]
Year 1
1.350
Year 2
2.466
Year 1
1.416
Year 2
0.651
Year 1 near mine
0.466
Year 2 regional
Funded from mining cash flow
Year 1
0.371
6.720
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6.1.
CANBELEGO
Polymetals’ strategy at Canbelego is to increase the existing Mineral Resources to allow gold
production to recommence. Polymetals considers that 500,000 oz of gold resources including
200,000 oz of gold reserves are required for a viable outcome and development to be considered.
Two separate programmes of work are proposed to support this target; one focussing on extensions
to the existing Mount Boppy open pit; the other targeting opportunities within the broader
Canbelego area.
6.1.1.
MT BOPPY EXTENSION PROGRAMME
The Mount Boppy mine extension programme comprises two stages. The first stage consists of drill
testing for faulted offsets of the mineralised zone to the south of the pit and for structural
repetitions below and along strike from the pit. An anticipated 5,000 m of RC and diamond drilling is
planned to complete fourteen 350 m long holes at an approximate cost of $1,330,000 during the
twelve months after listing the company. A small additional allowance of $20,000 is included to
undertake petrological and other drill core based analysis. A scoping study designed to evaluate
cutback options for the Mount Boppy pit will be completed incorporating the stage one drilling
results.
A successful outcome from the scoping study will predicate the next stage of work which will be
completed in the second year after listing. This work involves a definition drilling programme
comprising around seventy-five 220 m long reverse circulation holes to support a Mineral Resource
estimate of an appropriate standard to undertake a feasibility study. The amount of drilling required
cannot be accurately predicted until after the first stage is complete, however, it is estimated that
around 16,500 m of drilling supporting grade sampling, geotechnical logging and metallurgical test
work will be required at an approximate cost of $2,466,000.
6.1.2.
CANBELEGO EXPLORATION PROGRAMME
The Canbelego exploration programme is aimed at drill testing for Cobar style precious metal
mineralisation in the vicinity of the Mount Boppy mine (e.g. Birthday, Reid Rankin’s and Hardwick’s
deposits) and further afield at the Pipeline Ridge deposit. Drilling will also be used to evaluate
prioritised precious and base metal prospects within the exploration tenement.
A combination of aeromagnetic and gravity surveys, scout drilling and delineation drilling is planned
in the first year after listing. Scout drilling using RC techniques will be conducted at Nova, Pipeline
Ridge, Boppy South, Reid Rankin’s, Wealth of Nations and any new prospects that may be identified.
Typically, five to ten 100 m to 150 m long holes are planned for each location to test for
mineralisation. Delineation drilling using diamond drillhole techniques is planned at Hardwick’s,
Birthday and Boppy South. Two to four 100 m to 200 m long holes are planned for each location to
test the mineralisation. The expenditure in the first year is anticipated to be $1,416,000.
Resource definition drilling is planned for the second year after listing. While this programme will be
dependent on the first year’s results, it is anticipated that definition drilling will be conducted at
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Hardwick’s and Birthday using RC methods. Around twenty 100 m long holes will be completed at
each location. The plan for the second year also includes undertaking resource estimation and pit
optimisation tasks for the Boppy South deposit. The expenditure planned to complete this
programme of work is $651,000.
6.2.
DREW HILL
Polymetals’ strategy at Drew Hill is to continue to define Mineral Resources that will support Ore
Reserves which will maximise the life of the White Dam Project. The exploration work required to
achieve this outcome is divided into two stages.
Recent past exploration efforts have focussed on the Vertigo deposit and this has led to the recent
delivery of a Mineral Resource estimate that is suitable to support pit optimisation and other project
feasibility work. Recent exploration drilling of other prospects has met with success at Ambush and
White Dam North but results were discouraging at White Dam South.
The White Dam Production joint venture has a budget of $1,864,000 for the 2011 calendar year. The
joint venture arrangement means that Polymetals share of this cost is $466,000. This expenditure is
based notionally on the concept of 28,400 m of RC drilling spread over four campaigns.
Exploration will continue in the following year and will pursue gold, iron ore and uranium
opportunities at Drew Hill. Polymetals anticipates funding this expenditure from the cashflow
achieved by production at White Dam.
6.3.
BOORARA
Polymetals’ strategy at Boorara is to expand existing Mineral Resources and to undertake a study to
determine project economics.
A drilling program of 18 RC drillholes completed in 2009 was designed to test the gap between the
Southern Stockwork and Crown Jewel deposits as well as other goals. Some drilling success was
achieved in the Southern Stockwork and Polymetals considers the strike extension of this deposit to
offer the best opportunity to increase the size of the Mineral Resource at depths down to 180 m
below surface.
Polymetals intend to complete seven diamond drillholes for a total metreage of around 1,200 m at a
cost of $371,000. These holes will be targeted at extensions to, and some infill of, known
mineralisation. This work will be undertaken in the 12 months following listing.
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7. REFERENCES
Allen, R.M. (2003.): Structural Controls of the Mount Boppy Gold Mineralisation. CSA Australia Pty
Ltd, August 2003, 26p.
Bolger, C. (2006): Combined Annual Report Nimbus - Boorara Project, Reporting Group C89/2004 Year ending February 26, 2006. Polymetals (WA) Pty Ltd, 34p.
Bolger, C. (2007a): Boorara Mining Centre M26/29, M26/318 - Resource Review, November 2007.
Polymetals Group Pty Ltd, unpublished company report, 122p.
Bolger, C. (2007b): Combined Annual Report Nimbus - Boorara Project, Reporting Group C89/2004 Year ending February 26, 2007. Polymetals (WA) Pty Ltd, 33p.
Bolger, C. (2008): Mount Boppy Gold Mine - Summary Details Resource Estimate, September November 2008. Polymetals Group Pty Ltd.
Bolger, C. (2009b): White Dam Gold Deposit, September 2009 - Resource Estimate. Polymetals
Group Pty Ltd (Unpublished company report), 35p.
Bolger C. (2009c): Memorandum - White Dam Mineral Resources. Polymetals Group Pty Ltd
(Unpublished company report), 53p.
Bolger, C. (2010): Boorara RC Drilling - Screen Fire Assays Report, October 2009. Polymetals Group
Pty Ltd, unpublished company report, 16p.
Conor, C. H. H. (2000): Definition of major sedimentary and igneous units of the Olary Domain,
Curnamona Province, South Australia. MESA Journal, 19, 5156.
Conor, C. H. H., Ashley, P. M., Bierlein, F. B., Cook, N. D. J., Crooks, A. F., Lawie, D. C., Plimer, I. R.,
Preiss, V. P., Robertson, R. S. and Skirrow, R. G. (2006): Geology of the Olary Domain, Curnamona
Province, South Australia. Report Book, 2006/13, 95p.
Cordon, E.L. (1998): An investigation into the mineralisation of the White Dam prospect, Olary
Block, South Australia. University of Adelaide, BSc (Hons) thesis (unpublished).
Cox, D. (2006): Boorara, Cataract, Pit Optimisation - Preliminary Investigation, August 2005. Crystal
Sun Consulting, unpublished company report, 7p.
Cox, D. (2006): Boorara, Southern Stockwork, Pit Optimisation - Preliminary Investigation, August
2005. Crystal Sun Consulting, unpublished company report, 7p.
Coxhell, S. (1997): Reappraisal and Data Compilation and Resource Estimation of the Boorara Mining
Centre. Unpublished Company Report, Fimiston Mining N.L.
Exco (2008): Drew Hill Project. Rehabilitation Status Report. July 2008, by Exco Resources (SA) Pty
Ltd.
Exco (2011a): White Dam Gold Project – Vertigo Resource Upgrade.
announcement to ASX dated 14 January 2011.
Exco Resources Ltd,
Exco (2011b): White Dam Production and Resource Update. Exco Resources Ltd, announcement to
ASX dated 11 March 2011.
Fuller, P. (2006): Mount Boppy Technical Review. Coffey Mining for Polymetals Mining Services.
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Glen, R.A. (1987): Copper and gold rich deposits in deformed turbidites at Cobar, Australia: their
structural control and hydrothermal origin. Economic Geology 82, 124 - 140.
GCR (2002): Golden Cross Resource Ltd. Quarterly report to 30 June 2002
Harvey, K. (2005a): Mount Boppy Gold Mine Geological Report, May 2005. Polymetals Mining
Services Pty Ltd.
Harvey, K. (2005b): Mount Boppy Gold Mine Resource Modelling, September 2005. Polymetals
Mining Services Pty Ltd.
Jones, D. (2010): Exploration Recommendation for EL3842 for Polymetals Group Pty Ltd. Prepared by
Vidoro Pty Ltd for Polymetals Group Pty Ltd, 30p.
Keats, W. (1987): Regional Geology of the Kalgoorlie-Boulder gold mining district. Western Australia
Geological Survey Report, 21, 44p.
Kelty, B. (2005): Combined Annual Report, Nimbus Silver Mine - Year ending February 26, 2005.
Polymetals (WA) Pty Ltd, 10p.
Lau, I.C. (2004): Regolith Landform and Mineralogical Mapping of the White Dam Prospect, Eastern
Olary Domain, South Australia, Using Integrated Remote Sensing and Spectral Techniques.
University of Adelaide PhD Thesis (published by CRCLEME), 457p.
Lawrie, K.C. and Hinman, M.C. (1998): Cobar-style polymetallic Au-Cu-Ag-Pb-Zn deposits. AGSO
Journal of Australian Geology and Geophysics, 17, 4, 169 - 187.
Lawry, A. (2010): Memorandum - Mt Boppy Metallurgical Recovery. Polymetals Group Pty Ltd
(unpublished company report), 3p.
Leyh, W. and Conor, C. H. H. (2000): Stratigraphically Controlled Metallogenic Zonation Associated
with the Regional REDOX Boundary of the Willyama Supergroup. MESA Journal, 16, 4143.
McQueen, K. (2005): The Mount Boppy Gold Mine, NSW: A Leader in its Day and More to Come.
Journal of Australasian Mining History, Vol. 3, September 2005.
Morey, A.A., Weinberg, R. and Bierlein, F. (2007): The structural controls of gold mineralisation
within the Bardoc Tectonic Zone, Eastern Goldfields Province, Western Australia: implications for
gold endowment in shear systems. Mineralium Deposita, 42, 583 - 600.
Morey, A.A., Tomkins, A.G., Bierlein, F.P., Weinberg, R.F. and Davidson, G. (2008): Bimodal
Distribution of Gold in Pyrite and Arsenopyrite: Examples from the Archaean Boorara and Bardoc
shear Systems, Yilgarn Craton, Western Australia. Economic Geology, 103, 599 - 614.
Page, R.W., Conor, C.H.H., Stevens, B.P.J., Gibson, G.M., Preiss, W.V. and Southgate, P.N. (2005):
Correlation of Olary and Broken Hill Domains, Curnamona Province: Possible Relationship to Mount
Isa and Other North Australian Pb-Zn-Ag-Bearing Successions. Economic Geology, 100, 663 - 676.
Schifano, J. and Burrell, P. (2009): Exploration License 5842 Canbelego and EL6440 Buppe. Final Joint
Report, January 2009. Golden Cross Operations Pty Ltd., 41p.
Stegman, C.L. (2001): Cobar deposits: Still defining Classification. SEG Newsletter 44, 15 - 25.
Verbeek, P. (1987): Annual Report Boorara Project M26/29, P26/161-3, P26/850-8 Period ending
May 1987. Item 14306 Report A21066.
Weinberg, R.F., Van der Borgh, P., Bateman, R.J. and Groves, D.I. (2005): Kinematic history of the
Boulder-Lefroy Shear Zone System and Controls on Associated Gold Mineralization, Yilgarn Craton,
Western Australia. Economic Geology, 100, 1407 - 1426.
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8. GLOSSARY OF TECHNICAL TERMS
Term
Abbreviations
aircore drilling
albite
albitised
alkali feldspar
alluvial gold
alteration
Archaean
arenitic
arsenopyrite
auger soil sampling
basement
base metals
basin (sedimentary)
basin inversion
bedrock
biotite
block model
breccia
Explanation
% - percentage
AC – aircore drilling
CIP - carbon in pulp
DD – diamond drilling
EM – electromagnetic
IOCG – iron oxide, copper, gold (deposits)
JV – joint venture
g/t – grams per tonne
km – kilometre
2
km – square kilometres
kt – kilotonnes
m – metre
M – million
3
m – cubic metres
Ma – million years
mm – millimetres
Mt – million tonnes
Mtpa – million tonnes per annum
oz – ounce
QAQC – quality assurance, quality control
RAB – rotary air blast drilling
RC – reverse circulation drilling
t – tonnes
This drilling method uses blades to bore a hole into unconsolidated ground. The rods are
hollow and contain an inner tube which sits inside the hollow outer rod barrel. The drill
cuttings are removed by injection of compressed air into the hole and brought back to the
surface up the inner tube.
An alkali feldspar mineral. It is the sodium end member of the plagioclase solid solution series.
Formation of albite (sodium feldspar) in pre-existing rock.
Feldspar rich in sodium or potassium, e.g., albite. Feldspars are a group of rock-forming silicate
minerals, which make up as much as 60% of the Earth's crust.
An accumulation of alluvium (sediment), sometimes containing gold in the bed or former bed of
a river.
A change in mineralogical composition of a rock through reactions with hydrothermal fluids,
temperature or pressure changes.
Era of the geological time scale containing rocks greater than 2500 million years old.
Pertaining to sedimentary rocks composed of sand-sized particles irrespective of composition.
Most common arsenic mineral and principal ore of arsenic.
A sampling technique that uses a helical screw, which is driven into the ground with rotation.
The soil is lifted up the borehole by the blade of the screw.
The surface beneath which sedimentary rocks are not found; the igneous, metamorphic, or
highly deformed rock underlying sedimentary rocks.
Non-ferrous (other than iron and alloys) metals excluding precious metals. These include
copper, lead, nickel and zinc.
Refers to any geographical feature exhibiting subsidence (downward shift) and consequent
infilling by sedimentation.
In structural geology basin inversion relates to the relative uplift of a sedimentary basin as a
result of crustal shortening.
The solid rock lying beneath superficial material such as gravel or soil.
Also referred to as 'dark mica'. A common sheet silicate within the mica group, with the
approximate chemical formula K(Mg, Fe)3AlSi3O10(F, OH)2.
A model comprised of rectangular blocks, each with attributes such as grades, rock types, codes
that represents a given mineral deposit.
A detrital sedimentary rock composed of poorly sorted fragments which are all angular to sub-
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Term
Brecciated/brecciation
bulk density
calc-albitite
calc-silicate
carbonaceous
carbonate
carbon in pulp (CIP)
certified standard
chalcocite
chlorite
classification
clastic
coarse free gold
conglomerate
conjugate veins
core
craton
cut-off grade
cyanidation
dacite
deformation
Delamerian
Devonian
diamond drilling
dip
dolerite
dolomite
drillhole data
dykes
early Proterozoic
electromagnetic (EM)
geophysical surveys
eluvial
epithermal gold
epigenetic
(mineralisation)
exploration licence
fault
fault breccia
Explanation
angular in shape, and have a particle size of greater than 2 mm.
Converted into or resembling a breccia.
A property of particulate materials. It is the mass of many particles of the material divided by
the volume they occupy. The volume includes the space between particles as well as the space
inside the pores of individual particles.
Igneous rock composed almost entirely of albite with minor calcium carbonate.
A type of metamorphic rock in which calcium and silicon are the dominant constituents, and
which is derived from quartz-bearing dolomites and limestones.
A rock or sediment that is rich in carbon or containing organic matter.
A class of sedimentary rocks composed primarily of carbonate minerals. The two major types
are limestone and dolomite.
An extraction technique for recovery of gold which has been liberated into a cyanide solution as
part of the gold cyanidation process.
An analytical reference material of known true value used for quality control of laboratory
assays.
A copper sulphide mineral
A group of mostly green minerals of varying composition often found as alteration products of
ferromagnesian minerals.
A system for reporting Mineral Resources and Ore Reserves according to a number of accepted
Codes.
Composed of clasts or broken pieces of older rocks
Gold occurring as large grains or 'nuggets'.
A detrital sedimentary rock composed of rounded to sub-rounded shaped fragments, which
have a particle size of greater than 2mm.
A set of veins that develops synchronously.
See diamond drilling.
A stable area of continental crust that has not undergone much plate tectonic or orogenic
activity for a long period.
The grade that differentiates between mineralised material that is economic to mine and
material that is not.
A metallurgical technique for extracting gold by converting the gold to a water soluble complex.
It is the most commonly used process for gold extraction. One common process for the
recovery of the solubilised gold from the solution is carbon in leach.
An igneous, volcanic rock. Its principal minerals are feldspar and quartz, which occur in a
microcrystalline groundmass.
Term used to describe changes in rocks after their formation, usually caused by tectonic forces.
A structural event that occurred 480 to 500 million years ago
Time interval of the Palaeozoic Era (410 to 360 Ma).
Drilling method which produces a cylindrical core of rock by drilling with a diamond tipped bit.
Geological measurement – the angle at which bedding or a structure is inclined from the
horizontal.
Basaltic rocks which are comparatively coarse grained.
A carbonate rock consisting of calcium magnesium carbonate.
Data collected from the drilling, sampling and assaying of drillholes.
A tabular igneous intrusive rock that cuts across the bedding or foliation of the country rock.
The oldest period of the Proterozoic Era of the geological time scale within the Precambrian
eon containing rocks of approximately 2500 million years old.
Survey over an area involving the measurement of alternating magnetic fields associated with
currents artificially or naturally maintained in the ground.
An incoherent ore deposit resulting from decomposition or disintegration of rock in place.
Epithermal gold deposits form in hydrothermal systems related to volcanic activity exhaust
shaft Ventilation shaft for removal of exhaust from underground workings.
Mineralisation introduced into pre-existing rocks.
Rights to explore for minerals in an area, granted by a government to an individual/company.
A fracture in rock along which displacement has occurred.
Breccia produced by movement along a fault.
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Term
feldspar
felsic
fire assay
fold (folding)
foliation
fossiliferous
fracture
garnet
geological domains
geophysical survey
geotechnical strength
testing
gneiss
graben
grade control
granite
granitic (intrusion)
granitoid
graphite
graphitic
gravity survey
greenschist facies
greenstone belt
greenstones
greywacke
high resolution ground
survey
hydrothermal
in situ
Indicated Mineral
Resource
induced polarisation (IP)
geophysical survey
Inferred Mineral
Resource
Explanation
An important group of rock-forming minerals which make approximately 60% of the Earth's
crust. Feldspars crystallize from magma in both intrusive and extrusive rocks.
Silicate minerals, magmas, and rocks which are enriched in the lighter elements such as silica,
oxygen, aluminium, sodium, and potassium.
A mineral assay testing for precious metals. It involves smelting the sample which has been
mixed with lead oxide.
A flexure in rocks.
Parallel orientation of platy minerals or mineral banding in rocks.
(Rocks) containing fossils (prehistoric remains).
A break in a rock due to mechanical failure by stress.
A group of silicate minerals, common in metamorphic rocks (gneisses and schists) and often an
accessory mineral in igneous rocks. The basic chemical formula is A3B2(SiO4)3, where A = Ca,
2+
2+
3+
3+
3+
2+
Mg, Fe , or Mn , and B may be Al, Fe , Mn , V or Cr . The following names are given to
the end members of the group: almandine (Fe, Al), andradite (Ca, Fe), grossular (Ca, Al), pyrope
(Mg, Al), spessartine (Mn, Al), uvarovite (Ca, Cr), goldmanite (Ca, V).
Spatial domains created to represent areas with similar geological characteristics.
A survey that measures the physical properties of rock formations, commonly magnetism,
specific gravity, electrical conductivity and radioactivity.
Analysis of the factors affecting the stability of a rock mass.
A banded or foliated metamorphic rock, usually of the same composition as granite
A crustal block that has been depressed relative to the blocks on either sides. The bordering
faults (on the long side of the graben) are usually of near-parallel strike and steeply dipping. In
its initial surface form, it is typically a linear structural depression.
The process of collecting geological, sample and assay information for the delineation of
mineable ore boundaries; the minimization of dilution and ore loss, and the reconciliation of
the predicted grade and tonnage to the grade and tonnage mined and milled.
A coarse grained intrusive felsic igneous rock.
Granite rock which has been emplaced into the earth’s crust.
A common and widely-occurring type of intrusive, felsic, igneous rock.
A mineralised form of carbon.
Pertaining to rocks containing graphite. Graphite is carbon derived from carbonaceous material
of organic origin. Common in metamorphic rocks such as gneisses, marbles, and schists.
Geophysical method to explore mineral deposits measuring variations in the Earth's
gravitational field.
Assemblage of minerals formed during regional metamorphism.
Zones of variably metamorphosed mafic to ultramafic volcanic sequences with associated
sedimentary rocks that occur within Archaean and Proterozoic cratons between granite and
gneiss bodies.
Any green, weakly metamorphosed igneous rock whose colour is due to chlorite, actinolite, or
epidote.
A variety of sandstone generally characterized by its hardness, dark color, and poorly-sorted,
angular grains of quartz, feldspar, and small rock fragments set in a compact, clay-fine matrix.
A ground geophysical survey carried out with a high sampling density – usually magnetic, but
may be electrical.
The actions of hot water or the products produced by the action of hot water.
Material found in its original position of formation. Latin for ‘in place’.
‘An ‘Indicated Mineral Resource’ is that part of a Mineral Resource for which tonnage,
densities, shape, physical characteristics, grade and mineral content can be estimated with a
reasonable level of confidence. It is based on exploration, sampling and testing information
gathered through appropriate techniques from locations such as outcrops, trenches, pits,
workings and drill holes. The locations are too widely or inappropriately spaced to confirm
geological and/or grade continuity but are spaced closely enough for continuity to be assumed.’
(JORC 2004)
Survey over an area involving the application of an electric or magnetic field and measurement
of the decay of voltage in the earth when the field is switched off.
‘An ‘Inferred Mineral Resource’ is that part of a Mineral Resource for which tonnage, grade and
mineral content can be estimated with a low level of confidence. It is inferred from geological
P a g e | 60
Mining Limited
Term
intercept
intrabasinal
intrusion
iron oxides
isoclinal
JORC Code
komatiite
kriging
kyanite
lapilli tuff
laterite
leucocratic
lithology
lode
mafic
Mafic/ultramafic dykes
magnetic anomaly (high /
low)
magnetic geophysical
survey
Measured Mineral
Resource
Mesoproterozoic
metallurgy
metamorphic
metamorphism
metapelite
metasedimentary
mica
migmatitic
Mineral Resource
Explanation
evidence and assumed but not verified geological and/or grade continuity. It is based on
information gathered through appropriate techniques from locations such as outcrops,
trenches, pits, workings and drill holes which may be limited or of uncertain quality and
reliability.’ (JORC 2004)
Mineralised intersection in a borehole.
Within a part of the earhs surface consisting of rock strata that slope down to a common centre
The emplacement of magma into pre-existing rock.
Minerals composed of iron and oxygen, e.g., hematite, magnetite.
A fold in which the limbs are parallel or near-parallel.
The JORC Code provides minimum standards for public reporting to ensure that investors and
their advisers have all the information they would reasonably require for forming a reliable
opinion on the results and estimates being reported. The current version is dated 2004.
Ultramafic mantle-derived volcanic rocks. They have low SiO2, low K2O, low Al2O3, and high to
extremely high MgO. Komatiites occur with other ultramafic and high-magnesian mafic volcanic
rocks in Archaean greenstone belts.
A geostatistical estimation method using a distance weighting technique which is based upon
the relative spatial continuity of the samples.
See sillimanite.
Pyroclastic rock composed of consolidated volcanic ejecta measuring 2 to 64 mm in diameter.
Pyroclastic refers to materials formed by volcanic explosion or aerial ejection from a volcanic
vent.
A soil residue composed of secondary oxides of iron, aluminium or both.
Describes light coloured igneous rocks, containing between 0% and 35% of dark minerals.
The study and description of rocks, including their mineral composition and texture.
Ore zone.
Silicate minerals, magmas, and volcanic and intrusive igneous rocks that have relatively high
concentrations of the heavier and darker minerals.
Tabular intrusive igneous rocks comprised of high proportions of magnesium and iron rich
minerals
Magnetic signatures different from the background, made up of a high and a low (dipole)
compared to the average field.
Survey over an area involving measurements of magnetic intensity of rocks in response to the
earth’s magnetic field. Different rock compositions show varying degrees of magnetic intensity,
which can be used to infer changes in geology.
‘A ‘Measured Mineral Resource’ is that part of a Mineral Resource for which tonnage, densities,
shape, physical characteristics, grade and mineral content can be estimated with a high level of
confidence. It is based on detailed and reliable exploration, sampling and testing information
gathered through appropriate techniques from locations such as outcrops, trenches, pits,
workings and drill holes. The locations are spaced closely enough to confirm geological and
grade continuity.’ JORC 2004.
A geological era that occurred between 1,600 Ma and 1,000 Ma ago.
Study of the physical properties of metals as affected by composition, mechanical working and
heat treatment.
The process of metamorphism or its results.
Alteration of the minerals, texture and composition of a rock caused by exposure to heat,
pressure and chemical actions.
Metamorphic mudstone.
A sediment or sedimentary rock that shows evidence of having being subjected to
metamorphism.
A group of sheet silicate minerals that occurs widely in igneous, metamorphic and sedimentary
rocks.
Banded or veined appearance of rocks (with granitic composition), formed by partial melting
under very high temperatures and pressures.
‘A ‘Mineral Resource’ is a concentration or occurrence of material of intrinsic economic interest
in or on the Earth’s crust in such form, quality and quantity that there are reasonable prospects
for eventual economic extraction. The location, quantity, grade, geological characteristics and
continuity of a Mineral Resource are known, estimated or interpreted from specific geological
evidence and knowledge. Mineral Resources are sub-divided, in order of increasing geological
P a g e | 61
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Term
mineralisation
mineralisation solid
mineralogical
mining lease
muscovite (white mica)
Olarian
ordinary kriging
Ordovician
ore
Ore Reserve
orebody
orogeny
oxidation, oxidised
Palaeozoic
pedogenic
pegmatite
pelitic
petrology
phyllite
pit optimisation
plunge
polymetallic
porphyritic
porphyry
post-orogenic
Precambrian
pre-feasibility study
Probable Ore Reserve
Explanation
confidence, into Inferred, Indicated and Measured categories.’ JORC 2004.
The process by which a mineral or minerals are introduced into a rock, resulting in a valuable
deposit.
See wireframe.
The study of minerals: formation, occurrence, properties, composition and classification.
A right to operate a mine.
A mineral of the mica group, which may be white or yellow, or sometimes dark-brown. It is one
of the most common minerals in rocks, K2Al4[Si6Al2O20](OH, F)4.
A period of large scale structural deformation that occurred around 1.58 billion years ago (see
Orogeny)
A geostatistical estimation method which relies upon a model of spatial continuity as defined in
a variogram.
A geological period of time extending from 505 to 440 Ma.
Mineralised material which is economically mineable at the time of extraction and processing.
‘An ‘Ore Reserve’ is the economically mineable part of a Measured and/or Indicated Mineral
Resource. It includes diluting materials and allowances for losses, which may occur when the
material is mined. Appropriate assessments and studies have been carried out, and include
consideration of and modification by realistically assumed mining, metallurgical, economic,
marketing, legal, environmental, social and governmental factors. These assessments
demonstrate at the time of reporting that extraction could reasonably be justified. Ore
Reserves are sub-divided in order of increasing confidence into Probable Ore Reserves and
Proved Ore Reserves.’ (JORC, 2004)
Usually refers to the deposit as a whole.
The process of mountain building, and may be studied as a tectonic structural event, as a
geographical event and a chronological event, in that orogenic events cause distinctive
structural phenomena and related tectonic activity, affect certain regions of rocks and crust and
happen within a time frame.
The addition of oxygen to the metal ion, generally as a result of weathering.
The geological era extending from about 590 Ma to 250 Ma. The Lower Palaeozoic includes the
Cambrian, Ordovician, and Silurian periods. The Upper Palaeozoic includes the Devonian,
Carboniferous and Permian periods; it was preceded by the Precambrian and followed by the
Mesozoic.
Pertaining to soil formation.
A very coarse-grained igneous rock (with grain sizes larger than 1 to 2 cm), typically found
around the margins of large intrusions. Pegmatite bodies may be veins or lenticular or podlike
in shape.
Pertaining to or derived from pelite (mudstone).
The branch of geology that studies rocks: their origin and formation and mineral composition
and classification
A type of foliated metamorphic rock primarily composed of quartz, sericite mica, and chlorite.
A mathematical process whereby an open cut volume is optimised according to certain financial
criteria.
The inclination of a fold axis or other linear structure measured in the vertical plane.
Co-existence of 2 or more metals within an ore deposit.
Describes any igneous rock containing large crystals in a ground mass of smaller crystals or
glass.
A variety of igneous rock consisting of large-grained crystals, such as feldspar or quartz,
dispersed in a fine-grained feldspathic matrix or groundmass.
Subsequent to an orogeny (see orogeny).
Rocks older than the Cambrian age.
Preliminary assessment of a project to determine mining and processing methods, capital costs,
logistics etc.
A ‘Probable Ore Reserve’ is the economically mineable part of an Indicated, and in some
circumstances, a Measured Mineral Resource. It includes diluting materials and allowances for
losses which may occur when the material is mined. Appropriate assessments and studies have
been carried out, and include consideration of and modification by realistically assumed
mining, metallurgical, economic, marketing, legal, environmental, social and governmental
factors These assessments demonstrate at the time of reporting that extraction could
P a g e | 62
Mining Limited
Term
Proterozoic
Proved Ore Reserve
pyrite
QAQC
quartz
quartzo-feldspathic
radiometrics
range
redox boundary
reconciliation
recovery (metallurgy)
regolith
reverse circulation
drilling (RC)
reverse shear zone
rhyolite
rift
rotary air blast (RAB)
drilling
sandstone
schist
screen fire assay
search pass
sedimentary
sediments
selvedge
sericite alteration
sericitic
shale
shear
silica
silicified
sillimanite
siltstone
Silurian
soil auger sampling
soil geochemical survey
Explanation
reasonably be justified. (JORC, 2004)
Era of the geological time scale within the Precambrian eon containing rocks of approximately
1000 – 2500 million years old.
A ‘Proved Ore Reserve’ is the economically mineable part of a Measured Mineral Resource. It
includes diluting materials and allowances for losses which may occur when the material is
mined. Appropriate assessments and studies have been carried out, and include consideration
of and modification by realistically assumed mining, metallurgical, economic, marketing, legal,
environmental, social and governmental factors. These assessments demonstrate at the time of
reporting that extraction could reasonably be justified. (JORC, 2004)
Iron disulphide, (FeS2).
Quality assurance and quality control.
Crystalline silica (SiO2).
Comprised of quartz and feldspar minerals
A survey pertaining to the measurement of geologic time by the study of parent and/or
daughter isotopic abundances and known disintegration rates of the radioactive parent
isotopes.
The distance at which the model reaches its maximum value.
The interface of reduced and oxidised rock units.
Measured assessment of the forecast and review of its correctness.
The percentage of metal that can be recovered given the limitations of the processing
equipment.
Unconsolidated rock material resting on bedrock, found at and near the surface of the Earth.
Residual regolith is formed by the mechanical and chemical weathering of bedrock; transported
regolith is moved and deposited by processes acting at or near the Earth's surface.
Drilling method that uses compressed air and a hammer bit to produce rock chips.
See thrusting.
Rhyolite is an igneous, volcanic (extrusive) rock, of felsic (silica-rich) composition
A place where the Earth's crust and lithosphere are being pulled apart.
A cheap and quick drilling method using a rotating bit together with air pressure to produce
rock chips for sampling. It is used at the exploration stage of project evaluation.
A sedimentary rock of sand size particles.
A group of medium-grade metamorphic rocks, chiefly notable for the preponderance of
lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others.
Development on tradition fire assay analysis (see fire assay). Screen fire assay takes a larger
sample than traditionally used for fire assay and separates the coarse gold (see coarse free
gold) by screening.
A process used in grade estimation to find samples from a given point.
Refers to rock forming processes where material is derived from pre-existing rocks by
weathering and erosion.
Loose, unconsolidated deposit of debris that accumulates on the Earth’s surface.
A zone of altered rock at the edge of a rock mass
Fine grained mica formed by the decay of feldspar.
Contains sericite alteration
A detrital sedimentary rock composed of clay minerals with a well marked bedding plane
usually due to the alignment of the clay minerals.
Fault.
Most commonly quartz (SiO2).
The introduction of, or replacement by silica, generally resulting in the formation of finegrained quartz.
An alumino-silicate mineral with the chemical formula Al2SiO5. It is one of three aluminosilicate polymorphs, the other two being andalusite and kyanite. Polymorphism is the ability of
a mineral to exist in more than one crystal structure.
A detrital sedimentary rock composed of clay minerals similar to mudstone but with mostly silt1
1
grade material ( /16 - /256) mm.
A division of the Palaeozoic era extending from 440 to 410 Ma.
See auger soil sampling
Widely used method of exploration for identifying of geochemical anomalies.
P a g e | 63
Mining Limited
Term
(or sampling)
standard
staurolite
stockwork
stope backfill
stratabound
stratigraphic
stratigraphy
strike
sulphide
supracrustal
supergene
suture
syn-tectonic
tectono-stratigraphic
terrane
tholeiite
thrusting
top-cut
transpressive shear zone
tuffs
ultramafic
vein
volcanoclastic-siliciclastic
weathering
wireframe
Explanation
See certified standards.
A metamorphic silicate mineral typical of medium-temperature conditions associated with
garnet and kyanite; it is used as a means of defining the metamorphic type and grade of the
host rock.
A network of veins.
Material (commonly tailings or a mixture of tailings and cement) backfilling open spaces (mined
areas) of an underground mine.
A mineral deposit confined to a single stratigraphic unit
Refers to a body of strata recognisable as a unit that may be used for mapping, description, or
correlation.
The study of stratified rocks, their timing, characteristics and correlations in different locations.
Geological measurement – the direction of bearing of bedding or structure in the horizontal
plane.
Minerals consisting of a chemical combination of sulphur with a metal. Also refers to fresh or
unoxidised material.
Rocks that overlie basement rock
A mineral deposit or enrichment formed near the surface.
The boundary zone between contrasting rock masses; the contact between continental plates
that have collided.
At the same time as deformation takes place.
Relates to the correlation of rock formations with each other in terms of their connection with
a tectonic event
A rock or group of rocks together with the area of an outcrop.
A type of basalt (igneous rock) which includes very little sodium as compared with other
basalts.
Low-angle reverse faulting/shearing.
A process that reduces the effect of isolated (and possible unrepresentative) outlier assay
values on the estimation.
Fault zone with a combination of strike-slip motion (parallel to the strike of the fault) and
compression during crustal deformation.
A rock composed of pyroclastic material ejected from a volcano.
Igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low
potassium and are composed of usually greater than 90% mafic minerals.
A tabular or sheet-like body of one or more minerals deposited in openings of fissures, joints, or
faults.
Combination of clastic rocks composed solely or primarily of volcanic materials and clastic noncarbonate sedimentary rocks that are almost exclusively silica bearing
The process by which rocks are broken down and decomposed by the action of wind, rain,
changes in temperature, plants and bacteria.
A surface or 3D volume formed by linking points together to form triangles. Wireframes are
used in the construction of block models.
P a g e | 64

Independent Geologist`s Report on the Mineral Assets of Polymetals

Transcription

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