Marble in Ethiopia - gse.gov.et
Transcription
Marble in Ethiopia - gse.gov.et
EthiopienFS_MARBLE2_Ethiopia 1/4/11 3:29 PM Page 1 Marble has been mined in many parts of Ethiopia since ancient times and the deposits are inexhaustible. There is a wide range of colours and the quality is supreme. The quality is so good that Ethiopia has a significant export to the marble country par excellence of Italy. Numerous extensive deposits of marble are generally hill forming and occur throughout northern and western Ethiopia. The marble deposits are part of mediumgrade, metasedimentary successions of the different Precambrian greenstone complexes. The marbles occur as strikeparallel lenses (presumably reflecting fold patterns), intercalated with amphibolite, quartzite and schists. The metasedimentary rocks are affected by granitic, mafic and ultramafic intrusions. Most of the marble is white to grey, coarse-grained calcitic with calcite contents of 98%. All marble deposits are jointed and fractured. Locally the fracture systems are closely spaced but often joint systems occur with spacing between 2–3 m, making quarrying of large blocks feasible. Most marble deposits contain billions of tons of high-quality marble. The Ethiopian marbles vary within a large colour spectrum. Pure white marble is common together with grey, greenish, pink and sky blue varieties. Marble is quarried for a variety of architectural and artistic purposes in Ethiopia. In a large number of quarries, the marble is extracted by small-scale operations using hand-held drill hammers and wedges as primary tools, no sophisticated methods such as blasting and/or sawing are used. The maximum weight of blocks mined by small-scale enterprises is about one ton. In some of the marble quarries, for instance the large Daleti marble quarry, diamond chain sawing is used to produce very large blocks for export. Daleti Mankush Baruda (Moye, Gewi & Ekonte) Bulen & Ganzi Daleti Newi Naedir Akmara Kelafinos Taget Enda Tikur Berdada Lake Tana ft Addis Ababa t E an Ri oi p hi n ai M High-grade Precambrian Undifferentiated gneisses and schists Low-grade Precambrian Metavolcano-sediments Metaultramafic-mafics Precambrian Phanerozoic Intrusives Gabbro Diorite Granite-tonalite Palaeozoic Rocks Tillites Mesozoic Rocks Undifferentiated sediments Geology: Modified from Mengesha et al.(1996) Geological map of Ethiopia, second edition, 1:2,000,000 MINERAL RESOURCES OF Marble in Ethiopia Cenozoic Rocks Early-Mid Tertiary basalt Upper Tertiary-Quaternary - basalt Mid Tertiary-Quaternary - felsic rocks Early Tertiary sediment Upper Tertiary-Quaternary sediment Simplified geological map of Ethiopia with localities of marble the Western and Northern parts of the country. Some of the marble is used locally for dimension stones, whereas the main production is for export. One of the main importers of Ethiopian marble is Italy, known as the marble-producing country par excellence, which indicates that the imported Ethiopian marble matches the famous Carrara marble; for centuries the Carrara marble has supplied not only Europe but also other continents with high-class material for tiles, slabs and sculptures. Ethiopia is endowed with marble occurrences, a number of which have been explored and quality tested. So far only a limited number of marble deposits have been exploited, so the potential in Ethiopia for further expansion of marble production and export is huge. Daleti marble deposit The deposit is named after the town Daleti, 635 km west of Addis Ababa. The deposit is one of the best known marble deposits which have been exploited for a long period of time. The deposit is flat to hill forming and generally exhibits a variety of colours ranging from white, dark grey, pink, blue and green patches. The ‘multicolour’ blue and pink varieties are rare. The pink, silicate rich marble and sky blue marble occur around contact zones with basic dykes. Like the variations in colour, there are also different grain sizes: Coarse-grained marble with minor graphitic bands, coarsegrained graphitic marble with white bands and white fine-grained green to grey patches. The marbles are calcitic with minor amounts of dolomite, graphite, quartz and micas. This deposit is explored by the National Mining Company. The company uses highly sophisticated technologies where both cutting by diamond wire and water jet are applied. EthiopienFS_MARBLE2_Ethiopia 1/4/11 3:29 PM Page 2 Ministry of Mines of Ethiopia MINERAL RESOURCES OF Dear Investors, We take this opportunity to welcome you to Ethiopia. We promise to make every possible effort to provide you with all required information on the mineral sector in Ethiopia. Photo of Daleti marble outcrops in the foreground and a large forest clad hill of first class marble. If you require information on the mining law, licensing conditions and the invest- Mankush marble deposit This is a large marble deposit situated some 700 km west of Addis Ababa. It occurs in a Precambrian metamorphic complex consisting of metasedimentary rocks alternating with amphibolites. The complex has been deformed many times, subjected to highgrade metamorphism and later intruded by granites and a variety of ultramafic bodies. Most of the outcropping marble has joints with spacings up to 3 m and well suited for extracting large blocks. The Mankush marbles range in colours from white with grey veins, grey with white veins and locally to pink varieties. Dark graphitic bands are locally dominating. Some of the marble outcrops are explored by Ethio-marble Industry and Berta Construction. Large blocks are extracted by pneumatic hand-drill hammers, wedges and jacks. The extracted blocks are trucked to Addis Ababa for further processing. No large-scale mining has yet been initiated in this marble deposit in spite of its obvious high quality and easy accessibility. ment climate in Ethiopia, please contact the Mineral Licensing and Administration Department: Ministry of Mines Mineral Licensing and Administration Department P.O. Box 486 Addis Ababa, Ethiopia Tiles of marble from Mankush showing range of Tel. +251 11 6461214 colours on a background of sky blue marble. Fax +251 11 6463454 Email: information@mome.gov.et www.mome.gov.et Marble occurrences and deposits The marble occurrences are found within the Precambrian basement rocks of the country, especially in the low grade meta-sedimentary and meta-volcanics of northern(Kelafinos, EndaTikur, Newi, Akmara, Naedir, Berdada, Taget, Adiwoyane, Eminzong marble deposits), western (Mora and Bapuri, Bulen, Ganzi, Baruda, Mankush and Daleti marble deposits). These marble deposits are identified potential for dimension-stone supply. If you require information on the geology and mineral opportunities in Ethiopia, please contact the Geological Survey of Ethiopia (GSE): Geological Survey of Ethiopia P.O. Box 2303 Addis Ababa, Ethiopia Tel. +251 6 463325 Fax +251 6 463326 Quarry in Daleti marble where Email: Survey@ethionet.et huge blocks are extracted using www.geology.gov.et diamond chain saws. We are looking forward to your mining investment in Ethiopia. Prepared with assistance from GEUS. December 2010