|
Damang |
|
|
Ghana |
| Main commodities:
Au
|
|
 |
|
|
 |
Super Porphyry Cu and Au
|
IOCG Deposits - 70 papers
|
All papers now Open Access.
Available as Full Text for direct download or on request. |
|
|
The Damang gold mine is located some 25 km North-east of the gold mining town of Tarkwa in south-western Ghana, and 200 km to the west of the capital Accra.
The ore is hosted by the Lower Proterozoic Tarkwaian clastic fluviatile sediments that overlie the older, metamorphosed Lower Proterozoic greywackes and mafic meta-volcanics of the Birimian Series. Both suites are part of the more extensive Man-Leo Shield which comprises Archaean and Proterozoic rocks that were once part of a larger craton in West Africa and Brazil. The deposit lies on the eastern margin of one of a number of NE trending belts of Birimian volcanics that are un-conformably overlain by synclinal belts of Tarkwaian sediments. Both the Birimian and Tarkwaian have been progressively deformed, culminating in overturning and over-thrusting on both edges of the belt.
Within the district the Tarkwaian sediments are characterised by extensive conformable blankets of mineralised conglomerate ("bankets"), believed to represent metamorphically modified palaeo-placer accumulations (typified by the Tarkwa mine as described below). The Damang deposit is unusual for the Tarkwaian in that it comprises a free milling hydrothermal quartz-vein stockwork. Similarly Birimian lode gold deposits (typified by Obuasi as described below) are not developed to any significant extent in the Tarkwa district, and are geochemically very distinct from the mineralisation in the Tarkwaian rocks.
Most mineralisation at Damang occurs in the core and on the eastern limb of the Damang Anticline, a long attenuated structure, bounded on both sides by strike faults. Gently east dipping to flat lying lenticular quartz veins make up ladder like sets of east dipping mineralised zones. These veins have selvages of pyrite and pyrrhotite, while disseminated sulphides are found through the hosts in the more heavily veined areas. The hosts are steeply east-dipping quartzite (ex-sandstone) and conglomerate, although in the hangingwall iron rich laminated staurolite-tourmaline meta-sediments and overlying finer grained meta-sandstones are also mineralised. Better grades are found in the vein system where it is developed within the conglomerate units that are the hosts to the stratabound mineralisation (bankets) found elsewhere in the
district.
The Damang mine was commissioned in 1997 after an expenditure of USD 135 million. In the 12 month period to June 1999 it produced 8.38 t (0.27 Moz) of gold from 3.73 Mt of ore averaging 2.37 g/t Au, with a metallurgical recovery of 95%.
In March 1999 the reserve and resource figures were (Ranger Minerals Ltd, 2000):
proved + probable reserves - 33.8 Mt @ 2 g/t Au at a 1.6 g/t Au cut-off, plus,
the total resource - 60 Mt @ 2.09 g/t Au at a 1 g/t Au cutoff for 125 t (4.03 Moz) of contained Au.
At 31 December, 2006, reserve and resource figures were (Gold Fields Ltd, 2007):
measured + indicated + inferred resources - 51.0 Mt @ 2.1 g/t Au for 109 t Au, including,
proved + probable reserves - 22.6 Mt @ 1.8 g/t Au for 41.5 t Au,
The mine was initially developed and operated by Abosso Goldfields Ltd which is owned 90% by Ranger Minerals Ltd and 10% by the Government of Ghana. It is now part of Gold Fields Limited.
The most recent source geological information used to prepare this decription was dated: 2001.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Damang
|
|
|
|
Anonymous 1999 - Damang: in Register of African Gold 1999/2000 pp 105-106.
|
Hatch D, Marston R 1999 - The Damang Gold Mine, Two Years On: in African Mining: Exploration and Investment Opportunities Conference, Perth, Australia: 16-17 November, 1999 AJM, Sydney 13p
|
Marston R, Woolrich P 1998 - Discovery and Development of the Damang Gold Deposit, Ghana, West Africa: in Facer R A (Ed) 1998 Exploration & Mining in Africa AIG Bull. 21 pp 63-75
|
Pigois J-P, Groves D I, Fletcher I R, McNaughton N J, Lawrence W S 2003 - Age constraints on Tarkwaian palaeoplacer and lode-gold formation in the Tarkwa-Damang district, SW Ghana: in Mineralium Deposita v38 pp 695-714
|
Reisberg, L., Le Mignot, E., Andre-Mayer, A.-S., Miller, J. and Bourassa, Y., 2015 - Re-Os Geochronological Evidence for Multiple Paleo-Proterozoic Gold Mineralizing Events at the Scale of the West African Craton: in Andre-Mayer, A.-S., Cathelineau, M., Muchez, P., Pirard, E. and Sindern, S., (Eds.), 2015 Mineral Resources in a Sustainable World, Proceeding of the 13th Biennial SGA Meeting, 24-27 August 2015, Nancy, France, v.4, pp. 1655-1658.
|
Tunks A J, Selley D, Rogers J R, Brabham G, 2004 - Vein mineralization at the Damang Gold Mine, Ghana: controls on mineralization: in J. of Structural Geology v26 pp 1257-1273
|
|
Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
|
Top | Search Again | PGC Home | Terms & Conditions
|
|
