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Kimpe |
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Katanga, Dem. Rep. Congo |
| Main commodities:
Cu Co
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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All papers now Open Access.
Available as Full Text for direct download or on request. |
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The Kimpe copper deposit is located ~65 km south-east of Lubumbashi, Katanga Province in the Democratic Republic of Congo (DRC)
The deposit is one of a group of relatively minor sediment hosted copper deposits on the northern rim of the Luina Dome,near the DRC-Zambian border, hosted by the Upper Roan Sub-group. For details of the regional setting and a geological location map, see the separate Central African Copperbelt - Congolese/Katangan Copperbelt and Zambian Copperbelt records.
The generalised stratigraphic succession of the host Roan Group meta-sediments in the deposit area is as follows, from the base, where it unconformably overlies metamorphic rocks of the Palaeoproterozic Lufubu Complex:
• Conglomerate, quartzite, argillaceous siltstone, chlorite schist and related facies
• Dolostone, and talcose-, siliceous- and argillaceous-dolostone, which comprises the mineralised suite;
• Gritty shales;
• Dolomitic shale and siltstone;
• Black shales.
The host sequence is tightly folded, with the mineralised zone forming a composite elongate tabular body with a northwesterly strike. It lies on the western limb of a reclined antiform that plunges at 55°due south and dips at ~50°W. This structure has a closure to the NW. Three phases of deformation have been recognised, reflected by cleavages S1, S2 and S3. The earliest cleavage S1, which forms the most penetrative structural grain, is axial planer to F1 folds and is sub-parallel to the bedding plane S0. Cleavages related to the F2 folding, are a crenulation-type, and has a NW-SE axial orientation. The F1 axial plane dips at from 50 to 80°SW, while the plunge of the fold axis varies from 50°SW to 55°W. The F3 folding also produced an axial planar crenulation cleavage, S3, superimposed on the F2 folds, striking from 280 to 80° and dipping steeply to the south. These folds have a moderate to steep easterly plunge. The combination of these fold phases had produced a complex pattern of flattening, extension, partial brecciation and shearing with marked variation between thicknesses on limbs and closures.
Mineralisation is hosted by dolostone and siliceous-, talcose- and argillaceous-dolostones, as described above. Field relationship between the different lithofacies suggests they belong to the same stratigraphic member and that there is an overall stratigraphic control on mineralisation. The mineralisation, which occurs as both sulphides and oxides/carbonates, forms dislocated pinch and swell and 'torn-out' lensoid bodies stretched out along the F1 axial trace (McDonald, 1970) and displaced by dextral NE-SW faults. These lenses, which vary from 2 to 15 m in thickness (at a 0.5% Cu cut-off), typically occur within the dolostone lithofacies package which is bounded on both the hanging- and footwall sides by thin carbonaceous phyllite, passing out on both sides into dolomitic shale with sandstone/quartzite interbeds. The orientation of the ore lenses varies from 325° and dip of 35° E to 320° and dip of 40°, which parallel the S1 and S2 cleavage planes respectively. The thickest mineralisation occurs at the intersection of SI and S2 planes, forming a pipe like body.
The principal 'ore minerals' include chalcopyrite, pyrite, pyrrhotite, malachite, azurite, covelite and bornite, which occur as veins, disseminations, patches and along zones of fracturing that have multiple orientations. The copper mineralisation is preferentially localised within the dolostone lithofacies, with the various forms following stratification, as well as the S1 and S2 cleavages. Sulphide mineralisation first appears at depths of 50 to 60 m below surface, above which carbonates and oxides predominate. The carbonaceous phyllites and shales are also weakly mineralised.
JORC compliant Mineral Resources quoted by Singh et al. (2013) are as follows to a depth of 150 m and 0.5% Cu cut-off:
Indicated Resource - 5.6065 Mt @ 1.68% Cu, 0.13% Co;
Inferred Resource - 2.5433 Mt @ 1.58% Cu, 0.09% Co;
TOTAL Resource - 8.9298 Mt @ 1.65% Cu, 0.12% Co;
Additional possible, non-JORC compliant resource potential quoted are:
to 150 m depth - 0.78 Mt @ 2.9% Cu, 0.13% Co;
to 225 m depth - 4.59 Mt @ 1.61% Cu, 0.12% Co;
Potential total, JORC + non-JORC compliant resource to 225 m depth - 13.52 Mt @ 1.71% Cu, 0.12% Co.
This summary is drawn from Singh et al. (2013).
The most recent source geological information used to prepare this decription was dated: 2013.
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.
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Singh, N.N., Gaur, M.K. and Gahlot, B.S., 2013 - A Note on Kimpe Copper-Deposit, Katanga, Central Africa: in Journal of the Indian Geological Congress 2013, v.5 (2), pp.33-41.
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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.
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