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Deposit Synonyms
ML 6471; RL 127
Mineral District
Deposit Summary
Cu-Au-Ag-U-(REE) mineralisation in host hematite breccia, brecciated gneiss & granite beneath ~470m of flat lying cover sediment. resource for S zone 203Mt @ 1.31%Cu, 0.56g/tAu, 6g/tAg, 270ppmU.
Deposit Description
CARRAPATEENA is hosted by strongly brecciated granitoid, variably foliated, sheared gneissic quartz-granite and quartz-diorite) dated at 1857±6 Ma and assigned to the Palaeoproterozoic Donington Suite. Regional setting is within the core of a NS-trending 30 x 100 km mass of granitoid overlain 10-15km to the W by ~1590 Ma mafic and felsic GRV. Cover is ~470m of flat lying Neoproterozoic sediment. Geophysical signature is a broad, weak and diffuse 200nT magnetic peak, and slightly offset, ellipsoidal, 3.5km diameter, 2 mGal gravity anomaly. The ore deposit occupies a NS-trending zone ~800 x 600 m at the unconformity surface with the underlying Palaeoproterozoic host rock. Mineralisation is confined to a steeply plunging, pipe-like body of hematite and hematite-granite breccia, the Carrapateena Breccia Complex (CBC), which is interpreted to be cut at its centre by an EW- to ENE-trending complex zone of faulting. To the N of this zone the mineralised mass is wedge-shaped, tapering rapidly downward into the fault zone and may conceivably follow that structure to depth.
The Carrapateena Breccia Complex (CBC) varies from heterolithic clast- to matrix-supported hematite-rich breccias. Many of the clasts are milled and rounded. The clasts are predominantly medium grained, gneissic diorite, with granite gneiss and vein quartz, variably altered to chlorite, sericite and hematite, as well as hematite-dominated clasts of earlier breccia phases within a matrix with a variety of textures that has also been altered to an assemblage of hematite, quartz and sericite. Higher grade copper intersections are typically associated with a grey hematite matrix within strongly brecciated granite. To the south, the CBC comprises an irregular, ~300-400m diameter, ellipsoidal-cylindrical mineralised body that has been traced by drilling from the unconformity to a depth in excess of 1km below that surface, and open at depth.
Mineralisation is zoned laterally outward, and to the north, vertically downward, from bornite to chalcopyrite-bornite to chalcopyrite to chalcopyrite-pyrite. 3 kernels of bornite-rich mineralisation have been delineated, one wedge-shaped zone to the NE that tapers southward into the inferred central zone of faulting, and 2 steeply plunging elongate zones, one above the other, in the upper and lower parts of the core to the main mineralised pipe-like mass of the CBC in the south. Principal alteration minerals are hematite, chlorite and sericite, with locally abundant quartz and carbonate (siderite and/or ankerite), and secondary barite, monazite, anatase, magnetite, apatite, fluorite and zircon.
Resource figure released in November 2013 was 800Mt @ 0.8%Cu, 0.3g/tAu, 3.3g/tAg, and 155ppmU at 0.3%Cu cutoff.
Discovery Year
? 2005
Commodities
Copper, Gold, Silver, Uranium Oxide, Rare Earths, Uranium
Ore Minerals
Argentite, Bornite, Chalcocite, Chalcopyrite, Gold, Rare Earths, Uranium Minerals (Non Specific)
Gangue Minerals
Hematite, Magnetite, Quartz
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