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Deposit Synonyms
COOPERS FIND; CTRITCHLEY; EMILY; FALCON; KAVANAGH; MATTHEW; ML 3612; ML 3624; ML 5776; ML 6324; ML 6345; ML 6436; NUGENT; PARINGA; SLOT-EXTENSION; SPITFIRE; VALENTINE; WHEAL FORTUNE
Mineral District
KANMANTOO COPPER-GOLD
Deposit Summary
KANMANTOO, a historic copper mine with mining periods between 1846-1874 Underground); 1971-1976 (open cut); 2011-2019 (open cut) and 2023-present (Underground). As of October 2024, resources were reported at 19.3Mt grading 0.77% Cu and 0.14 g/t Au, containing 150,000 t of Cu metal and 82,000 oz Au.
Deposit Description
An historic copper mine originally operated by ‘The South Australian Company’ between 1846-1874 to mine several pipe-like ore bodies down to depths of 60 m with sorted grades of 25 to 30% Cu shipped to Swansea, Wales, UK. Local smelting began in 1848, enabling treatment of ore of 12% Cu. Mining was halted in 1851 due to the Victorian gold-rushes and poor grades. Sporadic mining continued until 1874, with total production during this period from the Kanmantoo group of mines of 24 000 t @ 8.5% Cu. In 1938 a drilling program carried out by Austral Development Company, intersected 75 m @ 0.63% Cu, which was uneconomic at the time. the 1960s, regional exploration by Broken Hill South Ltd., through its subsidiary Mines Exploration Pty. Ltd., intersected 130 m @ 0.95% Cu in October 1962. An open cut mine to treat 750 000 tpa of ore was established in 1970. Plans to develop an underground mine below the open pit were abandoned and the mine closed in June 1976 due to continuing low copper prices. Approximately 4.1 Mt of ore @ 0.87% Cu and 0.07 g/t Au was mined from the open pit between 1971 and 1976. The mine was put into care and maintenance.
Exploration resumed in 2004 when Hillgrove Resources defined a cluster of eight Cu-Au-Ag deposits around the old Kanmantoo open pit. Resources in 2009 were estimated at 32.2Mt @ 0.9%Cu, 0.2g/t Au, and 3.2g/tAg, withy total contained metal, 292,200 t Cu, 191,100 oz Au, and 3,313,600 oz Ag. A potential resource of garnet from garnetiferous metasediment was identified grading >12% garnet, but this has not been persued. Open cut mining commenced in late 2011 and concluded in May 2019 with the pit reaching a depth from surface of 380 m. During this period the mine produced 137,000 t of Cu and 55,000 oz Au, before the mine was again placed on care and maintenance. In 2021 Hillgrove began planning for underground operations with construction of a decline commencing in November 2021. Underground production commenced in July 2024. As of October 2024, resources were reported at 19.3Mt grading 0.77% Cu and 0.14 g/t Au, containing 150,000 t of Cu metal and 82,000 oz Au from the Kavanagh-Spifire, Nugent, North Kavanagh and Emily Star orebodies. The current production rate of 1.4Mt p/a gives Kanmantoo an 8 to 10 year mine life. Hillgrove intend to increase production to 1.8 Mt p/a with the development of the Nugent orebody. Further drilling of the deposit has identified some high grade zonesincluding 18.55m @ 5.69% Cu & 1.02 g/t Au from 187m in drillhole 24KVUG0476 16m @ 2.96% Cu & 0.42g/t Au from 197m in drillhole 24KVUG0503. The deposits are located in the axial region of an upright Delamarian syncline, with the main mineralised pipe located on the E limb of the S-plunging syncline. Ore mineral paragenesis is early copper, late gold with weak copper. Mineralisation is accompanied by a large-scale alteration system with a significant Cu-Au geochemical footprint. The main Kavanagh lode, on which an open cut was developed on a complex series of pipe-shaped zones of Cu-(Fe-Bi-Au-Ag) mineralisation in host metasediment of the upper Tapanappa Formation. The origin(s) of mineralisation is contentious, with theories arguing for a metamorphic or metamorphogenic origin, also a pre-metamorphic origin as a sub-seafloor feeder zone to adjacent meta-exhalites near the Kanmantoo deposit. Mineralisation is largely controlled by a set of N-S and NE striking structures and is best developed where these 2 structural trends intersect. Main pipe is composed of multiple sulphide lenses paralleling the schistosity of the host. Immediate host to the ore is chlorite rich, comprising an assemblage of quartz-chlorite-garnet±pyrrhotite±chalcopyrite, forming a mineralised core within the garnet-andalusite schist host.
Discovery Year
~ 1845
Commodities
Copper, Gold, Silver, Garnet, Bismuth
Ore Minerals
Azurite, Bismuthinite, Chalcocite, Chalcopyrite, Cobaltite, Cubanite, Galena, Gold, Ilmenite, Mackinawite, Malachite, Marcasite, Molybdenite, Silver, Sphalerite, Wolframite
Gangue Minerals
Andalusite, Biotite, Chlorite, Garnet, Magnetite, Pentlandite, Pyrite, Pyrrhotite, Quartz, Staurolite
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