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Gidgee - Kingfisher |
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Western Australia, WA, Australia |
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Au
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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 Gidgee gold deposit is located 120 km south-east of Meekatharra and 82 km north of Sandstone in the Gum Creek greenstone belt and Black Range gold district of the East Murchison Mineral Field, within Southern Cross Domain of the Yoaunmi Terrane,Archaean Yilgarn Craton, Western Australia.
The Gum Creek Greenstone Belt is similar to the other greenstone belts of the Southern Cross Province, occurring as a NNW trending synclinorium with basal metamorphosed mafic and ultramafic intrusives and extrusives interbedded with major banded iron formation units. These are overlain by poorly exposed, deeply weathered intermediate to felsic metavolcanics and metasediments which host the Gidgee gold deposit. Two granitoid masses of biotite adamellite (quartz-monzonite) are found within 10 km of Gidgee.
The ore at Gidgee (in the Emu Feather, Swan Bitter, Wren and North End deposits) is exclusively within the weathered/lateritic zone, although insufficient drilling was available in 1990 to discount primary mineralisation also. The profile comprises an upper 1 to 5 m of partially indurated coarse rubble and pisolitic material with patches of ferruginous and calcareous duricrust overlying a 60 to 70 m thick saprolite.
The known gold deposits are present as lensoid zones and pods of quartz-goethite-limonite vein swarms and stockworks with some lateral spread of gold into the host rocks. The ore zones generally parallel the regional strike, but do cut across lithological boundaries. Individual veins are not parallel to schistosity. In the primary zone the hosts are a carbonated (ankerite) basalt and veins of quartz and carbonate with tourmaline, pyrite and arsenopyrite.
The total pre-mining reserve in 1986 was - 2 Mt @ 3.38 g/t Au.
The Kingfisher deposit is some 3 km SSE of the main Gidgee group of deposits. It is hosted by a highly fissile banded sericite-carbonate schist immediately adjacent to the regional scale NW (325°) trending, 60° SW dipping Kingfisher Fault. The hangingwall is an amygdaloidal high Mg basalt, while the footwall is composed of interbedded basaltic flows and tuffs. Mineralisation is directly related to quartz veining, the most significant of which are 0.3 to 4 m thick with the highest gold grades at the hangingwall contact, while a 15 m wide zone of quartz-ankerite vein stockwork development is in the footwall. Pyrite is the main sulphide (generally < 1%) as fine disseminations and coarse euhedral crystals, although it may make up nearly 20% of the veins locally. Visible gold is usually associated with the coarse pyrite. Weathering extends to a depth of 120 m adjacent to the orebody. Gold from the primary zone has been remobilised to form a supergene blanket commencing at approximately 30 m and extending to the base of extreme weathering at 70 m. Most of the open pit ore came from this interval.
The total pre-mining measured resource in 1990 was - 1.46 Mt @ 4.5 g/t Au. (lower and upper cut-off limits of 1 and 30 g/t Au).
Production at the cessation of mining in 1996 was - 2.01 Mt @ 4.1 g/t Au (open pit) and 0.06 Mt @ 14.1 g/t Au (underground).
For detail consult the reference(s) listed below.
The most recent source geological information used to prepare this decription was dated: 1997.
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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Hazard N J 1998 - Kingfisher gold deposit, Gidgee: in Berkman D A, Mackenzie D H (Ed.s), 1998 Geology of Australian & Papua New Guinean Mineral Deposits The AusIMM, Melbourne Mono 22 pp 123-126
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Otterman D W 1990 - Gidgee Gold deposits, Jonesville: in Hughes F E (Ed.), 1990 Geology of the Mineral Deposits of Australia & Papua New Guinea The AusIMM, Melbourne Mono 14, v1 pp 267-271
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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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