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Deposit Synonyms
OAK DAM
Mineral District
Deposit Summary
very thick, graded, resedimented hematitic breccia, similar to some upper sections of the Olympic Dam Breccia Complex. Davidson et al (Econ Geol, v102, 2007 pp 1471), do not comment on mineralization of the breccias complex.
Deposit Description
Oak Dam West iron oxide-copper-gold-uranium deposit was originally explored in 1986, along with the satellite Oak Dam East prospect. Due to its depth and higher priority targets at the time, the project remained on hold until a re-evaluation of the area in 2018, resulting in a subsequent drilling program that led to the discovery hole AD23.
Oak Dam West is hosted in the weakly to moderately deformed Donington Suite granitoid (~1.85 Ga), located below approximately 650 – 850m of post mineral cover. The main mineralisation event in the area is associated with magmatic-hydrothermal activity around 1585 – 1595 Ma.
The deposit is a hydrothermal breccia complex formed in a near-surface environment. It is believed to have formed following an early history of albite-calc-silicate ± magnetite formation (formed by hot hypersaline fluids), with progressive in-fill and replacement of the breccia by several alteration and mineralisation events. These resulted in variably intense hematite, sericite and chlorite alteration, and copper sulphide mineralisation. A strong structural overprint is present within the deposit, resulting in a N-S elongation and local faulting with minor to moderate offsets .
Oak Dam West has a pipelike core containing a barren hematite-quartz breccia (approximately central to the gravity anomaly), surrounded by high-grade chalcocite and bornite mineralisation, grading out to more dominant chalcopyrite and pyrite mineralisation towards the contact with the host granite.
The size of the Oak Dam West is around 1km by 3km with a current depth to around 2000m, with mineralisation starting from approximately 850m. Containing 1.34 Gt (as reported in July 2024) total resources of copper (@ 0.66%) and gold (@ 0.33 g/t).
Discovery Year
? 2018
Commodities
Copper, Gold
Ore Minerals
Bornite, Chalcocite, Chalcopyrite
Gangue Minerals
Siderite
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