Neighbouring the Paterson Project in the Eastern Pilbara region of Western Australia, the Company’s Oakover Project comprises nine granted exploration licences and six exploration licence applications held 100% by the Company. The Oakover Project is centred on the Oakover Basin, which is recognised as having the main elements of a significant base metal and manganese mineral province, including by previous explorers such as BHP and CRA Exploration. It is a large sedimentary basin, formed during extensional tectonic events above a metal-rich, predominantly mafic volcanic basement. These periods of extension and subsequent compression have provided opportunities throughout the Basin for focussed fluid flow within fault zones and along stratigraphic units through reactive host sequences, enabling mineralisation to occur in a variety of settings. This has established potential for the region to yield copper, manganese, cobalt, zinc and iron deposits.
Oakover and Paterson Project tenement location plan
Several mineralisation models have been developed by the Company for base metal mineralisation in the Oakover project, based on current observations and results of historic exploration. These include reduced marine facies hosted “Zambian-style” stratabound copper deposits, where copper is mobilised by oxidised brines from “red-bed” shales and deposited in environments either close to rifted basement margins or distal to basement in evaporites or carbonate algal mats. This model is applied to copper mineralisation at Oakover East (e.g. Bocrabee), where the base of the Tarcunyah Group is recognised as equivalent to the Broadhurst Formation - host to the Nifty Copper deposit.
Metasomatic hydrothermal copper deposit models are also applicable to mineralisation styles in the Oakover project, including at Western Star and a number of other less-advanced copper prospects, especially along the western margin of the Basin. The model, analogous to that derived for the Kennecott copper deposit in Alaska, invokes medium temperature hydrothermal fluids leaching copper from basement source rocks focussed along faults and depositing copper sulphides in reactive carbonate or black shale (reduced) host rocks.
Western Oakover Project tenements and targets
The Oakover Basin is also host to the world class Woodie Woodie Manganese mine, which has been a source of high grade manganese since the 1960s; as well as a number of other smaller producing mines (Nicholas Downs, Skull Springs, Davis River, Ant Hill). Manganese deposits occur as stratabound deposits, typically as lower grade mineralisation in Manganese Group shales and Pinjian Chert Breccia, or as high grade hydrothermal carbonate replacement mineralisation in the Carawine Dolomite. The Company has numerous early to advanced manganese prospects within the Project.
The same processes for manganese deposits are invoked to explain a number of hydrothermal, very high grade haematite iron deposits in the region (e.g. Blue Valley on E46/1069), with the predominance of iron over manganese interpreted to be a function of fluid chemistry and wall rock reactivity. Extensive units of Marra Mamba Formation are also mapped on the Oakover project tenements, representing potential for the discovery of direct shipping iron ore (DSO) (see Carawine's IPO Prospectus announced on 12 December 2017 for details).
Manganese-cobalt mineralisation is recognised as a potentially significant new source of cobalt and manganese feedstocks for the growing global battery market, and is therefore an important exploration target for the Company. Carawine has identified a number of significant cobalt-manganese prospects within its Oakover Project, including at the Xmas prospect where historic rock chip sampling has returned results of up to 0.31% cobalt mineralisation from outcrop within 1 km of strike, and at a number of other large and highly anomalous cobalt-manganese lag anomalies with associated high-grade rock chip samples (see ASX announcements dated 21 December 2017 and 26 March 2018 for further details).
Xmas region manganese and manganese-cobalt targets