Lake Gregory
Lake Gregory (EL 3976; EL 3977) -- Eromanga Region, South Australia
Location:
The Lake Gregory Project is situated in the Lake Eyre Basin, South Australia and approximately 150km northwest of Beverley, one of Australia's largest sandstone-hosted uranium deposits.The project cover a total area of 1,384km2 and is part of an extensive palaeo-drainage system spanning from Lake Frome in the southeast to Lake Eyre in the northwest. The system is marked by a distinct topographic depression, a series of lakes, lacustrine, fluvial and evaporitic sediments. This large palaeo-drainage system drained from the uranium-rich Mount Painter Region.
Exploration Activities:
A detailed airborne radiometric and magnetic survey for more than 20,000 line kms over the Lake Gregory project was undertaken by Fugro Airborne Surveys Pty Ltd in August 2008. Three broad clusters of anomalous Uranium were identified.
The principle target lithologies are sedimentary rocks within the Cretaceous Winton and Mackunda Formations, and pyritic and carbonaceous sands of the Palaeogene Eyre Formation, which hosts the significant Honeymoon uranium deposit.
The CET Study Suggested that since their deposition in the Cretaceous the sandy units accumulating in the Eromanga Basin would of acted as the conduit for uranium shredding from the uraniferous basement rocks of the Curnamona basement and formed deposits where suitably reducing conditions existed.
Proposed stratigraphic drilling has been approved for PACE Round 7 funding from the SA Government. Heritage approvals have been received from the Dieri People.
Exploration model:
The project areas cover part of a major palaeo-drainage system. Essential ingredients for uranium deposit formation are present: granties of the Mount Painter region (uranium source) that crop out approximately 100km south of Lake Gregory, palaeochannels and permeable strata (pathway for uranium transport) and reduced Cretaceous and Tertiary sequences (redox boundaries to promote uranium deposition). The exploration model is based on analogy with the Chu-Saryssu and Syrdarya uranium fields in Kazakhstan (estimated total resources of 1.14 million t U3O8) where economic sandstone-hosted uranium deposits occur up to 250km from the uranium source region.
