HIGHLIGHTS
- Located in the globally significant Callabonna Sub-Basin – home to multiple economic and actively mined uranium deposits.
- Mechanisms for uranium mineralising systems similar to regional deposits in Namba and Eyre Formations
- Contains a significant footprint of prospective paleochannels – hosts uranium mineralisation
Overview
The Frome project comprises four exploration licences, EL 6554 (Frome Downs), EL 6555 (Curnamona), EL 6703 (Erudina) and EL 6900 (Billeroo), covering a combined area of 3,037 square kilometres, located in the Frome Embayment of South Australia and just 12 km west of the Goulds Dam Uranium Deposit, which is owned by Boss Energy Ltd (ASX: BOE).
The Frome Embayment area is arguably the most prospective region in Australia for sandstone-hosted uranium deposits.
Figure 1: Pirie Basin Project and nearby Uranium deposits
Geology
The Frome project is situated in the south-western region of the Frome Embayment, bound to the west by Neoproterozoic sediments of the Adelaide Geosyncline, bound to the east by the Mesoproterozoic Benagerie Ridge and bound to the south by the Paleoproterozoic Willyama Supergroup of the Olary Ranges. The region comprises significant basin sedimentation of Proterozoic Adelaidean sediments, overlain by Cambrian sediments within the Moorowie Sub-basin and is unconformably overlain by Tertiary sediments of the Callabonna Sub-basin. Basement lithologies are inferred to comprise Paleoproterozoic Willyama Supergroup, Mesoproterozoic granite intrusives of the Ninnerie Supersuite (1,696 to 1,580 Ma), including the Crocker Well Suite granite (1,579+2 Ma) and volcanics of the Benagerie Ridge Volcanics (1,582+4 Ma).
The Frome project hosts a number of inferred palaeochannels, previously interpreted from regional electromagnetic surveys and drilling data, including: Curnamona Palaeochannel, Billeroo Palaeochannel, Erudina Palaeochannel (north and south), Frome Downs Paleochannel, Stickhole Paleochannel, and Wyambana Paleochannel.
At the Frome project there are the following key geological units:
- The Eocene Eyre Formation and the Miocene Namba Formation
- The underlying Arrowie Basin, which includes the hydrocarbon-bearing Wilkawillina Limestone
The Crocker Well Suite granite which is an excellent uranium source rock and displays a strong radiometric anomaly where it outcrops - Faults that cut both the Arrowie Basin sediments and the overlying Eyre and Namba Formations.
Uranium-rich source rocks, a permeable sandstone aquifer to carry the oxidised, uranium-bearing groundwater, and the introduction of a reductant along faults from a lower, hydrocarbon-bearing aquifer are all key technical characteristics required in this geological environment for potential economic uranium deposits.
Exploration
Early-stage exploration techniques, including passive seismic, induced polarisation (IP) and satellite gas (helium) studies, have enabled Orpheus to develop a deep comprehension of the mineralising system observed throughout the Frome Project. This work refined the distribution of the sedimentary channel systems, identified structural controls on depositional environments and further constrained the N-S trending redox characteristics of the project. Orpheus has inferred 12 kilometres of ‘redox fronts’ within palaeochannels, which are analogous to uranium mineralisation and form high-priority exploration targets. It also revealed multiple environments, where the geological, geochemical and geophysical characteristics are typical of “stacked” uranium roll-front mineralisation.
Orpheus has now devised a program of works designed to drill-test existing targets at the Erudina prospect and define the concealed paleochannel drainage systems and regional structures in detail for further target delineation.
Alongside our exploration, Orpheus has continued to engage with key stakeholders and progress the required processes for the Company to complete advanced-stage activities, including drilling.
