Uranium ore-forming systems of the - Geoscience Australia

Uranium ore-forming systems of the Lake Frome regionBeverley deposit settingFour MiledepositsettingFigure 7.3: Schematic diagram of the conceptual geological model used for geochemical modelling ofthe Paralana Hot Springs and sandstone-hosted uranium mineralisation in the Beverley – Four Miledistrict. The blue to red arrows show the heating and cooling cycle of fluid related to the ParalanaHot Springs; the black arrows show the fluid flow in the present-day aquifers; the red zones showhypothetical zones of uranium mineralisation. Modified after Brugger et al. (2005) and HeathgateResources (1998; 2009). The schematic settings of the Four Mile and Beverley deposits are indicated.Geological constraints important for understanding the results of modelling are:1. The Beverley and Four Mile East deposits are hosted by sands of Paleogene and Neogeneages, respectively.2. The Beverley orebody is hosted by fluvial sands and shales of the Namba Formation. Most ofthe mineralisation is confined to the Beverley Sands which are underlain and overlain by theAlpha Mudstone and Beverley Clay, respectively.3. At Four Mile East mineralisation is hosted by fluvial sands of the Eyre Formation.4. As Beverley and Four Mile East deposits are hosted by sands of different ages, mineralisationat the two deposits has either resulted from one late Miocene event (corresponding to themaximum age of Beverley mineralisation) or two separate events (for example, late Paleogenefor Four Mile East and late Miocene for Beverley, although other timing scenarios arepossible – see Chapter 5).5. Provenance studies on sands hosting Beverley mineralisation show that the sands werederived from the reworking of Early Cretaceous glacial or glacio-lacustrine sediments(possibly in proximity to Mount Painter Inlier) originally sourced from Eastern Australia(Sprigg, 1986; Wülser et al., 2005).6. The Paralana Fault system was initiated in the Mesoproterozoic but underwent periodicreactivation, the latest of which was as young as ~4 to 5 Ma (Preiss, 1995; Quigley et al.,2007). The present-day relief is thought to have resulted from this latest tectonic activity.Page 82 of 151