Uranium ore-forming systems of the - Geoscience Australia

Uranium ore-forming systems of the Lake Frome regiondrove fluids through the permeable units of the previously deposited Namba Formation. Finally,the current topographic head is the potential energy source for fluid flow through the WillawortinaFormation and potentially also into underlying aquifers such as the Namba and Eyre Formations.Thus the interplay of climatic and tectonic evolution may influence the region’s potential for largeuranium mineral systems. These mineral system scenarios are explored in more detail in Chapter5 (section 5.4), Chapter 7 and Chapter 8.3.3 STRUCTURAL ARCHITECTURE AND BASIN FILL GEOMETRY3.3.1 Data compilation for 3D geological map constructionThe Lake Frome region has been a focus for uranium exploration since the late 1960s (Curtis etal., 1990), and extensive historical exploration data exists in various analogue and digital forms.Through the compilation and modelling of seismic, lithological, hydrological and drill log datawith modern computing software it is possible to provide new insights into the three-dimensionalstructure and chemical architecture of this important uranium province.To better understand the fault and lithological architecture within the study area a 3D model wasconstructed using gOcad software. The following datasets were integrated into the Frome 3Dmap:The 9 second AusDEM v2 (Geoscience Australia, 2002) with 270 m and 90 m pixelresolution, respectively. As both DEMs are national datasets they were converted fromgeographic coordinates (latitude and longitude, Geocentric Datum of Australia 1994) toeastings and northings (MGA94, zone 54). The DEMs were clipped to cover the projectarea. Due to limitations in computer resources, only the 9 second AusDEM was convertedinto a gOcad 3D surface. A portion of the new 1:1,000,000 scale surface geology of Australia (Raymond, 2009)was extracted for the study area and imported into gOcad as curves (Fig. 3.2).Seismic data were obtained from PIRSA as ‘segy’ format and imported into gOcad(Appendix 2 and Fig. 3.2).Drill hole data for the study area were compiled from public domain databases held bythe South Australia, New South Wales and Queensland geological survey agencies (Fig.3.2).Cultural and physiographic datasets, such as roads (GEOMET 2391), railways (GEOMET2390), population centres (Gazetteer database, Geoscience Australia, 2005), landuse(GEOMET 3415), drainage (Lawford, et al., 2007), state boundaries (GEOMET 2383)and physiography (GEOMET 2383) were compiled.Deposit and mineral occurrence information came from two Geoscience Australiadatabases: OZMIN mineral deposits database (Ewers et al., 2002) and the MINLOCdatabase.Page 21 of 151