Uranium ore-forming systems of the - Geoscience Australia

Uranium ore-forming systems of the Lake Frome region3.4 RESULTS3.4.1 3D structureThe gross structural architecture of the Lake Frome region was largely established during thePaleoproterozoic to Mesoproterozoic basin-forming and orogenic events, followed byNeoproterozoic rifting. The Delamerian Orogeny variably affected the study area with intensedeformation and metamorphism recorded in the southern Curnamona Province (Broken Hillregion) and Mt Painter Inlier. The architecture of the pre-Delamerian Cambrian Arrowie Basin inthe study area was controlled by broadly north-south trending basin margin and intra-basin faultsincluding the Poontana Fracture Zone and faults at the margins of the northerly trending BenagerieRidge (Figs. 3.7, 3.8). This basement ridge bisects the basin into the Moorowie and Yalkalpo subbasins.The north-south trending fault sets appear to have been reactivated repeatedly since theearly Paleozoic, controlling younger sedimentation even as recently as the Quaternary.BRFigure 3.7: OZ SEEBASE image of depth to pre-Neoproterozoic basement for part of southernAustralia including the study area (rectangle), showing faults active during a stage (780-735 Ma) ofthe Neoproterozoic rifting event. Blue tones represent greater depth to pre-Neoproterozoic basementthan pink tones. The Benagerie Ridge (BR) and flanking Moorowie and Yalkalpo sub-basins arevisible in the image. Source: FrOG Tech (2006).Page 36 of 151