22-1/F52-6/3

No abstract available

Contrasting fluid systems, chemical gradients and controls on largetonnage, high-grade Au deposits, Eastern Goldfields Province, Yilgarn Craton, Western Australia

Legacy product - no abstract available

Legacy product - no abstract available

Basin evolution of the Vlaming Sub-basin and the deep-water Mentelle Basin, both located offshore on the southwest Australian continental margin, were investigated using 2D and 3D petroleum system modelling. Compositional kinetics, determined on the main source sequences, were used to predict timing of hydrocarbon generation and migration as well as GOR evolution and phase behaviour in our 2D and 3D basin models. The main phase of petroleum generation in the Vlaming Sub-basin occurred at 150 Ma and ceased during following inversion and erosion episodes. Only areas which observed later burial have generated additional hydrocarbons during the Tertiary and up to present day. The modelling results indicate the likely generation and trapping of light oils for the Jurassic intervals for a variety of structural traps. It is these areas which are of greatest interest from an exploration point of view. The 2D numerical simulations in the Mentelle Basin indicate the presence of active hydrocarbon generating kitchen areas. Burial histories and generalized petroleum evolutionary histories are investigated.

Legacy product - no abstract available

22-1/E51-12/1 Contour interval: 5

G51/B1-83

Regional airborne electromagnetic (AEM) data provide valuable information for mapping the shallow crust. Data are particularly useful for mapping buried paleotopography including paleovalleys and paleochannels, showing the depth to conductive geological units (and perhaps related faults), and altered and weathered unconformity surfaces, that may be less evident in other regional datasets. Geoscience Australia (GA) has recently acquired and released regional AEM data in the Paterson area of Western Australia, which is one of the most highly prospective areas in Australia. GA is currently in the process of assessing the potential of basinal fluid-related uranium systems in the area, including unconformity-related, sandstone-hosted and calcrete-hosted systems. Interpretation uses this key dataset, along with other available geological, geophysical and remotely sensed data and publicly available drill hole data, Outputs of this assessment include a number of prospectivity maps for these uranium systems. Preliminary interpretations of the AEM data have identified paleovalleys containing Permian and younger sediments and fluid pathways as aquifers in Permian and younger sediments on-lapping the Rudall Complex, Fortescue Basin and Pilbara Craton. In some places, the AEM data map unconformities of Mesozoic over Permian and Permian over the Neoproterozoic Yeneena and Officer Basins and Mesoproterozoic Rudall Complex. The unconformity surface between the Neoproterozoic Yeneena and Officer Basin sediments over rocks of the Rudall Complex or Pilbara Craton appears poorly defined in the data. The AEM data are opening up new avenues of investigation for uranium systems and have shown the utility of flying regional AEM surveys over highly prospective areas.