2012 Acreage Release information pack

Summary of GA's plans for marine seismic and reconnaissance surveys off southwestern Australia in 2008/09 as part of the Offshore Energy Security Program

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Overview of the Deep Crustal Seismic surveys conducted by Geoscience Australia and funded through the Onshore Energy Security Program since it's commencement in 2006 to September 2009.

Fluid escape features and their correlation with subsurface geology have been studied in the Capel and Faust basins, offshore Eastern Australia, as part of the petroleum prospectivity assessment of these frontier basins. New high resolution 2D seismic, gravity, magnetic and multibeam bathymetry data significantly improved the geological understanding of the area through imaging of the deeper structure of sedimentary depocentres and exposure of a wide range of seafloor features. Integration of seafloor features identified on multibeam bathymetry data with subsurface fluid flow pathways interpreted from seismic data provides insights into the nature of fluid flow mechanisms and seal integrity in the Capel and Faust basins. Seafloor features identified include mega-pockmarks, polygonal faults, buried mud-volcanoes, forced-folds above saucer-shape sills, and slope failures with associated debrites along basement bounding faults. The correlation between the distributions of modern bathymetric features and subsurface fluid flow pathways indicate that fluid flow has been mainly driven by Cenozoic igneous activity. The magmatism and fluid flow activity have implications for petroleum prospectivity. Ongoing magmatism, fluid flow and fault reactivation during the Cenozoic adds to the risk of hydrocarbon charge relative to regional seal formation and structure emplacement. Hydrocarbon accumulations that may have formed within the deeper syn-rift and the pre-rift sections are less likely to have been affected by the Cenozoic magmatic and fluid flow processes and, therefore, may represent lower-risk exploration targets.

A recent Geoscience Australia sampling survey in the Bight Basin recovered hundreds of dredge samples of Early Cenomanian to Late Maastrichtian age. Given the location of these samples near the updip northern edge of the Ceduna Sub-basin, they are all immature for hydrocarbon generation with vitrinite reflectance - 0.5% RVmax, Tmax < 440oC and PI < 0.1. Excellent hydrocarbon generative potential is seen for marine, outer shelf, black shales and mudstones with TOC to 6.9% and HI up to 479 mg hydrocarbons/g TOC. These sediments are exclusively of Late Cenomanian-Early Turonian (C/T) in age. The high hydrocarbon potential of the C/T dredge samples is further supported by a dominance of the hydrogen-rich exinite maceral group (liptinite, lamalginite and telalginite macerals), where samples with the highest HI (> 200 mg hydrocarbons/g TOC) contain > 70% of the exinite maceral group. Pyrolysis-gas chromatography and pyrolysis-gas chromatography mass spectrometry of the C/T kerogens reveal moderate levels of sulphur compounds and the relative abundances of aliphatic and aromatic hydrocarbons predict the generation of a paraffinic-naphthenic-aromatic low wax oil in nature. Not enough oom for rest of Abstract

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The Bureau of Mineral Resources, Geology and Geophysics (BMR) did a reconnaissance seismic survey in the central portion of the Bowen Basin in November, 1960. The objectives of the survey were to determine the structure of the Basin and the thickness of sediments by traversing from the western margin of the Basin near Anakie to the eastern margin east of Duaringa. Two other seismic surveys conducted in this Bowen Basin are Cooroorah Anticline seismic survey in 1959 (survey L037) and 254km seismic survey near the towns of Duaringa and Blackwater (survey L129).

Processed Stacked and Migrated SEG-Y seismic data and section images for the Youanmi Deep Crustal Seismic Survey. This survey was conducted under a National Geoscience Agreement with the Western Australia Geological Survey. Funding was through the Onshore Energy Security Program and Western Australia's Exploration Incentive Scheme. The objective of the survey was to image the northwest Yilgarn Craton to the Ida Fault crossing the Meekatharra structural zone, a focus of gold mineralization. Data are supplied as SEG-Y files, TIFF and PDF images. Raw data for this survey are available on request from clientservices@ga.gov.au

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