The Tanami region has become one of Australia?s premier Proterozoic gold provinces, having already produced 4.85 Moz (150 t) of gold, and still has high exploration potential. This region contains more than 60 gold occurrences including three established gold fields (Dead Bullock Soak, The Granites and Tanami) as well as several significant gold prospects (Groundrush, Titania, Crusade, Coyote and Kookaburra). The Callie deposit (>4.5 Moz total resource) located in the Dead Bullock Soak goldfield is currently the largest mine in this region. The fluid inclusion data suggests that the deposits have formed over a range of physico-chemical conditions and depths. Groundrush appears to have formed at the greatest depths and has the most reduced (CH4-rich) fluids. The Granites goldfield and the Coyote and Callie deposits formed at shallower depths. The Coyote deposit contained both CO2-rich and CH4-rich fluid inclusions. Fluids at The Granites were CO2-rich but also had variable N2 and CH4. Fluids at Callie are relatively more oxidised with only CO2 and N2 being detected. The Tanami deposits appear to have formed at the shallowest levels and are dominated by low-salinity aqueous fluid inclusions, although some CO2-bearing fluid inclusions have also been detected. Thus, it appears that the ore-bearing fluids in the Tanami region attained temperatures between 120 and 430 ?C and contained variable quantities of CO2 ? other gases which may have formed as a result of fluid/rock interaction. Homogenisation data indicate that the Groundrush and Coyote deposits had the highest temperature fluids (260 ? 430 ?C), while the ore fluids in the Dead Bullock Soak and The Granites goldfields were moderate to high temperature (220 ? 326 ?C). In contrast, the Tanami goldfield, is dominated by low temperature (120 ? 220 ?C) aqueous inclusions. O and H isotopic data are consistent with either a metamorphic or magmatic origin for the ore fluids with some mixing with meteoric fluids evident in the Tanami district. In an effort to evaluate the regional extent of this gold-only mineral system we have carried out re-gional sampling of outcropping quartz veins and extended our fluid inclusion and Ar/Ar studies into the north Arunta region. More than 100 quartz vein clusters located in regions with differing metamorphic grade, were selected for sampling on twelve 1:250K mapsheets. The following types of veining have been observed: ? Epithermal veins with a range of textures including chalcedonic, colloform and comb quartz. ? Mesothermal veins striking mainly E-W. These veins are highly prospective as they are of a similar age to those in the gold deposits and have fluid chemistries similar to the ore-bearing fluids. ? Quartz veins with saccharoidal textures that contain two fluids: a higher temperature (230 ? 330 ?C), gas-rich fluid and a lower temperature (120 ? 230 ?C), saline, aqueous fluid. Acknowledgements This work forms part of the North Australia Project, a collaborative project between Geoscience Australia and the Northern Territory Geological Survey. TPM, GLF, and DLH publish with permission from the CEO of Geoscience Australia.

No abstract available

Situated just inboard of the late Neoproterozoic Australian rift margin (Tasman Line), the Broken Hill region occupies a critical position in reconstructions of Rodinia, combining an older basement (Willyama Supergroup) deformed by Paleoproterozoic-Mesoproterozoic events with a subsequent record of crustal extension, dyke intrusion and syn-rift sedimentation commencing around 827 Ma. These events not only constrain the timing and initial direction of late Neoproterozoic continental extension but provide a critical test of competing reconstructions for Rodinia in which south-central Australia is juxtaposed against western Laurentia. Contrary to some reconstructions there is no continuation of 1100-1300 Ma Grenville-age rocks into Broken Hill (SWEAT) and alternative restorations based on juxtaposition of the Broken Hill and Mojave-Oaxaca terranes along the Sonora-Mojave mega-shear (southern USA) result in misalignment of this major palaeo-transform fault with late Neoproterozoic normal faults in south-central Australia. Differences in deformational history and tectonic setting also preclude simple matching of 1.7-1.60 Ga orogenic belts in Australia and Laurentia (AUSWUS). In contrast to the southwest margin of Laurentia which was dominated by plate convergence, terrane assembly and arc magmatism throughout much of the Late Proterozoic (Yavapai and Mazatzal orogenies), the Willyama Supergroup preserves a record of 1.72-1.67 Ga intracontinental rifting and crustal extension (D1) followed by nappe emplacement and crustal thickening after 1640 Ma, culminating in the 1600 Ma Olarian orogeny (D2). Crustal thickening produced a second generation of granulite-grade mineral assemblages in the Willyama Supergroup and was superimposed on rocks initially metamorphosed under low P ? high T conditions as a result of D1 crustal thinning and associated bimodal magmatism. The resulting counterclockwise P-T-time path is evident only in the structurally higher parts of the Willyama Supergroup whereas the underlying and once more deeply buried parts of the sequence reveal evidence of decompression and metamorphism under progressively lower pressures as might be expected to occur during emplacement of a metamorphic core complex. A major mylonite zone of D1 age separates upper and lower structural levels. Validation of existing reconstructions for Rodinia requires a greater range of temporally equivalent events be present in western Laurentia than is presently recognised.

The Petrel Sub-basin Marine Survey GA-0335 (SOL5463) was acquired by the RV Solander during May 2012 as part of the Commonwealth Government's National Low Emission Coal Initiative (NLECI). The survey was undertaken as a collaboration between the Australian Institute of Marine Science (AIMS) and GA. The purpose was to acquire geophysical and biophysical data on shallow (less then 100m water depth) seabed environments within two targeted areas in the Petrel Sub-basin to support investigation for CO2 storage potential in these areas. The survey mapped two targeted areas of the Petrel-Sub-basin located within the Ptrl-01 2009 Greenhouse Gas acreage release area (now closed). Data acquired onboard the AIMS research vessel, Solander included multibeam sonar bathymetry (471.2 km2 in Area 1 and 181.1 km2 in Area 2) to enable geomorphic mapping, and multi-channel sub-bottom profiles (558 line-kilometres in Area 1 and 97 line-kilometres in Area 2) to investigate possible fluid pathways in the shallow subsurface geology. Sampling sites covering a range of seabed features were identified from the preliminary analysis of multibeam bathymetry and shallow seismic reflection data. Sampling equipment deployed during the survey included surface sediment grabs, vibrocores, towed underwater video, conductivity-temperature-depth (CTD) profilers and ocean moorings. A total of 14 stations were examined in Area 1 (the priority study area) and one station in Area 2. This report provides a comprehensive overview of the survey activities and preliminary results from survey SOL5463. Detailed analyses and interpretation of the data acquired during the survey will be integrated with new and existing seismic data. This new information will support the regional assessment of CO2 storage prospectivity in the Petrel Sub-basin and contribute to the nation's knowledge of its marine environmental assets.

This record describes digital data compilation product, where several individual items are grouped for delivery on single CD-ROM. Content and number of items included in the compilation package can vary, depending on size of the individual items. The contents of this CD-ROM are as follows: Catalog # Title 21173 NTdata, all mapinfo mapsheets

22-2/F52-4/2-6 Contour interval: 25

D52/B1-173 Vertical scale: 10

75% coverage south 22-3/D53-5/5-5 Vertical scale: 100

D54-B1-5371 Contour interval: 10

No abstract available