Re-examination of the Ordovician geology between Mandurama and Bigga in the Lachlan Orogen of central western New South Wales has produced new interpretations of the stratigraphy and structural geology. The Abercrombie beds have been previously inferred to comprise an Ordovician turbidite package with interbedded black shale bands. Although hampered by a paucity of fossil ages, new data suggest that the Ordovician geology of this region instead represents an imbricate stack of Lower Ordovician turbidites (Adaminaby Group) and Upper Ordovician black shales (Warbisco Shale). Structural data from the north of this region suggest that duplication occurred in a D1 event (with formation of broadly east-west to west-northwest-trending thrust slices or fold limbs) and was accompanied by formation of cleavage and isoclinal folds. Thrusting of the Adaminaby Group and Warbisco Shale over or under the Lower Ordovician Coombing Formation (southern part of the Molong volcanic belt) also occurred at this time. East-vergent imbrication and thrusting and formation of a regional near-meridional steeply west-dipping cleavage occurred in the D2 event, when D1 thrusts or folds were folded around overturned (east-vergent) D2 folds. These new data also suggest that there is a north-to-south gradient in the intensity of the D2 deformation, with D2 effects decreasing from south to north approaching the Lachlan Transverse Zone. Such a gradient mirrors similar but more subtle local changes from the north. Together, they imply that the Lachlan Transverse Zone was a major zone of weakness during north-south shortening that resulted in the formation of D1 structures but was relatively rigid in local areas during the regional D2 deformation that resulted from east-west shortening when it formed a major tear/accommodation zone. This D2 rigidity may be caused by strength imparted by the earlier emplacement of large (variably mineralised) intrusive/volcanic complexes along the transverse zone.

Melbourne Geelong LiDAR 2007

Geologic observations suggest two stages of hydrothermal activity at a number of presently subeconomic iron oxide copper-gold systems in the Olympic Dam district, eastern Gawler craton. They contain high-, and moderate- to low-temperature Fe oxide-rich hydrothermal alteration. The mineral assemblages include magnetite-calc-silicate-alkali feldspar ± Fe-Cu sulfides and hematite-sericite-chlorite-carbonate ± Fe-Cu sulfides ± U, REE minerals. In all documented prospects, the minerals of the hematitic assemblages replace the minerals of the magnetite-rich assemblages. The bulk of the subeconomic Cu-Au mineralization is associated with the hematitic alteration assemblages. Microanalysis by proton ion probe (PIXE) of hypersaline fluid inclusions in magnetite-rich assemblages, however, demonstrates that significant amounts of copper (>500 ppm) were transported by the early-stage high-temperature (>400C) fluids responsible for the magnetite-rich alteration. These brine inclusions contain multiple solid phases (liquid + vapor + multiple solids) including chalcopyrite in some cases. In comparison, inclusions of the hematitic stage are relatively simple liquid + vapor types, with homogenization temperatures of 200C to 300C and containing 1 to 8 wt percent NaCl equiv. The Br/Cl ratios of the magnetite-forming fluids measured by PIXE lie beyond the range of typical magmatic and/or mantle values, allowing for the possibility that the fluids originated as brines from a sedimentary basin or the crystalline basement. Sulfur isotope compositions of chalcopyrite and pyrite demonstrate that sulfur in both alteration assemblages was derived either from cooling magmas and/or crystalline igneous rocks carried by relatively oxidized fluids ({sum}SO42- {approx} {sum} H2S, {delta}34Ssulfides from +5 to +2{per thousand}) or from crustal sedimentary rocks ({delta}34Ssulfides from +5 to +10{per thousand}). Oxygen and hydrogen isotope compositions of waters calculated for minerals of the magnetite-rich assemblage have {delta}18O values of +7.7 to +12.8 per mil and {delta}D values of +15 to +21 per mil. The only available {delta}18O and {delta}Dfluid values for the hematitic assemblage are +4.7 and +9 per mil, respectively. The isotopic compositions of both fluids, coupled with the available literature data, can be explained in terms of fluid reequilibration with felsic Gawler Range Volcanics or other felsic igneous rocks in the region and with metasedimentary rocks of the Wallaroo Group at low water-to-rock ratios prior to their arrival at the mineralization sites. The lack of significant copper mineralization associated with magnetite-forming fluids that carried copper suggests that there was no effective mechanism of saturation of copper minerals or the quantity of these fluids was not sufficient to produce appreciable copper mineralization. Association of the copper-gold mineralization with the hematitic alteration in the subeconomic prospects can be explained by a two-stage model in which preexisting hydrothermal magnetite with minor associated copper-gold mineralization was flushed by late-stage oxidized brines that had extensively reacted with sedimentary or metamorphic rocks. The reduction of these brines, driven by conversion of magnetite to hematite, resulted in precipitation of copper and gold. The oxidized brines may have contributed additional copper and gold to the system in addition to upgrading preexisting subeconomic Cu-Au mineralization. When compared to published models for the Olympic Dam deposit, the new data for fluids in subeconomic Fe-oxide Cu-Au prospects of the Olympic Dam district indicate the diversity of origins of iron oxide-copper-gold systems, even within the same geologic region.

This suite of products relates to LiDAR data for the NSW Central and Hunter Coasts. The data was collected by Fugro Spatial Solutions Pty. Ltd. Under contract to the NSW State Government in January 2007. The survey was funded by the NSW Greenhouse Office (The Cabinet Office) with contributions from the Hunter Water Corporation and Lake Macquarie Council. LiDAR (Light Detection and Ranging) is an airborne remote sensing technique for rapid collection of terrain data. The sensor used for this LiDAR project collected XYZ and intensity data for two returns, first and last (ground) return by bouncing a pulse from the aircraft to the surface that enables the height and intensity values to be calculated. Survey report contains detailed information on capture and processing of LiDAR data Contract deliverable showing classified non-ground LiDAR strike returns recorded along survey flight lines. Point data records the surface elevation in metres AHD and intensity value of return. Data delivered as 1 square kilometre tiles for the entire survey area, a total of 1429 tiles covers the survey area. Survey report contains detailed information on capture and processing of LiDAR data. All data geo-referenced to GDA94/MGA56 and AHD. Survey report: Fugro Spatial Solution P/L, 2007, ALS Survey Report for Department of Planning (NSW) Central Coast, Fugro Spatial Solutions report J231335-20070309, March 2007.

The 2002 report to the Council of Australian Governments (COAG) <i>Natural disasters in Australia: Reforming mitigation, relief and recovery arrangements</i> advocated a 'fundamental shift in focus towards cost-effective, evidence-based disaster mitigation'. The report stated that in Australia there was a 'lack of independent and comprehensive systematic natural disaster risk assessments, and natural disaster data and analysis'. One key solution proposed to address this gap in our knowledge is outlined in Reform Commitment 1 in the report: <i>Develop and implement a five-year national programme of systematic and rigorous disaster risk assessments</i>. This framework is designed to improve our collective knowledge about natural hazard risk in Australia to support emergency risk management and natural hazard mitigation. The natural hazards covered are those defined in the report to COAG: bushfire, earthquake, flood, storm, cyclone, storm surge, landslide, tsunami, meteorite strike and tornado. Many events have demonstrated that the importance of natural hazards does not lie simply in the generation and passage of events such as severe storms or floods, but in the wide-reaching and profound impacts that these events can have on communities. Risk 1 is defined as: A concept to describe the likelihood of harmful consequences arising from the interaction of hazards, communities and the environment. This framework focuses on risk assessment for sudden onset natural hazards to underpin natural hazard risk management and natural hazard mitigation. The framework does not focus on risk management or mitigation, although its outcomes support and benefit these. The framework covers the following risks arising from natural hazards: financial, socio-economic, casualty, political and environmental risk. Each of these risks contributes to the overall impacts of natural hazards on communities . This framework is aimed foremost at those who seek an improved evidence base for risk management of natural hazards, in all levels of government. The framework is also intended for risk assessment practitioners, researchers and information managers. The primary driver of the framework is the need to develop an improved evidence base for effective risk management decisions on natural hazards. Developing this improved evidence base will also deliver on COAG Reform Commitment 1. Other key drivers include: - Cooperative approaches across all levels of government to managing natural hazards; - A consistent approach to natural hazard risk assessment; - Risk management for cross-jurisdictional and catastrophic disasters; - The potential impacts of climate change from possible changes in the frequency or severity of weather related natural hazards; - Increasing exposure of populations to natural hazards through demographic change and increases in personal assets.

Upgrade for software package for geochemical modelling released in 1999. Available from OEMD on request to Evgeniy Bastrakov (a password is set for a particular user).

Thomson-Lachlan seismic project Results and implications

Pb-Pb step leaching PhD Abstract

The presentation covers the following: - a brief review of GA's Onshore Energy Security Program - U systems and national projects - regional projects and the geophysical acquisition program - input into GA's plans for precompetitive data acquisition

This presentation was delivered at the Geothermal Energy Industry Roundtable at Parliament House in March 2007.