The GILMORE Project (Geoscience In Land Management and Ore System Research for Exploration) is a pilot study designed to assess methodologies and technologies for identifying mineral prospectivity and dryland salinity in areas of complex regolith cover (Lawrie et al., 2000). The project area (100 x 150 km) lies in the eastern part of the Murray-Darling Basin in central-west NSW and straddles the Gilmore Fault Zone, a major NNW-trending crustal structure that separates the Wagga-Omeo and the Junee-Narromine Volcanic Belts in the Lachlan Fold Belt. Included in the project area are tributaries of the Lachlan and the Murrumbidgee Rivers. A critical aspect of this research was to develop databases and a GIS to enable researchers to view and analyse complex datasets and their inter-relationships in both two and three dimensions. The GILMORE Project GIS consists of 11 CDs in 2 volumes. Volume 1 is comprised of 5 CDs and contains airborne electromagnetic (AEM), magnetic and gamma-ray spectrometric geophysical datasets. These are included in point located (line) form as ASCII column format files, and in gridded form as ERMapper format grids. These data have already been released. Volume 2 comprises of 6 CDs containing data in ESRI\222s ArcInfo and ArcView for mat. Each CD has an ArcView Project accessing colour geophysical images (created in ERMapper), ArcInfo polygon, point and line coverages, ArcView shape files, with links to gif images, photos and .dbf files. The GIS will also be released in MapInfo format.

Airborne electromagnetic (AEM) systems are increasingly being used for mapping conductivity in areas susceptible to secondary salinity, with particular attention on near-surface predictions (ie those in the top 5 or 10 metres). Since measured AEM response is strongly dependent on the height of both the transmitter loop and receiver coil above conductive material, errors in measurements of terrain clearance translate directly into significant errors in predicted near-surface conductivity. Radar altimetry has been the standard in airborne geophysical systems for measuring terrain clearance. In areas of agricultural activity significant artifacts up to five metres in magnitude can be present. One class of error, related to surface roughness and soil moisture levels in ploughed paddocks and hence termed the ?paddock effect?, results in overestimation of terrain clearance. A second class of error, related to dense vegetation and hence termed the ?canopy effect?, results in underestimation of terrain clearance. A survey example where terrain clearance was measured using both a radar and a laser altimeter illustrates the consequences of the paddock and canopy effects on shallow conductivity predictions. The survey example shows that the combination of the dependence of AEM response on terrain clearance and systematic radar altimeter artefacts spatially coincident with areas of differing land-use may falsely imply that land-use practices are the controlling influence on conductivity variations in the near surface. A laser altimeter is recommended for AEM applications since this device is immune to the paddock effect. Careful processing is still required to minimise canopy effects.

The Ord Valley Airborne Electromagnetics (AEM) Interpretation Project was undertaken to provide information in relation to groundwater salinity management in the Ord River Irrigation Area (ORIA), and to assess the salinity hazard in areas of potential irrigation expansion. Salinity hazard maps were produced using an informed GIS-based approach. The salinity hazard maps combined AEM-derived maps of the shallow alluvial sediments, salt stored in the unsaturated zone and maps of groundwater salinity, with drilling data and maps of depth to the watertable. Hydrographic analysis showed that under current climate conditions, water tables were rising, and it was therefore assumed for GIS modeling purposes that water levels would continue to rise after land clearing and the onset of irrigation. It was also assumed that if shallow watertables developed at some time in the future, that salt accumulation through capillary rise (if within 2m of the surface) may lead to salinisation. This assumption was informed by prior geochemical modeling that inferred that if relatively modest groundwater salinity levels (>750 mg/l TDS) were evapo-concentrated that it may cause a significant salinity hazard to irrigated agriculture. Salinity hazard was assessed as high where there were significant quantities of salt stored in the alluvium in areas of shallow groundwater, and lowest where there is little or no salt stored in alluvium and groundwater tables are deep. The salinity hazard was forecast to be high to very high in the Mantinea Plain, Carlton Hill, Parry's Lagoon and lower Ord Floodplain areas. In the Knox Creek and Keep River Plains, the hazard was low in the north of the area, but moderate to high in the southern-central and areas of the southern Knox Creek Plain. In the priority development area (Weaber Plain), the salinity hazard was estimated to be highly variable.

An inventory of saline water disposal basins, Murray Basin : volume 3 additional basins in South Australia, Victoria and New South Wales 1998.

The role of palaeovalley evolution in the manifestation of salinity across the Australian continent P.M. English1 & J.W. Magee1, 2 1Geospatial & Earth Monitoring Division, Geoscience Australia, GPO Box 378, Canberra, ACT 2601 Pauline.English@ga.gov.au 2Department of Earth & Marine Sciences, Australian National University, Canberra, ACT 0200 jwmagee@ems.anu.edu.au Networks of palaeovalleys characterise much of arid, semi-arid and sub-humid Australia, including widespread rangelands and agriculturally important regions. These ancient river valley systems are very commonly the focus of salinity across our landscape, both primary salinity (Quaternary salt lakes and associated saline landforms), and secondary salinity in regions that have been cleared for agricultural development in the last 150 years. The preservation of palaeovalleys is a legacy of the continents tectonic stability, low relief and slow erosion and sedimentation rates. Palaeovalleys drain all the cratonic blocks and extend from Precambrian basement uplands across Palaeozoic, Mesozoic and Cainozoic sedimentary basins. They are now largely filled with Tertiary, or older, sediments and are commonly blanketed with Quaternary lacustrine, alluvial or aeolian sediments, including saline sediments and salts. While the palaeovalleys and their sedimentary infill are relatively ancient (early to mid Tertiary) the groundwater systems they host have evolved during latest Tertiary and Quaternary times. Salt began to concentrate in these palaeovalley networks and surrounding hinterlands from as long as 350 000 years ago, in response to glacial-interglacial cyclicity driven by global climate regimes. More recent salt accumulation in the historic period is the consequence of hydrologic disequilibrium wrought by land clearing which has caused broad-scale mobilisation of ancient salt stores into topographic lower areas and waterways in agricultural regions. Sodium chloride (NaCl) is the dominant salt in the Australian terrestrial environment, in both the arrays of ancient salt lakes and in secondary salinised agricultural regions. This reflects the dominance of marine aerosol source of salts in our rainfall and the longevity of salt accumulation in the near-surface environment. The marine signature is further pronounced in the case of primary salinity occurrences, where calcium sulphate, or gypsum (CaSO4.2H2O), is prevalent across the inland landscape. The ubiquity and solubility of NaCl and its mobility in shallow groundwater systems accounts for the recurrence and concentration of salinity in palaeovalley systems in particular. The persistence of ancient palaeovalley networks and of marine-derived salts in the salinised Australian landscape forms the basis of comparisons with southern Africa, for example, where tectonism and a significantly higher proportion of terrestrially-derived salts predispose contrasting manifestations of salinity. Such comparisons provide some insight and a broad perspective relevant to Australias contemporary salinity issues.

This study grew out of the GILMORE project, which is a pilot study designed to test methodologies and technologies for assessing mineral prospectivity and dryland salinity in areas of complex regolith cover (Lawrie, 1999; Apps et al., this volume). The project area is in central NSW, towards the eastern margin of the Murray-Darling Basin, straddling the catchments of the Lachlan and Murrumbidgee. The area can be divided into two parts, with creeks (eg. Bland creek) in the northern catchment flowing towrds the Lachlan River, and creeks in the southern catchments flow towards the Murrumbidgee River. The GILMORE project utilised a multi-disciplinary approach to generate a coherent picture of the various factors controlling the distribution of sediments and the saline groundwater. Thus, geomorphology and landscape processes (past and present), sedimentary environments, pedology, weathering and regolith formation, geophysical attributes of regolith materials and groundwater characteristics were all considered (Lawrie et al., 2000). The project has acquired a wide range of data, including airbone geophysics such as high-resolution magnetics, radiometrics and electromagnetics (AEM, TEMPEST system), as well as ground based (down-hole) geophysics, and information from 6600 drill holes of which 4000 have lithological and geological data (Apps et al., this volume). In addition, there is groundwater chemistry data of over 100 bore holes (Lawrie et al., 2000). Specifically, AEM surveys have been flown across areas 1 and 2 and AEM depth slice images have been utilised to establish the spatial pattern of conductivity and inferred distribution of saline groundwater and preferential groundwater pathways. This study aims to establish the association between mineral composition, lithology units and groundwater chemistry.

The map shows salt lake regions favourable for lithium deposits. For a more detailed description of selection method see Jaireth et al (2013)

In addition to typical seafloor VHMS deposits, the ~3240 Ma Panorama district contains contemporaneous greisen- and vein-hosted Mo-Cu-Zn-Sn occurrences that hosted by the Strelley granite complex, which drove VHMS circulation. High-temperature alteration zones in volcanic rocks underlying the VHMS deposits are dominated by quartz-chlorite±albite assemblages, with lesser low-temperature quartz-sericite±K-feldspar assemblages, typical of VHMS hydrothermal systems. Alteration assemblages associated with granite-hosted greisens and veins, which do not extend into the overlying volcanc pile, include quartz-topaz-muscovite-fluorite and quartz-muscovite(sericite)-chlorite-ankerite. Fluid inclusion and stable isotope data suggest that the greisens formed from high temperature (~590C), high salinity (38-56 wt % NaCl equiv) fluids with high densities (>1.3 g/cm3) and high -18O (9.3±0.6-), which are compatible with magmatic fluids evolved from the Strelley granite complex. Fluids in the volcanic pile (including the VHMS ore-forming fluids) were of lower temperature (90-270C), lower salinity (5.0-11.2 wt % NaCl equiv), with lower densities (0.88-1.01 g/cm3) and lower -18O (-0.8±2.6), compatible with evolved Paleoarchean seawater. Fluids that formed the quartz-chalcopyrite-sphalerite-cassiterite veins, which are present within the upper granite complex, were intermediate in temperature and isotopic composition (T = 240-315C; -18O = 4.3±1.5-) and are interpreted to indicate mixing between the two end-member fluids. Evidence of mixing between evolved seawater and magmatic-hydrothermal fluid in the granite complex, along with a lack of evidence for a magmatic component in fluids from the volcanic pile, suggest partitioning of magmatic-hydrothermal from evolved seawater hydrothermal systems in the Panorama VHMS system, interpreted as a consequence swamping of the system by evolved seawater or density contrasts.

Legacy product - no abstract available

<div>This data package provides petrophysical interpretations by Geoscience Australian and the South Australia Department for Energy and Mining (SADEM) for 23 wells generated in support of the energy resource assessments under the Australia’s Future Energy Resources (AFER) project in the Pedirka and western Eromanga basins. Interpreted petrophysical data in this data package include [BB1]&nbsp;[MB2]&nbsp;volume of clay/shale, porosity (total and effective), relative permeability, formation water salinity (NaCl equivalent), and apparent resistivity of water.</div><div>&nbsp;</div><div>The AFER project is part of Geoscience Australia’s Exploring for the Future (EFTF) Program—an eight year, $225 million Australian Government funded geoscience data and precompetitive information acquisition program to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, Geoscience Australia is building a national picture of Australia’s geology and resource potential. This will help support a strong economy, resilient society and sustainable environment for the benefit of all Australians. The EFTF program is supporting Australia’s transition to a low emissions economy, industry and agriculture sectors, as well as economic opportunities and social benefits for Australia’s regional and remote communities. Further details are available at http://www.ga.gov.au/eftf.This new data package consists of composite logs and supporting data which includes interpreted volume of clay/ shale, porosity, permeability and salinity.</div><div>&nbsp;</div><div>The data package includes the following datasets: </div><div>1)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Composite logs (PDF)</div><div>2)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Well logs (ASCII LAS)</div><div>3)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Well header information (Microsoft Excel™)[BB3]&nbsp;[MB4]&nbsp;</div><div>&nbsp;</div><div>These petrophysical interpretations are being used to support the AFER Project’s play-based energy resource assessments in the Pedirka and western Eromanga basins by building 3D geological models that include derived rock property maps.