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.

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)

Legacy product - no abstract available

The first large scale projects for geological storage of carbon dioxide on the Australian mainland are likely to occur within sedimentary sequences that underlie or are within the Triassic Cretaceous Great Artesian Basin aquifer sequence. Recent national and state assessments have concluded that certain deep formations within the Great Artesian Basin show considerable geological suitability for the storage of greenhouse gases. These same formations contain trapped methane and naturally generated carbon dioxide stored for millions of years. In July 2010, the Queensland Government released exploration permits for Greenhouse Gas Storage in the Surat and Galilee basins. An important consideration in assessing the potential economic, environmental, health and safety risks of such projects is the potential impact carbon dioxide migrating out of storage reservoirs could have on overlying groundwater resources. The risk and impact of carbon dioxide migrating from a greenhouse gas storage reservoir into groundwater cannot be objectively assessed without an adequate knowledge of the natural baseline characteristics of the groundwater within these systems. Due to the phase behaviour of carbon dioxide, geological storage of carbon dioxide in the supercritical state requires depths greater than 800m, but there are few hydrogeochemical studies of these deeper aquifers in the prospective storage areas. Historical hydrogeochemical data were compiled from various State and Federal Government agencies. In addition, hydrogeochemical information has been compiled from thousands of petroleum well completion reports in order to obtain more information on the deeper aquifers, not typically used for agriculture or human consumption. The data were passed through a quality checking procedure to check for mud contamination and ascertain whether a representative sample had been collected. The large majority of the samples proved to be contaminated but a small selection passed the quality checking criteria.

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.

No abstract available

No abstract available