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  • Compilation of new and existing data can be used to show systematic variations in initial ore-related Pb isotope ratios and derived parameters for the Lachlan and Delamerian orogens of southeast Australia. In addition to mapping tectonic boundaries and providing genetic context to mineralising processes, these variations map mineralised provinces at the orogenic scale and can provide vectors to ore at the district scale. In New South Wales and Victoria, mapping using a parameter termed the 'Lachlan Lead Index' (LLI), which measures relative mixing between crustal- and mantle-derived Pb using the curves of Carr et al. (1995, Economic Geology 90:14671505), clearly demarcates the boundary between the Eastern and Central Lachlan provinces, and seems to identify boundaries between zones within the Western Lachlan Province of Victoria. The LLI also maps the extent of the isotopically juvenile Macquarie 'Arc' in New South Wales. However, rocks in the Rockley-Gulgong Belt, initially mapped as part of the Macquarie Arc, have a more evolved isotopic character, suggesting that these rocks are not part of the Macquarie Arc. This interpretation supports recent mapping that casts doubt on the attribution of this belt to the Macquarie Arc (Quinn, et al., 2014, Journal of the Geological Society of London 171:723736). The LLI has also identified small exposures of Ordovician volcanic rocks, well removed from the main Macquarie Arc, as possible correlates to this arc, with potential to host porphyry and epithermal deposits. Metallogenically, porphyry Cu-Au deposits in the Macquarie Arc are characterised by juvenile Pb. In contrast, Sn and Mo deposits in the Central Lachlan Province (i.e., the Wagga tin belt) are characterised by highly evolved Pb even though these deposits formed over 30 million years. Moreover, the Pb isotope data suggest that the original interpretation that copper deposits in the Girilambone district are volcanic-associated massive sulfide deposits was correct and that these deposits formed in a back-arc to the Macquarie Arc at ~480 Ma. In the Mount Read Volcanics of western Tasmania, all deposits appear to cluster along the same growth curve. However, when divided according to age (i.e., Cambrian (~500 Ma) versus Devonian (~360 Ma)), spatial patterns are visible in 206Pb/204Pb data. For Cambrian deposits 206Pb/204Pb decreases overall to the southeast, although low values are also present in the far south (i.e., Elliott Bay) and northeast. The most highly mineralised central part of the belt seems to be broadly associated with the zone of highest 206Pb/204Pb. Variations in 206Pb/204Pb for Devonian deposits broadly mimic the patterns seen for the Cambrian deposits. More importantly, a district-scale pattern in 206Pb/204Pb is present in the Zeehan district. Isotopically, the Sn-dominated core of the Zeehan district (e.g. Queen Hill and Severn deposits) is characterised by high 206Pb/204Pb, which decreases outward into the Zn-Pb-Ag-dominated peripheries. Lead isotope distribution patterns can potentially be used as an ore vector in this and other intrusion-centered mineral systems.

  • The data covers an area of approximately 4000 sq km in the Namoi Valley, located around Narrabri, NSW. The LiDAR was captured by RPS Spatial in September and October 2013 with a point density of two points per square metre. The specified accuracies; 30cm vertical and 80cm horizontal, were achieved and verified through a rigorous network of check points and base stations. A set of seamless products were produced including hydro-flattened bare earth DEMs, DSMs, Canopy Height Models (CHM) and Foliage Cover Models (FCM). The outputs of the project are compliant with National ICSM LiDAR Product Specifications and the NEDF.

  • Skylab spacecraft stereoscopic photography of the Alice Springs and Snowy Mountains regions of Australia was studied by conventional photogeological techniques to assess its usefulness in geological mapping. In the arid Alice Springs region, which has well exposed sedimentary rocks and relatively simple structures, broad rock units can be differentiated and correlated, and rock trends, joints and folds interpreted with the same accuracy as that shown on the 1:500 000 scale geological map of the region. The distribution of Cainozoic travertine and other surficial materials can be interpreted with sufficient reliability to allow updating of 1:250 000 scale geological maps. In the more humid Snowy Mountains region, where the geology-to-morphology relationships are complex and varied, little lithological information can be obtained: only Tertiary volcanic rocks and alluvium can be identified and outlined with confidence. The Skylab photographs proved more useful for structural interpretations: faults, lineaments and joint trends can be detected. Several circular structures can be related to features of igneous origin. Statistical analysis of linear features revealed a direct relationship between known structural trends and linear features annotated on low resolution Skylab photographs.

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    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. The terrestrial dose rate grid is derived as a linear combination of the filtered K, U and Th grids. A low pass filter is applied to this grid to generate the filtered terrestrial dose rate grid. This GSNSW Southeast Lachlan Doserate Grid Geodetic has a cell size of 0.0005 degrees (approximately 50m) and shows the terrestrial dose rate of the Southeast Lachlan, NSW, 2010. The data used to produce this grid was acquired in 2010 by the NSW Government, and consisted of 108251 line-kilometres of data at a line spacing between 250m and 500m, and 60m terrain clearance.

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    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This radiometric potassium grid has a cell size of 0.0005 degrees (approximately 50m) and shows potassium element concentration of the Southeast Lachlan, NSW, 2010 in units of percent (or %). The data used to produce this grid was acquired in 2010 by the NSW Government, and consisted of 108251 line-kilometres of data at a line spacing between 250m and 500m, and 60m terrain clearance.

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    Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This GSNSW Southeast Lachlan TMI Grid Geodetic has a cell size of 0.0005 degrees (approximately 50m). The units are in nanoTesla (or nT). The data used to produce this grid was acquired in 2010 by the NSW Government, and consisted of 108251 line-kilometres of data at a line spacing between 250m and 500m, and 60m terrain clearance.

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    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Southeast Lachlan, NSW, 2010 (P1218), radiometric line data, AWAGS levelled were acquired in 2010 by the NSW Government, and consisted of 108251 line-kilometres of data at a line spacing between 250m and 500m, and 60m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.

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    Digital Elevation data record the terrain height variations from the processed point- or line-located data recorded during a geophysical survey. This NSW Coonabarabran elevation laser grid is elevation data for the Coonabarabran Airborne Magnetic Radiometric and DEM Survey, NSW, 2017. This survey was acquired under the project No. 1290 for the geological survey of NSW. The grid has a cell size of 0.00045 degrees (approximately 47m). This grid contains the ground elevation relative to the geoid for the Coonabarabran Airborne Magnetic Radiometric and DEM Survey, NSW, 2017. It represents the vertical distance from a location on the Earth's surface to the geoid. The data are given in units of meters. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose.

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    Digital Elevation data record the terrain height variations from the processed point- or line-located data recorded during a geophysical survey. This NSW Coonabarabran elevation radar grid is elevation data for the Coonabarabran Airborne Magnetic Radiometric and DEM Survey, NSW, 2017. This survey was acquired under the project No. 1290 for the geological survey of NSW. The grid has a cell size of 0.00045 degrees (approximately 47m). This grid contains the ground elevation relative to the geoid for the Coonabarabran Airborne Magnetic Radiometric and DEM Survey, NSW, 2017. It represents the vertical distance from a location on the Earth's surface to the geoid. The data are given in units of meters. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose.

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    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This radiometric potassium grid has a cell size of 0.00045 degrees (approximately 47m) and shows potassium element concentration of the Coonabarabran Airborne Magnetic Radiometric and DEM Survey, NSW, 2017 in units of percent (or %). The data used to produce this grid was acquired in 2017 by the NSW Government, and consisted of 50961 line-kilometres of data at 250m line spacing and 60m terrain clearance.