2022
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Exploring for the Future (EFTF) is an ongoing multiyear initiative by the Australian Government, conducted by Geoscience Australia, in partnership with state and Northern Territory government agencies and other partner research institutes. The first phase of the EFTF program (2016-2020) aimed to improve Australia’s desirability for industry investment in resource exploration in frontier or ‘greenfield’ regions across northern Australia. As part of the program, Geoscience Australia employed a range of both established and innovative techniques to gather new precompetitive data and information to develop new insight into the energy, mineral and groundwater resource potential across northern Australia. To maximise impact and to stimulate industry exploration activity, Geoscience Australia focussed activities in greenfield areas where understanding of resource potential was limited. In order to address this overarching objective under the EFTF program, Geoscience Australia led acquisition of two deep crustal reflection seismic surveys in the South Nicholson region, an understudied area of little previous seismic data, straddling north-eastern Northern Territory and north-western Queensland. The first survey, L210 South Nicholson 2D Deep Crustal Seismic Survey acquired in 2017, consisted of five overlapping seismic lines (17GA-SN1 to SN5), totalling ~1100 line-km. Survey L210 linked directly into legacy Geoscience Australia seismic lines (06GA-M1 and 06GA-M2) in the vicinity of the world-class Pb-Zn Century Mine in Queensland. The results from survey L210 profoundly revised our geological understanding of the South Nicholson region, and led to the key discovery of an extensive sag basin, the Carrara Sub-basin, containing highly prospective late Paleoproterozoic to Mesoproterozoic rocks with strong affinities with the adjacent Mount Isa Province and Lawn Hill Platform. To complement and expand on the outstanding success of the South Nicholson survey and to continue to explore the resource potential across the underexplored and mostly undercover South Nicholson and Barkly regions, a second seismic survey was acquired in late 2019, the Barkly 2D reflection survey (L212). The Barkly seismic survey comprises five intersecting lines (19GA-B1 to B5), totalling ~813 line-km, extending from the NT-QLD border in the south-east, near Camooweal, to the highly prospective Beetaloo Sub-basin in the north-west. The survey ties into the South Nicholson survey (L210), the recently acquired Camooweal 2D reflection seismic survey by the Geological Survey of Queensland and industry 2D seismic in the Beetaloo Sub-basin, leveraging on and maximising the scientific value and impact on all surveys. The Barkly reflection seismic data images the south-western margin of the Carrara Sub-basin and identified additional previously unrecognised, structurally-disrupted basins of Proterozoic strata, bounded by broadly northeast trending basement highs. Critically, the survey demonstrates the stratigraphic continuity of highly prospective Proterozoic strata from the Beetaloo Sub-basin into these newly discovered, but as yet unevaluated, concealed basins and into the Carrara Sub-basin, further attesting to the regions outstanding potential for mineral and hydrocarbon resources. This survey, in concert with the South Nicholson seismic survey and other complementary EFTF funded regional geochemical, geochronology and geophysical data acquisition surveys, significantly improves our understanding of the geological evolution, basin architecture and the resource potential of this previously sparsely studied region.
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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 Cobar P5009 EXT 1 total magnetic grid has a cell size of 0.00039074 degrees (approximately 40m). The units are in nanoTesla (or nT). The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing and 60m terrain clearance.
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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 Cobar P5009 EXT 1 digital elevation model radar grid is elevation data for the Cobar Magnetic and Radiometric Survey, 2021. This survey was acquired under the project No. 5009 for the geological survey of NSW. The grid has a cell size of 0.00039074 degrees (approximately 40m). This grid contains the ground elevation relative to the geoid for the Cobar Magnetic and Radiometric Survey, 2021. 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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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 Cobar P5009 EXT 3 reduced to pole fft 1st vertical derivative grid is the first vertical derivative of the TMI RTP grid of the Cobar Magnetic and Radiometric Survey, 2021 survey. This grid has a cell size of 0.00039074 degrees (approximately 40m) , and given in units of nT per metre (nT/m). The data used to produce the TMI grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing and 60m terrain clearance. The data has had a variable reduction to the pole applied to centre the magnetic anomaly over the magnetised body. The VRTP processing followed a differential reduction to pole calculation up to 5th order polynomial. Magnetic inclination and declination were derived from the IGRF-11 geomagnetic reference model using a data representative date and elevation representative of the survey. A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the TMI RTP grid of the Cobar Magnetic and Radiometric Survey, 2021 survey to produce this grid. This grid was calculated using an algorithm from the INTREPID Geophysics software package. This grid shows the magnetic response of subsurface features with contrasting magnetic susceptibilities. The grid can also be used to locate structural features such as dykes.
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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 magnetic grid has a cell size of 0.00039074 degrees (approximately 40m).The data are in nanoTesla (or nT). The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing and 60m terrain clearance. The data has had a variable reduction to the pole applied to centre the magnetic anomaly over the magnetised body. The VRTP processing followed a differential reduction to pole calculation up to 5th order polynomial. Magnetic inclination and declination were derived from the IGRF-11 geomagnetic reference model using a data representative date and elevation representative of the survey.
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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 Cobar P5009 Main dose rate grid has a cell size of 0.00039074 degrees (approximately 40m) and shows the terrestrial dose rate of the Cobar Magnetic and Radiometric Survey, 2021. The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing 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 0.00039074 degrees (approximately 40m) and shows potassium element concentration of the Cobar Magnetic and Radiometric Survey, 2021 in units of percent (or %). The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing 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 thorium grid has a cell size of 0.00039074 degrees (approximately 40m) and shows thorium element concentration of the Cobar Magnetic and Radiometric Survey, 2021 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing 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 uranium grid has a cell size of 0.00039074 degrees (approximately 40m) and shows uranium element concentration of the Cobar Magnetic and Radiometric Survey, 2021 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing 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 magnetic grid has a cell size of 0.00039074 degrees (approximately 40m).The data are in nanoTesla (or nT). The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing and 60m terrain clearance. The data has had a variable reduction to the pole applied to centre the magnetic anomaly over the magnetised body. The VRTP processing followed a differential reduction to pole calculation up to 5th order polynomial. Magnetic inclination and declination were derived from the IGRF-11 geomagnetic reference model using a data representative date and elevation representative of the survey.