2020
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A live linked-data API that expresses the AusPIX DGGS cells as a database of defined locations , describes the location attributes and maps the each cell onto a landing page . Their are billions of these cells so it is built as a virtual data-base where the AusPIX engine calculates information as required. Human readable and machine readable infrastructure.
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We present a resistivity model of the southern Tasmanides of southeastern Australia using Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) data. Modelled lower crustal conductivity anomalies resemble concentric geometries revealed in the upper crust by potential field and passive seismic data. These geometries are a key part of the crustal architecture predicted by the Lachlan Orocline model for the evolution of the southern Tasmanides, in which the Proterozoic Selwyn Block drives oroclinal rotation against the eastern Gondwana margin during the Silurian period. For the first time, we image these structures in three dimensions (3D) and show they persist below the Moho. These include a lower crustal conductor largely following the northern Selwyn Block margin. Spatial association between lower crustal conductors and both Paleozoic to Cenozoic mafic to intermediate alkaline volcanism and gold deposits suggests a genetic association i.e. fluid flow into the lower crust resulting in the deposition of conductive phases such as hydrogen, iron, sulphides and/or graphite. The 3D model resolves a different pattern of conductors in the lithospheric mantle, including northeast trending anomalies in the northern part of the model. Three of these conductors correspond to Cenozoic leucitite volcanoes along the Cosgrove mantle hotspot track which likely map the metasomatised mantle source region of these volcanoes. The northeasterly alignment of the conductors correlates with variations in the lithosphere-asthenosphere boundary (LAB) and the direction of Australian plate movement, and may be related to movement of an irregular LAB topography over the asthenosphere. By revealing the tectonic architecture of a Phanerozoic orogen and the overprint of more recent tectono-magmatic events, our resistivity model enhances our understanding of the lithospheric architecture and geodynamic processes in southeast Australia, demonstrating the ability of magnetotelluric data to image geological processes over time.
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Gold deposits form in a range of geodynamic settings and styles of deposition, associated with specific characteristics in fluid source and chemistry. These differences may lead to differences in the minerals that are deposited in the ascent pathway, and thus alter the physical properties that can be measured at different levels in the lithosphere. Models derived from magnetotelluric data are sensitive to lithospheric resistivity variations and have been increasingly applied to mineral exploration, with evidence emerging for a spatial association between many mineral deposits and lower crustal conductors. Southeastern Australia has estimated resource of ~5000 t gold contained within a variety of deposit styles. A resistivity model of this region was recently published from Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) data under a collaborative project between Geoscience Australia, the Geological Survey of New South Wales, and the Geological Survey of Victoria. This showed a strong spatial correlation between lower crustal conductors and gold deposits. In this presentation we examine the statistical and geological significance of this correlation for different deposit styles. We demonstrate that there are clear differences in the resistivity expression between different styles of gold deposition. The variability may reflect differences in the fluid source chemistry and geodynamic setting of the deposits, and will have important implications for the exploration of these resources.
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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 0.00021 degrees (approximately 22m) and shows uranium element concentration of the Yalgoo, WA, 2014 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2015 by the WA Government, and consisted of 126967 line-kilometres of data at a line spacing between 100m and 200m, and 50m 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. 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 GSSA Coompana Infill Doserate Grid Geodetic has a cell size of 0.00042 degrees (approximately 43m) and shows the terrestrial dose rate of the Coompana, SA, 2015. The data used to produce this grid was acquired in 2015 by the SA Government, and consisted of 286817 line-kilometres of data at a line spacing between 200m and 400m, and 80m 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 0.00042 degrees (approximately 43m) and shows thorium element concentration of the Coompana, SA, 2015 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2015 by the SA Government, and consisted of 286817 line-kilometres of data at a line spacing between 200m and 400m, and 80m 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 0.00042 degrees (approximately 43m) and shows potassium element concentration of the Coompana, SA, 2015 in units of percent (or %). The data used to produce this grid was acquired in 2015 by the SA Government, and consisted of 286817 line-kilometres of data at a line spacing between 200m and 400m, and 80m 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 0.00083 degrees (approximately 86m) and shows thorium element concentration of the Coompana, SA, 2015 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2015 by the SA Government, and consisted of 286817 line-kilometres of data at a line spacing between 200m and 400m, and 80m 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 GSSA Coompana TMI Grid Geodetic has a cell size of 0.00083 degrees (approximately 86m). The units are in nanoTesla (or nT). The data used to produce this grid was acquired in 2015 by the SA Government, and consisted of 286817 line-kilometres of data at a line spacing between 200m and 400m, and 80m 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 0.00042 degrees (approximately 43m) and shows uranium element concentration of the Coompana, SA, 2015 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2015 by the SA Government, and consisted of 286817 line-kilometres of data at a line spacing between 200m and 400m, and 80m terrain clearance.