<div> A key issue for explorers in Australia is the abundant sedimentary and regolith cover obscuring access to underlying potentially prospective rocks. &nbsp;Multilayered chronostratigraphic interpretation of regional broad line-spaced (~20&nbsp;km) airborne electromagnetic (AEM) conductivity sections have led to breakthroughs in Australia’s near-surface geoscience. &nbsp;A dedicated/systematic workflow has been developed to characterise the thickness of cover and the depth to basement rocks, by delineating contact geometries, and by capturing stratigraphic units, their ages and relationships. &nbsp;Results provide a fundamental geological framework, currently covering 27% of the Australian continent, or approximately 2,085,000&nbsp;km2. &nbsp;Delivery as precompetitive data in various non-proprietary formats and on various platforms ensures that these interpretations represent an enduring and meaningful contribution to academia, government and industry.&nbsp;The outputs support resource exploration, hazard mapping, environmental management, and uncertainty attribution.&nbsp;This work encourages exploration investment, can reduce exploration risks and costs, helps expand search area whilst aiding target identification, and allows users to make well-informed decisions. Presented herein are some key findings from interpretations in potentially prospective, yet in some cases, underexplored regions from around Australia.&nbsp;</div> This abstract was submitted & presented to the 8th International Airborne Electromagnetics Workshop (AEM2023) (https://www.aseg.org.au/news/aem-2023)

<div>The Australian Sub-bottom Profiling Guidelines were developed by the AusSeabed community to establish a standardised approach to the acquisition of sub-bottom profiler data in an Australian context. They complement a suite of ocean best practice guidelines developed by the AusSeabed community including the <a href="https://pid.geoscience.gov.au/dataset/ga/121571">Australian Multibeam Guidelines</a> (eCat Record 121571) and the Australian <a href="https://repository.oceanbestpractices.org/handle/11329/2080">Satellite Derived Bathymetry Guidelines</a>.</div><div>The guidelines provide recommended procedures for data acquisition, quality checking and data submission to the AusSeabed marine data portal. They were initially designed for use by the Australian Hydrographic Office Hydroscheme Industry Partnership Program (HIPP) to enable the acquisition of standardised, efficient and effective sub-bottom profile data for general seabed characterisation and collection of baseline data. Additionally, the guidelines may be used by any agency or party collecting seabed geophysical data in Australia’s marine jurisdiction for a range of use cases. </div><div><br></div><div>The guidelines include a broad examination of data acquisition, basic processing for quality checking, metadata description, and guidance for data submission to AusSeabed. They do not include prescriptive equipment-specific hardware and software specifications, detailed user-defined settings or instrument preparation activities such as bench/workshop tests, personnel requirements, or provide survey costing information.</div><div><br></div>

<div>The Magnetotelluric (MT) Sites database contains the location of sites where magnetotelluric (MT) data have been acquired by surveys. These surveys have been undertaken by Geoscience Australia and its predecessor organisations and collaborative partners including, but not limited to, the Geological Survey of New South Wales, the Northern Territory Geological Survey, the Geological Survey of Queensland, the Geological Survey of South Australia, Mineral Resources Tasmania, the Geological Survey of Victoria and the Geological Survey of Western Australia and their parent government departments, AuScope, the University of Adelaide, Curtin University and University of Tasmania. Database development was completed as part of Exploring for the Future (EFTF) and the database will utilised for ongoing storage of site information from future MT acquisition projects beyond EFTF. Location, elevation, data acquisition date and instrument information are provided with each site. The MT Sites database is a subset of tables within the larger Geophysical Surveys and Datasets Database. </div><div><br></div><div>The resource is accessible via the Geoscience Australia Portal&nbsp;(https://portal.ga.gov.au/), use Magnetotelluric as your search term to find the relevant data.</div>

<div>Mount Isa Province in northern Australia is one of the world's most strongly endowed regions for base metals and host to major iron-oxide-copper-gold (IOCG) deposits. The Carpentaria Conductivity Anomaly at the eastern margin of the Province is a major electrical conductivity structure of the Australian continent. We have used magnetotelluric and deep seismic reflection data to image the crustal architecture in this complex region to understand the crustal-scale fluid pathways and potential mineral occurrences. The resistivity models reveal a number of prominent crustal-scale conductors, suggesting that the Carpentaria Conductivity Anomaly is likely caused by a series of isolated or interconnected bodies. These conductors characterise the position and geometry of the ancient Gidyea Suture Zone, interpreted as a west-dipping subduction zone. The conductivity anomaly may record the activity of fluid hydration involved during a subduction event, with the enhanced conductivity likely being caused by deformation or mineralisation of graphitic or sulfidic rocks during orogensis. The distribution of known gold and copper deposits shows a close spatial correlation with the suture zone, suggesting that this structure is potentially a fundamental control on IOCG deposits in its vicinity. The interpretation of the seismic image shows a good correlation with the resistivity models. The implication is that crustal-penetrating structures act as potential pathways for fluid movement to form mineral deposits in the upper crust. The significance of mapping such structures using geophysics is highlighted for mineral exploration.</div><div><br></div>This Abstract was submitted/presented to the 2022 Sub 22 Conference 28-30 November (http://sub22.w.tas.currinda.com/)

<div>This document defines the technical standards set by Geoscience Australia for the acquisition, processing and supply of airborne magnetic, horizontal magnetic gradient and radiometric (gamma-ray spectrometric) data. The technical standards cover the requirements for equipment, calibrations, quality control checks, reporting and data formats for airborne surveys.</div><div><br></div><div><br></div><div><strong>Table of Contents</strong></div><div><br></div><div>Attachment 1A – Data Acquisition and Processing</div><div><br></div><div>1 Aircraft</div><div>2 Flight and Tie Lines</div><div>3 Global Navigation Satellite System (GNSS)</div><div>4 Parallax Correction</div><div>5 Altimeter</div><div>6 Barometer</div><div>7 Digital Elevation Model</div><div>8 Magnetic System Equipment</div><div>9 Magnetic Gradient System Equipment</div><div>10 Magnetic / Gradient Calibration and Quality Tolerances</div><div>11 Magnetic Base Station (Diurnal Monitoring)</div><div>12 Magnetic Data Reduction</div><div>13 Magnetic Gradient Data Reduction</div><div>14 Radiometric System Equipment</div><div>15 Radiometric Calibration and Quality Tolerances</div><div>16 Radiometric Data Reduction</div><div><br></div><div>Attachment 1B – Reporting and Data Supply</div><div><br></div><div>1 General</div><div>2 Calibration Report</div><div>3 Daily Acquisition Report</div><div>4 Weekly Acquisition Report</div><div>5 Operations and Processing Summary Report</div><div>6 Supply Schedule</div><div><br></div><div>Attachment 1C – Data Formats</div><div><br></div><div>1 General</div><div>2 Point-Located Data Files</div><div>3 Definition Files</div><div>4 Description Files</div><div>5 Raw-Edited Magnetic Data File</div><div>6 Reduced Magnetic Data File</div><div>7 Diurnal Magnetic Data File</div><div>8 Raw-Edited Magnetic Gradient Data File</div><div>9 Reduced Magnetic Gradiometry Data File</div><div>10 Raw-Edited Radiometric Data File</div><div>11 Reduced Radiometric Data File</div><div>12 Gridded Data Files</div><div>13 Image Enhanced GeoTIFF Files

<div>Near-surface magnetizations are ubiquitous across many areas of Australia and complicate reliable estimation of depth to deeper magnetizations. We have selected four test areas in which we use equivalent source dipoles to represent and quantify the near-surface magnetizations. We present a synthetic modelling study that demonstrates that field variations from the near-surface magnetizations substantially degrade estimation of depth to a magnetization 500 metres below the modelled sensor elevation and that these problems persist even for anomalies with significantly higher amplitudes. However, preferential attenuation of the fields from near surface magnetizations by upward continuation proved quite effective in improving estimation of depth to those magnetizations.</div> This Abstract was submitted/presented at the 2023 Australasian Exploration Geoscience Conference (AEGC) 13-18 March (https://2023.aegc.com.au/)

<div>The active seismic and passive seismic database contains metadata about Australian land seismic surveys acquired by Geoscience Australia and its collaborative partners. </div><div>For active seismic this is onshore surveys with metadata including survey header data, line location and positional information, and the energy source type and parameters used to acquire the seismic line data. For passive seismic this metadata includes information about station name and location, start and end dates, operators and instruments. Each also contains a field that contains links to the published data. </div><div><br></div><div>The active and passive seismic database is a subset of tables within the larger Geophysical Surveys and Datasets Database and development of these databases was completed as part of the second phase of the Exploring for the Future (EFTF) program (2020-2024). The resource is accessible via the Geoscience Australia Portal&nbsp;(https://portal.ga.gov.au/), under 'Geophysics'. Use 'active seismic' or 'passive seismic' as search terms. </div><div><br></div>