Magnetotelluric (MT) measures the natural variations of the Earth's magnetic and electrical (telluric) fields. The Audio-Magnetotelluric method (AMT) samples signals in the frequency range of 10k Hz down to ~1Hz and provides information to the upper few kilometres of the crust. AMT data were collected at ten sites in the southern Thomson Orogen using Phoenix Geophysics equipment (MTU-5A, MTC-150L and PE5 electrodes). Instrument deployment periods were 7/Oct -29/Oct 2015 and 03/Aug-10/Aug 2016. Time series data were processed into frequency domain using remote reference and Robust Processing scheme. After quality assurance, processed data were exported to industry-standard EDI files. Time series data are available on request.

As part of the Australian Government's Onshore Energy Security Program (2006-2011) Geoscience Australia in collaboration with Geological Survey of Western Australia acquired magnetotelluric (MT) data along the deep crustal seismic reflection transect across the Yilgarn Craton, Officer Basin and Musgrave Province in Central Western Australia. The aim of the MT survey is to map the electrical resistivity distribution and improve scientific understanding of the crustal and upper mantle structure in this region. This information is complementary to that obtained from deep crustal seismic reflection, seismic refraction, potential field and geological data, which together provide new knowledge of the crustal architecture and geodynamics of the region. It is important for helping to determine the potential for both mineral and energy resources. Data are supplied as EDI files with support information.

Geoscience Australia in partnership with State and Territory Geological Surveys has applied the magnetotelluric (MT) technique to image Australia’s resistivity structure over the last decade. As part of the Mount Isa Geophysics Initiative program, MT data were collected at 138 sites along a 690 km transect in the South-Eastern Mount Isa. Geoscience Australia undertook data analysis and data inversion to create the most plausible resistivity model. 2D and 3D data modelling were undertaken using well-verified algorithms. The 2D and 3D resistivity models derived from the MT data show some consistent features that are likely to be the real subsurface geology. The near-surface conductive layer resolved by the MT models represents the Carpentaria and Eromanga sedimentary basins reasonably well, in terms of resistivity and thickness. The MT models reveal a predominant crustal-scale conductor, which is interpreted to be part of the Carpentaria Conductivity Anomaly. A number of localised zones of enhanced conductivity are also detected within the crust. These conductors correspond to known major faults identified by seismic and geological data. One of the faults, i.e. the Cork Fault, marks the tectonic boundary between the Mount Isa terrane and the Thomson Orogen. The geometries of these conductive bodies suggest that the enhanced conductivity may be caused by deformation or mineralisation associated with faulting. Some of these faults linking into the middle and lower crust are considered as the primary factors in the partitioning of mineralisation in the region. Results from the magnetotelluric data provide new insights into the understanding of the complex crustal structure where little geological history is known.

Magnetotelluric (MT) measures the natural variations of the Earth' magnetic and electrical (telluric) fields. The Audio-Magnetotelluric method (AMT) samples signal frequencies in the range of 20k Hz down to ~1Hz and provides data pertaining to the upper few kilometres of the Earth' crust. Broadband MT (BBMT) measures frequencies ranging from ~400 Hz down to periods of ~5000 s, providing measures of the conductivity of the crust. AMT and BBMT data were acquired at 138 stations with an interval of 2.5-5.0 km along a 690 km transect extending from Four Ways to Longreach in the South-eastern Mount Isa region. Full-waveform time series data were acquired and processed into frequency-domain transfer functions. Remote reference was applied to eliminate uncorrelated noise. After quality assurance, processed data were exported to industry-standard EDI files containing site info, impedance tensor, apparent resistivity, phase and vertical transfer function.

Magnetotelluric survey data acquired in association with the L190 Gawler-Officer-Musgrave-Amadeus Deep Crustal Seismic Survey. This survey was co-funded through AuScope, Primary Industry and Resources South Australia and Geoscience Australia's Onshore Energy Security Program. Data was acquired, processed and modelled by Geoscience Australia. The aim of the survey was to produce a two-dimensional image of electrical conductivity structure of the crust and upper mantle. This information is complementary to the reflection seismic and gravity data acquired along the 08GA-OM1 traverse. Data are supplied as EDI files with support information.

Magnetotelluric (MT) measures the natural variations of the Earth’ magnetic and electrical (telluric) fields. MT data were collected at forty-three sites in the Coompana region in Apr 2016 and Feb 2017. The instruments used were Phoenix Geophysics equipment including MTU-5A receiver, MTC-150L coils and PE5 electrodes. Time series data were processed into frequency domain using remote reference and Robust Processing scheme. After quality assurance, processed data were exported to industry-standard EDI files. Time series data are available on request from clientservices@ga.gov.au.

Magnetotelluric survey data acquired in association with the L189 Gawler-Curnamona-Arrowie Deep Crustal Seismic Survey over the Curnamona Province. This survey was funded through the Onshore Energy Security Program. Data was acquired by Quantec Geoscience. Analysis and modelling was undertaken by Geoscience Australia . The aim of the survey was to produce a two-dimensional image of electrical conductivity structure of the crust and upper mantle over the Curnamona Province. This information is complementary to the reflection seismic and gravity data acquired along the 08GA-C1 traverse. Data are supplied as EDI files with support information.

Magnetotelluric survey data acquired in association with the L192 Georgina-Arunta Deep Crustal Seismic Survey. This survey was funded through the Onshore Energy Security Program using the Auscope equipment from the ANSIR pool. The aim of the survey was to produce a two-dimensional image of electrical conductivity structure of the crust and upper mantle over the western Georgina Basin and the Arunta region of the Northern Territory. This information is complementary to the reflection seismic and gravity data acquired along the 09GA-GA1 traverse. Data are supplied as EDI files with support information.

The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) aims to collect long period magnetotelluric data on a half degree grid across the Australian continent. Data were collected in northern Australia under Geoscience Australia’s Exploring for the Future (EFTF) program from 2016 to 2019. This survey covers the area in south parts of Northern Territory and north western region of Queensland. The project aims to improve understanding of the lithospheric structure in northern Australia. It also provide pre-competitive data and knowledge for selecting mineral prospective areas in the under-explored and covered regions. This data package contains the preferred resistivity model and associated information for the project. The report provides details for data acquisition, data process and data inversion. The results provide new insights on the lithospheric architecture and mineral potential in the region.

Geoscience Australia (GA) and the Geological Survey of Queensland (GSQ) conducted the Cloncurry Magnetotelluric (MT) survey. MT data (0.001 s to 1000 s in period) at 476 sites with a grid spacing of 2km were acquired over an approximate 40km x 60km area in the Cloncurry region from July to November 2016. The survey area covers the eastern margin of the Mount Isa Block situated to the west of the Eromanga Basin. The MT data can image the thickness of cover, the basement architecture and the crustal architecture in this area that has high resource exploration potential. Data QA/QC were performed during the data acquisition stage of the survey. This release includes processed MT data and a data acquisiton report written by the contractor. Details on the data processing, data analysis, and modelling/inversion of the data will be released as a comprehensive report at a later date.