AusLAMP is a collaborative national project to cover Australia with long-period magnetotelluric (MT) data in an approximately 55 km spaced array. Signatures from past tectonothermal events can be retained in the lithosphere for hundreds of millions of years when these events deposit conductive mineralogy that is imaged by MT as electrically conductive pathways. MT also images regions of different bulk conductivity and can help to understand the continuation of crustal domains down into the mantle, and address questions on the tectonic evolution of Australia. The AusLAMP data presented here were collected as part of three separate collaborative projects involving several organisations. Geoscience Australia (GA), the Geological Survey of South Australia, the Geological Survey of New South Wales, the Geological Survey of Victoria, and the University of Adelaide all contributed staff and/or funding to collection of AusLAMP data; GA and AuScope contributed instrumentation. The data cover the Paleo-Mesoproterozoic Curnamona Province, the Neoproterozoic Flinders Ranges, and the Cambrian Delamerian Orogen, encompassing eastern South Australia and western New South Wales and western Victoria. This project represents the first electrical resistivity model to image the entire Curnamona Province and most of the onshore extent of the Delamerian Orogen, crossing the geographical state borders between South Australia, New South Wales and Victoria.

The MTPy Python library is open source software that aims to facilitate processing, analysis, modelling, and inversion of magnetotelluric (MT) data. Until recently, MTpy has contained bugs and gaps in both functionality and documentation, which have limited its use to date. We are developing MTPy to rectify these problems and expand functionality. Key improvements include adding new functions and classes to the modules that handle ModEM inputs and outputs, improving data and model visualization tools, refactoring the code to improve maintainability, quality, and consistency, and developing documentation.

Several narrow, linear, highly electrically conductive zones in the crust have been detected across Australia by geomagnetic deep sounding and magnetotelluric measurements made during the previous 50 years. Three major such conductivity anomalies collectively span Australia from north to south; the Carpentaria anomaly in Queensland and the Flinders and Eyre Peninsula anomalies in South Australia. They do not appear to be electrically connected at present; whether they are related in origin is a subject of further research. Recently, new magnetotelluric data have been acquired across or near to all three zones along deep seismic reflection transects which were designed to investigate crustal architecture and mineral and energy potential. Results from the seismic and MT surveys across the Carpentaria Anomaly suggest that the data are imaging a west-dipping suture forming the eastern margin of the Mount Isa province. The suture is interpreted to be the consequence of subduction and accretion prior to 1850 Ma. The Flinders Anomaly extends in an arcuate belt to the east of Lake Frome in the Curnamona Province to transect the Willyama Supergroup and the southern Flinders Ranges in a south-westerly direction, following structural trends. New magnetotelluric data acquired along two seismic transects has further refined the position and depth of the conductive zone.

As global metal demands are increasing whilst new discoveries are declining, the magnetotelluric (MT) technique has shown promise as an effective technique to aid mineral systems mapping. Several case studies have shown a spatial correlation between mineral deposits and conductors, with some showing that resistivity models derived from MT are capable of mapping mineral systems from the lithosphere to deposit scale. However, until now, the statistical significance of such correlations has not been demonstrated and therefore hindered robust utilization of MT data in mineral potential assessments. Here we quantitatively analyze resistivity models from Australia, the United States of America (USA), South America and China and demonstrate that there is a statistically-significant correlation between upper mantle conductors and porphyry copper deposits, and between mid-crustal conductors and orogenic gold deposits. Volcanic hosted massive sulfide deposits show significant correlation with upper mantle conductors in Australia. Differences in the correlation pattern between these deposit types likely relate to differences in the chemistry, redox state and location of source mineralizing fluids and magmas, and indicate signatures of mineral system processes can be preserved in the crust and mantle lithosphere for hundreds of millions of years. Appeared in Scientific Reports volume 12, Article number: 8190 (2022), 17 May 2022

This collection includes calibrated time-series data and other products from Geoscience Australia's geomagnetic observatory network in Australia and Antarctica. Data dates back to 1924. <b>Value: </b>These data are used in mathematical models of the geomagnetic field, in resource exploration and exploitation, to monitor space weather, and for scientific research. The resulting information can be used for compass-based navigation, magnetic direction finding, and to help protect communities by mitigating the potential hazards generated by magnetic storms. <b>Scope: </b>Continuous geomagnetic time series data, indices of magnetic activity and associated metadata, Data dates back to 1924.

Magnetotelluric survey data acquired in association with the L184 Isa-Georgetown Deep Crustal Seismic Survey and L185 Charters Towers Deep Crustal Seismic Survey. These surveys were funded through the Geoscience Australia's Onshore Energy Security Program and the Queensland Governments Smart Mining - Future Prosperity Program. Quantec Geoscience were contracted to acquire and process these data. The aim of the surveys was to produce a two-dimensional image of electrical conductivity structure of the crust and upper mantle over the Isa and Georgetown blocks. This information is complementary to the reflection seismic and gravity data acquired along lines 07GA-IG1, 07GA-IG2 and 07GA-GC1. Data are supplied as EDI files with support information and models.

Magnetotelluric survey data acquired in association with the L189 Gawler-Curnamona-Arrowie Deep Crustal Seismic Survey over the Gawler Craton. This survey was a collaborative project with the University of Adelaide and was funded through the Onshore Energy Security Program. The aim of the survey was to produce a two-dimensional image of electrical conductivity structure of the crust and upper mantle over the Gawler Craton. This information is complementary to the reflection seismic and gravity data acquired along the 08GA-G1 traverse. Data are supplied as EDI files with support information.

The magnetotelluric (MT) data were acquired along a total of 690 km of the Youanmi deep seismic reflection traverses 10GA-YU1, 10GA-YU2 and 10GA-YU3-in Western Australia. This was a collaborative project between Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA), which provided the funding. The aim of the MT survey was to produce information of the electrical conductivity structure of the crust and upper mantle. This information is complementary to that obtained from deep seismic reflection, gravity, magnetic and geological data, which together provide new knowledge of the crustal architecture, rock properties and geodynamics of the region, important for helping to determine the potential for both mineral and energy resources. Data are supplied as EDI files with support information.

Magnetotelluric (MT) measures the natural variations of the Earth’ magnetic and electrical (telluric) fields. In 2018, MT data including broadband and audio-magnetotelluric data were collected across the Olympic Domain in South Australia. MT data at 327 sites with spacings from ~1.5km to ~10km were collected by contractor Zonge Engineering and Research Organisation Australia, on behalf of Geological Survey of South Australia and Geoscience Australia. The survey was funded by the Geological Survey of South Australia's PaceCopper Initiative. Six extra MT stations (MASLIN1-6) were collected and funded by Investigator Resources Ltd. They were provided by Geological Survey of South Australia. This data package contains 333 processed edi files across the Olympic Domain in South Australia.

The Coompana Project is a collaborative project between Geoscience Australia (GA) and the Geological Survey of South Australia (GSSA), which aims to provide new precompetitive geological, geophysical and geochemical data in the under-explored Coompana Province in South Australia. The pre-drilling geophysics program was undertaken to assist the drilling process by reducing the uncertainty associated with intersecting the targeted stratigraphy. Firstly, the magnetotellurics (MT) technique was tested at six sites where previous drill holes were located to benchmark the application of MT method with respect to estimating cover thickness in the region. Comparison with drill-hole details indicates that the method is capable of identifying major stratigraphic structures and providing cover thickness estimates with a reasonable accuracy (within 10%). Subsequently, MT data were acquired at eight proposed drilling sites in February 2017. 1D and 2D data modelling were undertaken using different algorithms to improve confidence level. Finally, estimates of the cover thickness with specified uncertainty at proposed drilling sites are produced. This report presents MT data acquisition and processing, data inversion and preliminary interpretation of model results. Limitations and uncertainty associated with the MT technique is discussed.