This OGC compliant service provides access to magnetotelluric data and associated products, which have been produced by Geoscience Australia’s Magnetotelluric Program. This program includes regional magnetotelluric projects and the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP), a collaborative project between Geoscience Australia, the State and Northern Territory geological surveys, universities, and other research organisations. The data provided in this service comprise resistivity model depth sections and the locations of sites used in these studies.

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

Geoscience Australia (GA), in partnership with State (SA, NSW, VIC, QLD, WA and TAS) and Northern Territory Geological Surveys, has applied the magnetotelluric (MT) technique to image the resistivity structure of the Australian continent over the last decade. Data have been acquired at nearly 5000 stations across Australia through a national MT survey program and regional MT surveys. Most of the data are available at GA’s website. These data provided valuable information for multi-disciplinary interpretations that incorporate various datasets. This release package includes ArcGIS shape files and Excel files of MT station locations for the completed AusLAMP and regional surveys up to December 2017.

<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>

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.

The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP): New South Wales (NSW) magnetotelluric survey is a collaborative project between the Geological Survey of New South Wales (GSNSW) and Geoscience Australia. Long period magnetotelluric data are being acquired at around 305 sites on a half degree grid spacing across the state of NSW. <u>Phase one</u> This record outlines the field acquisition, data QA/QC, and data processing methodologies relating to the 224 sites released in phase one. The data are released in EDI format containing impedance estimates and transfer functions for each processed site. <u>Phase two</u> A further 73 EDI format data are released as part of phase two. These data were collected and processed using the same methodology as described in the GA record released as part of phase one.

The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) aims to collect long period magnetotelluric data on a half degree (~55 km) grid across the Australian continent. New datasets have been collected in Northern Australia, as part of Geoscience Australia’s Exploring for the Future (EFTF) program with in-kind contributions from the Northern Territory Geological Survey and the Geological Survey of Queensland. This web service depicts the location of the 155 sites which were used in this study.

<p>The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) aims to collect long period magnetotelluric data on a half degree (~55 km) grid across the Australian continent. New datasets have been collected in Northern Australia, as part of Geoscience Australia’s Exploring for the Future (EFTF) program with in-kind contributions from the Northern Territory Geological Survey and the Queensland Geological Survey. <p>This release includes preliminary AusLAMP models in an under-explored region between Tennant Creek in the Northern Territory and Cloncurry in Queensland. Long period magnetotelluric data from 155 sites were used in this model. Magnetotelluric data acquisition in this region continues. The preliminary model results provide new insights to the lithospheric architecture and mineralisation in the region. There is a connection between conductive anomalies, large-scale lithospheric boundaries and the distribution of mineral deposits.

The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) aims to collect long period magnetotelluric data on a half degree (~55 km) grid across the Australian continent. New datasets have been collected in Northern Australia, as part of Geoscience Australia’s Exploring for the Future (EFTF) program with in-kind contributions from the Northern Territory Geological Survey and the Geological Survey of Queensland. This web service depicts the location of the 155 sites which were used in this study.

Long-period magnetotelluric (MT) data allow geoscientists to investigate the link between mineralisation and lithospheric-scale features and processes. In particular, the highly conductive structures imaged by MT data appear to map the pathways of large-scale palaeo-fluid migration, the identification of which is an important element of several mineral system models. Given the importance of these data, governments and academia have united under the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) to collect long-period MT data across the continent on a ~55 km-spaced grid. Here, we use AusLAMP data to demonstrate the MT method as a regional-scale tool to identify and select prospective areas for mineral exploration undercover. We focus on the region between Tennant Creek in the Northern Territory and east of Mount Isa in Queensland. Our results image major conductive structures up to 150 km deep in the lithosphere, such as the Carpentaria Conductivity Anomaly east of Mount Isa. This anomaly is a significant lithospheric-scale conductivity structure that shows spatial correlations with a major suture zone and known iron oxide–copper–gold deposits. Our results also identify similar features in several under-explored areas that are now considered to be prospective for mineral discovery. These observations provide a powerful means of selecting frontier regions for mineral exploration undercover.. <b>Citation:</b> Duan, J., Kyi, D., Jiang, W. and Costelloe, M., 2020. AusLAMP: imaging the Australian lithosphere for resource potential, an example from northern Australia. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.