b'PeopleNewsKate Robertson reports on uS study tourThe potential of magnetotellurics (MT) as an exploration tool is still to be fully realised, but the technique is capable of imaging deep conductive signatures of mineral systems across metres to hundreds of kilometres; highlighting prospective regions. The Australian lithospheric architecture magnetotelluric project (AusLAMP) is an exciting project, which will eventually result in deep sounding MT sites being located across the entire continent, and potentially across the continental shelf. The Geological Survey of South Australia (GSSA), along with collaborators, is using the currently available 3D modelling codes, to provide unprecedented views of the entire lithosphere beneath SA,The building in which I was working at the Lamont Doherty Earth Observatory, Columbia University, New York.down to 200 km. However, these codes assume that the electrical conductivity, the property we are imaging, is constant in all directions - a scalar quantity. However, many geological processes cause preferred orientations of geological structures or anisotropy. There are no currently available 3D inversion codes that consider anisotropy.In December 2019, I visited a research group at the Lamont Doherty Earth Observatory, Columbia university in New York led by Associate Professor Kerry Key, who is in the final stages of developing a 3D magnetotelluric modelling code, MARE3DEM, that can model complex anisotropic conductivity structure. During this visit we appliedSome of the large pool of marine MT instrumentation at Scripps Institute of Oceanography.the new software to our South Australian AusLAMP MT data, and our highereastern edge of the Gawler Craton.deep mineral systems signatures within resolution (1.5 - 5 km site spacing insteadThis conductor can be observed inSouth Australia, derived from our of 55 km site spacing of AusLAMP)AusLAMP models and previous MTAusLAMP MT models.Olympic Domain MT array in a projectsurveys, and correlates to surface that we will continue to develop. Weoccurrences of copper and gold. AMy trip was co-funded and supported look forward to presenting results at thevisit to Professor Steve Constable atby the Australian Geoscience Council, GSSAs Discovery Day 2020 and AEGCScripps Institute of Oceanography,a 34th IGC travel grant and the South 2021 in Brisbane. whilst in the uS, enabled furtherAustralian Department for Energy discussion and planning on futureand Mining. Iam very grateful for The Mare3DEM software is alsoworkflows for the recently acquiredthis support. The trip will enable suitable for modelling amphibiousmarine MT data. vast improvements in the accuracy (part land, part sea based) MT data,of Australian conductivity models, which will be useful for the MT dataAlso, while I was in the uS, I attendedwhich are critical for the quantitative acquired in November 2019 acrossthe 2019 AGu Fall Workshop in Saninterpretation of Australian MT data, and the Spencer Gulf in SA by the GSSA,Francisco - the worlds largest gatheringevaluation of implications for mineral SCRIPPS Institute of Oceanography,of geophysicists. The workshoppotential analysis.AuScope, university of Adelaide andgave me personal development and Geoscience Australia. These datanetworking opportunities, along with were acquired to better delineate thethe opportunity to promote the workKate Robertson southern extent of the large crustalwe are doing at the GSSA. I focusedGeological Survey of South Australia conductor that extends down theon sharing our understanding of theKate.Robertson2@sa.gov.auJuNE 2020 PREVIEW 10'