b'Geophysics in the SurveysNewsGeological Survey of South Australia: An updateData now available from GCAS Regions 1A and 1BThe Gawler Craton Airborne Survey (GCAS) team are pleased to announce that the data and images for survey region 1A (Tallaringa North) and 1B (Tallaringa South), completed by Thomson Aviation Airborne Geophysical Survey, are now available for download. These highly anticipated data releases cover the north-western Gawler Craton, a true greenfields exploration frontier.Data packages can be downloaded directly from the Gawler Craton Airborne Survey Community Information page and via SARIG (Figure 1).The vertical magnetic gradient images of GCAS regions 1A and 1B, highlighting complex geological structure and detail, is shown in Figure 2.Figure 1.GCAS data availability. Clicking on a survey region displays a link when data is available. We anticipate that data from theClicking the link opens a new window with survey information and data downloads.remaining blocks of the Gawler Craton Airborne Survey (Blocks 5, 6 and 9b) will released before the end of 2019. Further information can be found at energymining.sa.gov.au/minerals/gcasPhilip Heath and Laz KatonaPhilip.heath@sa.gov.auLaz.Katona@sa.gov.auMarine MT deploymentStephan Thiel and Kate Robertson headed to Port Lincoln last weekend, for an international geophysics collaboration with world leaders in marine magnetotellurics (MT), Scripps Institute of Oceanography, along with partners Geoscience Australia and the University of Adelaide. All hands were on deck for the deployment of 12 marine MT instruments in the Spencer Gulf, the first of its kind in South Australia in over 20 years (Figure 3). Funding for this project comes from the Geological Survey of South Australia, Geoscience Australia and AuScope. This pilot project expands the coverage of land MT sites to the continental shelfgeology does not stop at the coast line!This survey will fill a significant gap in MT data coverage across the important eastern margin of the prospective Gawler Craton with a view to possibly extendingFigure 2.Magnetic intensity image 1VD of reduced to pole TMI, imaging from north-west to south-east: The the national AusLAMP project onto theNawa Domain, Mabel Creek Ridge, Tallaringa Trough, Karari Shear Zone and Christie Domain.DECEMBER 2019 PREVIEW 30'