b'Geophysics in the SurveysNewsdata downloads, 1672 of these areby Investigator Resources. The survey downloads of the new survey data andarea covers the Carapateena IOCG 536 downloads are the value-addeddeposit and the recently discovered and depth-model data packages.Oak Dam is on the northern edge of GCAS data has more than 28 000 viewsthe array, and other prospects and on the Department for Energy anddeposits include Emmie Bluff, Punt Hill Mining (DEM) Website. While 60% ofand Mt Gunson. The results of 3D and the GCAS data is already available to2D magnetotelluric (MT) inversions the public as free downloads, DEMof the data will be presented at the expect to release 100% over theAustralasian Exploration Geoscience coming months. Convention (Thiel, Robertson & Jiang, In addition to the data releases, DEMScale reduction using Magnetotellurics have partnered with CSIRO to provide a a mineral exploration example from comprehensive suite of value-added datathe Olympic Domain, South Australia) products derived from the GCAS data.and at Discovery Day on 28 November These products include filtered magneticFigure 2.The pimples on the Nullarbor Plain areat the Adelaide Convention Centre. images and magnetic modelling thatshort-wavelength features prominent in the 1VD(Figure 3)predicts the depth to economic rocksmagnetics. A further seven AusLAMP sites have been below the surface. To date, theseacquired in the far west coast region of value-added releases have providedcarried out some modelling work. TheSouth Australia, to replace existing sites new information and data across somegravity stations were spaced at 10 mwith poor data quality. These have now 72 000 km2. intervals and magnetic stations at 5 mbeen incorporated into the AusLAMP The Department for Energy and Miningintervals along traverses over each ofdata package that is available for would like to thank and congratulatethe selected pimples. download on SARIG.the airborne geophysics suppliers andThe second feature we examined wasIn October we will set sail for an exciting contractors to the GCAS: MagSpeca Gairdner Dolerite. These dykes areendeavour with the planned acquisition Airborne Surveys Pty Ltd, Sandera prominent geophysical feature inof 24 marine MT sites (Figure 4), a Geophysics, Thomson Aviation AirborneSouth Australia and are often seencollaborative and co-funded project by Geophysical and Survey, GPX Surveys,as a hindrance to exploration as theythe Geological Survey of South Australia, Baigent Geosciences and Mintymask the prospective geology. Theythe University of Adelaide, Geoscience Geophysics. The Department would alsoare long, linear, northwest-southeastAustralia and Scripps Institute of like to acknowledge the cooperationstriking features that cover much ofOceanography, with instruments of the Department of Defence and thecentral South Australia. We undertook aloaned from the Scripps Institute of assistance of collaborative partnersdetailed ground magnetic and gravityOceanography, San Diego, United States Geoscience Australia and CSIRO.profile over the top of one prominentby Professor Steve Constable. This survey Laz Katonadyke near Lake MacFarlane. The datawill build upon the resistivity model laz.katona@sa.gov.au allows us to model the dyke with aacross the Gawler Craton provided by higher level of confidence than fromAusLAMP, and will help to constrain airborne data, and the gravity data Gravity allows us to see if there is a coincident Geophysicists from the GSSA and CSIROgravity anomaly. Gravity stations recently undertook a short fieldtripwere acquired at 50 m intervals with a to examine two types of geophysical25 m infill directly over the magnetic features that have been well definedanomaly, and ground magnetic data by the GCAS. The first of these featurewas acquired at 25 m intervals for the are the pimples seen throughoutlength of the 3.5 km line. Stay tuned the magnetic 1VD images over theto future ASEG publications for the full Nullarbor Plain. These pimples arereport!particularly noticeable in GCAS regionPhilip Heath 4b (see Figure 2). The pimples extendPhilip.heath@sa.gov.authroughout the Nullarbor and well into Western Australia, and little isMagnetotelluricsknown about them. Their distribution is not random, it is patterned, butThe final EDI files (combined audio-the material causing the magneticmagnetotelluric and broadband signal is unknown. There is somemagnetotelluric) are available on SARIG correspondence between their(https://map.sarig.sa.gov.au/Shortcut/distribution and the distributionMTInterpreted) for the Olympic Domain of surficial sandy features, but theMagnetotelluric Survey. This project was relationship isnt consistent. Infunded by PACE Copper, and the tender conjunction with CSIRO, we undertookprocess was managed by Geoscience ground magnetics and microgravityAustralia. There are 333 sites availableFigure 3.Locations of MT sites across the over a selection of the pimples andfor download, including six sites fundedOlympic Domain infill region.AUGUST 2019 PREVIEW 26'