b'Geophysics in the surveysNewsGeological Survey of South Australia: UpdateThe geophysicists at the Geologicalcoming months, the data will be analysedmost recent state magnetic image, and Survey of South Australia (GSSA) wouldto produce seismic velocity models ofanticipate a similar body of work for the love to write a feature article on one ofthe crust and mantle across the central- new radiometric grids. We are exploring our major projects, but the reality is thateastern Gawler Craton and greatlyways to automate the creation of the we dont have a new and shiny productconstrain local seismicity for the region. report book given the large amount of to show off right at this moment. Sonear-repeated information that needs instead, here is a quick run-down of ourAdditionally, the GSSA has installed theconsideration. We anticipate the release various projects. majority of sites of Geoscience Australiasof these report books later in 2022.AusArray 2 x 2 degree grid across South The Gawler Phase 2 geophysicalAustralia. The array will be part of theThe task of processing geophysical acquisition is underway, withnational EFTF seismic array to create asurvey data from exploration companies Zonge Engineering commencingbackbone seismic velocity model of theexploring in South Australia remains magnetotelluric acquisition in theAustralian lithosphere. an ongoing job for GSSA geophysicists. central Gawler Craton in SouthSince the previous data release we Australia. MT stations are spaced atThe GSSA is creating a new suite of State- have lined up over 30 airborne surveys approximately 12.5 km intervals in awide geophysical imagery, focusing onacquired between 1961 and 2011. These regular grid pattern, with closer spacinggravity and radiometrics. Following thewill be made available online via SARIG. along two detailed traverses. Thesemethods described in Katona (2017), weWe are currently updating the software traverses cross the Challenger Goldare creating a Spherical Cap Bouguerin the backend of SARIG that allows the mine and Tarcoola areas. We anticipateGravity State-wide image. This followssurveys to be cookie-cut to a users area gravity acquisition - to be undertakenon from our gravity module updateof interest. Once the update is complete by Daishsat Geodetic Surveyors - willwhere we have flagged stations thatthese surveys will be available for public commence in August. Gravity stationsdo not contribute to the overall stateconsumption.will be acquired on a regular 2 x 2 kmimage. These stations are generally either grid, with a detailed 1 x 1 km grid overduplicate readings in the database -Finally, the GSSA welcomed three Year the Challenger mine. with changes in number precision that10 work experience students for a result in gridding artefacts - or surveysthree-day stint with the GSSA. It was Acquisition is continuing for thewhere elevation data are not suitablean opportunity to introduce them to collaborative GSSA-Geological Surveyto calculate the Bouguer Anomaly. Theeverything geoscientific in SA. The of Victoria magnetotelluric surveycreation of the State-wide image is angeophysics team introduced the students along a 750 km long profile to augmentiterative GIS and gridding process, and weto the basics of gravity acquisition, taking Geoscience Australias EFTF 2 projectanticipate this product to be available in athem on a gravity calibration run to the following the DCD2 Geosciencefew months. Burnside Rugby Club and Norton Summit Australia seismic reflection line. Two- Hotel in Adelaides suburbs. The students thirds of the MT stations have beenA new suite of State-wide radiometricwere grateful for the opportunity to acquired in Victoria and eastern SAimages are also in the works,explore a branch of science that they with the remaining data to be acquiredincorporating recently acquired GCASwere not aware even existed.in September. Nominal site spacing is(Gawler Craton Airborne Survey) data, 3-4 km and will highlight the crustal andas well as the full catalogue of South upper mantle structure associated withAustralian airborne radiometric data.Referencethe Delamerian and Lachlan Orogens.As in previous State-wide radiometric It further constrains the geologicalimages, these will be created usingKatona, L., 2017. Gridding of South framework for the recently completedIntrepid Gridmerge software. WeAustralian Ground Gravity Data, using GSSAs southern MinexCRC drillinganticipate the suite of grids will be readythe Supervised Variable Density campaign. late in 2022. Method. 10.13140/RG.2.2.17491.37923The AusArray SA survey has now beenOne of our most frequent data demobilised after recording ambientrequests is for detailed processingPhilip Heath, Stephan Thiel, Gary Reed, noise and teleseismic events over theinformation regarding the state grids.Tim Keeping, Gary Reed and Laz Katona last 18 months across 35 stations spacedWe are currently compiling a report bookGeological Survey of South Australia approximately 50 km apart. Over thedetailing the processes that went into thePhilip.Heath@sa.gov.au25 PREVIEW AUGUST 2022'