Final Report Geophysics Collaboration for East Tanami Project AEM Survey 2019

Abstract

The Geophysics Collaboration program covered Asian Minerals Pty Ltd.'s (Asian Minerals) entire East Tanami project area, of 6 Exploration licences, an area of 4,255km2. This survey was incorporated into Geoscience Australia's (GA's) Exploring For The Future (EFTF) program, a TEMPEST Airborne Electromagnetic (AEM) Survey executed by CGG Aviation (Australia) Pty Ltd on behalf of GA. The Asian Minerals survey totalled 1,384-line km, The East Tanami survey commenced on the 22 September 2019 and was completed on 25 September 2019. The East Tanami project area was applied for by Asian Minerals in 2002 and was granted after negotiating an Exploration Deed with Central Land Council (CLC) on behalf of the Traditional Owners, the Karlantijpa North Aboriginal Land Trust, in March 2018. Delays have been experienced in gaining access for reconnaissance surveys and the objective of the AEM survey is to provide baseline start-up geophysical and geological understanding of a previously almost totally unknown portion on the NT. The AEM survey was expected to enhance target selection to enable focusing of the site clearance work to the most prospective portions of the holdings and access to these. The initially identified targets of the survey were diverse, but all might have a response from an AEM survey: a. Diamondiferous kimberlites or emplacements of other valuable minerals in association with a pronounced diatreme structure identified from the NTGS 2002 Buchanan Aeromagnetic survey, b. The Tomkinson Province terrain, with the possibility of strata- bound conductive manganese and Sabkha and VMS styles of mineralisation, suspected as a result of NTGS aeromagnetic coverage of other parts of the project area, particularly the 1999 South Lake Woods survey, and c. Additionally, augmentation of remotely sensed imagery to classify regolith and potential sources of subsurface water for access, logistics and exploration planning. The data provided to Asian Minerals by GA were field processed EM data as received from CGG. These were subjected to preliminary checks by GA before being made available to Asian Minerals. Further processing of the data received from GA was commissioned by Asian Minerals from Mira Geoscience, who performed conductivity-depth transformation of the data using the program EmaxAir and produced conductivitydepth sections and depth slices of the field data and in addition the 20km- spaced lines from the EFTF AusAEM (Qld-NT) Year 1 Survey where these crossed the area of interest. Interpretation of the survey in conjunction with data from earlier NTGS airborne magnetic and radiometric surveys (The South Lake Woods (1999), and Buchanan (2002) surveys in particular) is proceeding and will be used to plan further work on the project area as well as EL reductions.