Frewena Group Project AMAGRAD GDC Final Report East Tennant, NT

Abstract

This Geophysics and Drilling Collaboration (GDC) grant was awarded funding of $100,000 to undertake detailed airborne magnetic-radiometric surveying over 3,497km2 in the emerging East Tennant region of the Northern Territory. Following innovative target generation by the Tenure Holders, in conjunction with the excellent precompetitive geophysical surveying and stratigraphic drilling by Geoscience Australia, the Northern Territory Geological Survey, and MinEx CRC, several standout exploration projects - Frewena Fable, Frewena East, Frewena Far East and Frewena Frontier - have been developed by Inca Minerals that are considered highly prospective to host large scale Iron Ore Copper-Gold and SEDEX mineralisation. Exploration and generative work on these Projects, to date, has made use of regional geophysical datasets and various survey results from Geoscience Australia and the Northern Territory Geological Survey that are specific to the East Tennant region. While these datasets have been effective for prioritising regional scale features, higher resolution magnetic-radiometric surveying will greatly aid a shift towards prospect scale vectoring that is hoped to ultimately lead to successful mineral resource discovery. Detailed magnetic-radiometric surveying completed under this grant covered the Frewena East, Frewena Far East, and Frewena Frontier Projects, and built on the 2020 GDC supported program successfully undertaken by Inca Minerals that covered 1,182km2 over the Frewena Fable and Frewena Far East Projects. The 2021 program substantially expanded on this work covering a further area of 3,497km2, representing a large portion of the East Tennant region. Geophysical surveying was undertaken by MagSpec Airborne Surveys Pty Ltd between 8 September and 18 December 2021, and was based at the Barkly Homestead. Survey design and processing was undertaken by Resource Potentials Pty Ltd. Captured data has undergone initial processing and filtering to produce various images of magnetics, radiometrics, and local digital terrain models. Data resolution has been significantly increased by more than tenfold with image cell size, or pixels, now measuring c. 8m by 8m in size. The datasets will improve geological understanding of the region, and in particular the structural architecture. Additional, filtering and interpretation of detailed magnetics - outside the scope of this GDC grant - is ongoing at the time of writing and will be included in future tenure annual reports. This work aims to delineate subtle, coherent bodies in the subsurface that may relate to large scale hydrothermal mineralisation and alteration. While the East Tennant region has rapidly emerged as a hot spot for potential Iron Ore Copper-Gold and SEDEX mineralisation, the vast size of the area dictates that exploration endeavours need to be efficient and systematic in their approach. The detailed magnetic-radiometric surveying completed under this GDC grant aimed to provide data to bridge the gap between regional and prospect scale vectoring. Ensuring subsequent, higher cost exploration techniques are well placed will allow the best chance of mineral resource discovery.