Critical mineral pathfinder targeting in the Aravalli basement (northwest India) calibrated against age and tectonically-matched Western Australian analogues using the AuScope EarthBank platform

Bhavik Harish Lodhia , Princy Agrahari, Aditya Priyadarshi, Brent I.A. McInnes

Critical mineral element fingerprints established in Australian regional geochemistry could accelerate exploration in geologically comparable but less-characterised terranes of north-west India, provided that a defensible basis for comparison can be established. We present a drainage-based method for identifying age and tectonically-matched Australian analogues for north-west Indian stream-sediment geochemistry, for testing whether pathfinder element signatures transfer between them, and for mapping the transferred signatures across the Indian drainage catchments. Sample sets were defined on both continents by drainage containment, tracing each stream-sediment catchment through level-12 hydrological sub-basins and retaining only samples whose upstream catchment lies within a target basement domain. In northwest India these are the Archaean Mangalwar Complex and the Palaeoproterozoic Sandmata Complex of the Aravalli Craton. In Western Australia, they are the coeval Palaeoproterozoic terranes of Western Australia and the Youanmi and Narryer terranes of the Yilgarn Craton. From these sets, we build 20 robust analogue pairs, matched on weathering-robust provenance ratios standardised within each survey and all of which are mutual nearest neighbours at a median separation of less than half a standard deviation. Testing against an independent set of critical mineral pathfinder elements shows that the light rare-earth signature transfers significantly between matched catchments and survives false-discovery-rate control, whereas the heavy rare-earth signature falls just short of that threshold and the hydraulically sorted heavy minerals, such as zircon and titanium oxides, do not transfer. Applying the transferable Australian fingerprint to the Indian samples maps the drainage catchments of the Aravalli basement where the light rare-earth signature is elevated. Hence, Australian critical mineral fingerprints can be carried across to Indian stream-sediment data to map the catchment-scale rare-earth signature, from which exploration hypotheses can be framed and tested.