Assessment of Exploration Potential of Strategic Minerals in the Gujarat State

In a bid to harness the power of cutting-edge technologies, the Gujarat Government has partnered with Geovale Services to unlock the state's strategic mineral potential. With Geovale's expertise, the project aims to strategically evaluate the mineral potential targets, in accordance with the geological, geomorphological, and environmental settings of the state. This initiative not only seeks to reduce India's reliance on strategic mineral imports but also resonates with national objectives of bolstering renewable energy and curbing carbon emissions. It's a forward-looking endeavor poised to redefine India's strategic mineral landscape while advancing its environmental commitments.

Geovale’s Approach

This analysis adopts a paradigm akin to pioneering global studies in critical mineral exploration, employing a 'Mineral System Analysis' (MSA) framework. MSA integrates data from various sources like GSI, AMD, GMRDS, and publications, offering a holistic understanding of geological information within a tectonostratigraphic context. It unravels the mineralization process from metal sourcing to deposition, considering four key parameters: source, fluid, pathways, and trap. MSA is dynamic, evolving with new data, providing a comprehensive approach to evaluating geological terrains.

Following the comprehensive analysis conducted using the Mineral System Analysis framework, a short-duration fieldwork was conducted to validate and augment the geological information gathered. This on-ground exploration effort served to corroborate findings and enhance the accuracy of the data compiled from various sources. Additionally, it facilitated a firsthand assessment of a few of the potential mineral targets. Subsequently, a focused feasibility study was undertaken, leveraging insights gleaned from both the fieldwork and the preceding analytical endeavors, to evaluate the viability of exploration ventures on a smaller scale.

Mineral System Analysis’ of Gujarat’s Geology

Gujarat's geological diversity, spanning in age from Archean to Quaternary, offers a treasure trove for strategic mineral exploration. Across its three physiographic domains of Mainland Gujarat, Kachchh Peninsula, and Saurashtra Peninsula, eight distinct classes of strategic mineral potentials identified including volcano-sedimentary, magmatic sulphide, granite, alkaline dyke/plug, carbonatite, laterite, sediment, and brine hosted deposits.

Mainland Gujarat showcases a range of geological formations from ancient basement gneissic complexes to later granitoid intrusions, including Neoproterozoic types like SAG, GG, and IG. The region also features isolated Cretaceous formations. Significant mineralization potential exists in the contact zones of these formations, particularly for rare metals such as REE, P, Sn, W, Ta, Li, Nb, and Zr. The eastern area's Paleocene carbonatite and alkali dykes, especially around the Ambadonger complex, also present notable opportunities for mining these rare metals.

The Kachchh Peninsula in north-west Gujarat, shaped like a hammerhead, has a geological history spanning around 250 million years and features unique stratigraphy. The region includes Deccan Traps and infra-traps, with a variety of tectonostratigraphic units containing lignite, clay, phosphorite, and gypsum, all rich in strategic and critical metals like REE. In the south-central area, Mesozoic sedimentary rocks are intruded by pre-Deccan mafic alkaline plugs and lamprophyres, which are rich sources of REE, Au, V, Cu, PGE, and sapphire. The Great Rann of Kachchh, a salt-encrusted wasteland, contains the Meruda Takar alkaline complex, linked to similar formations in Pakistan and Rajasthan, and holds potential for Li, Nb, and REE mineralization. The brine and associated clay deposits in the Great Rann also show potential for Li and heavy REE.

The Saurashtra Peninsula, shaped like a triangle in Gujarat, is mostly covered by Palaeocene Deccan Volcanics, which include tholeiites, picritic basalts, and granophyre. Mesozoic and Tertiary sediments, which both underlie and overlie these volcanics, are exposed in the southern part of the peninsula. These granophyric complexes and picritic basalts within the Deccan Volcanics are potential hosts for critical metals like HREE, Au, Nb, Zr, and PGE-Ni-Cu. Additionally, lignite and clay deposits in the southern Mesozoic-Tertiary layers may also contain REE.

Conclusion

The introduction of the MSA framework for the assessment of Gujarat's geology in the context of critical mineral exploration marks a pioneering advancement in India's scientific landscape, enriching the nation's strategic mineral potential map for future endeavors. Through a comprehensive evaluation, 29 potential mineralized zones have been delineated for G4 level exploration, offering both primary and secondary prospects. Presently, three priority blocks are undergoing exploration with funding support from the Ministry of Mines' NMET program, aimed at capitalizing on immediate opportunities. This case study serves as a testament to our adeptness in amalgamating geological data with technical proficiency, thereby enhancing the identification of potential strategic and/or critical mineral targets, and consequently augmenting the success rate of conceptual exploration endeavors.