Fingerprints of Nickel Exploration in the Pulivendla-Vemula (P-V) sill in Cuddapah Basin:Geological Complexity and Discovery Potential

The increasing global demand for nickel, driven by its critical role in stainless steel production and emerging battery minerals technologies, has intensified exploration efforts in geologically diverse terrains. This study focuses on the Cuddapah Basin, a Proterozoic sedimentary basin in southern India, which presents a complex geological framework with promising yet underexplored potential for nickel mineralization. Through an integrated approach combining lithological mapping, geophysical surveys, and geochemical analysis, this paper present fingerprints of geochemical and geophysical signatures to target Nickel Exploration. The preliminary findings indicate the presence of ultramafic intrusions and favourable host rocks such as picritic sills which are typically associated with nickel sulfide deposits. The western margin of the Proterozoic-aged Cuddapah Basin contains gabbro and plagioclase bearing sills within the Tadapathri formations These sills have 4-28% MgO and 30-1050ppm Ni and they are characterized by elevated Th/Nb which is indicative of contamination by upper crustal material. The low MgO mafic magmas have one to two orders of magnitude viscosity higher than the picritic sill they are emplaced all along the Cuddapah basin margin. No Ni-Sulphide mineralization is known in this belt, but trace interstitial sulphide is present. The following features of the Pulivendla-Vemula sill complex indicate that the rocks are prospective for magmatic sulfide exploration:1. Tholeiitic lavas and sills were emplaced during extensional intra-cratonic rifting at a time of major Ni ore formation at ~1.9 Ga metallogenic epoch i.e late Proterozoic-Archaean in age.2. Un-deformed fresh differentiated ultramafic sills have a range in Ni concentration over a narrow interval of forsterite content with primary olivine 3. These sills and other sills in the footprint of regional magnetic and gravity anomalies possibly contain feeders where immiscible magmatic sulfides may have formed. correlating between Werner depth estimations and seismic data, particularly in pinpointing fault zones. These zones act as critical conduits for fluid migration from the mantle to the surface, playing a vital role in both tectonic interpretation and mineralexploration4. Despite the absence of magmatic sulfide mineralization and magmatic breccias, there is untested potential within the basin stratigraphy for the development of intrusions which have a magnetic and density signal, possibly in association with a structural break as well as a diagnostic electromagnetic signal from highly conductive sulfide mineralization. However, the geological complexity, including structural deformation and metamorphic overprints, poses significant challenges in locating economically viable deposits. The study underscores the importance of advanced exploration techniques and multidisciplinary data integration to improve discovery success rates. Ultimately, this work contributes valuable insights into the Ni-mineral prospectivity of the P-V Picritic Sill in western margin of Cuddapah Basin and highlights its potential as a frontier region to relook for nickel exploration in India.