Geochemical and Geomorphic Signatures of the Probable Complex Impact Structure in India: The Girnar Crater, Saurashtra, Gujarat
Abstract
The Girnar circular structure in Saurashtra region of Western India has long been interrupted primarily as a volcanic edifice associated with Deccan magmatism. However, emerging geochemical, petrographic and geomorphic evidence suggests that the structure may be represents a deeply eroded complex terrestrial impact crater subsequently modified by volcanic and tectonic processes. Circular basin morphology, Central uplift and radial –concentric drainage patterns align with recognized crater architectures. Whole rock geochemical analysis show relative enrichment in siderophile elements (Ni,Co,Cr) and elevated HFSE ratios, suggesting a non-magmatic contribution. Petrographic field observations of shock microstructures, melt-like textures and breciation further support transient high-pressure deformation. These signals differ markedly from typical Deccan magmatic signatures. Samples were analysed using (XRF) X-ray Fluorescence, Indicatively Coupled Plasma Mass Spectrometry (ICP-MS) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) Results of the study imply that a large impact event may have influenced subsequent volcanism and landscape evolution of Saurashtra region. As like Mistastin crater (Kamestastin crater), Canada It is also a rare example of impact-volcanic coupling on the Indian sub continental crust.
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