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The Pichhore orbicular granite near Kutawali village, Shivpuri district, Madhya Pradesh, has been dated to about 2.56 billion years old — the world's second-oldest known orbicular rock, after a formation in Western Australia.
Scientists used Uranium-Lead (U-Pb) zircon dating; some inherited zircon crystals in the sample were as old as 3.5 billion years.
The rock lies within the Bundelkhand Craton, one of India's oldest stable geological blocks, and the study was published in the journal Geosystems and Geoenvironment by researchers from BHU, IIT Kanpur, IISER Berhampur, University of Campinas (Brazil) and JAIST (Japan).
Orbicular granite is a rare igneous rock containing spherical 'orbicules' (often quartz-feldspar, with tree-ring-like concentric layers). A craton is a stable, largely undeformed part of continental crust that has persisted over billions of years — the Bundelkhand Craton is one of India's oldest such blocks.
Simple Analogy: Orbicules are like tree rings frozen inside rock instead of wood, recording growth stages within a mineral mass rather than a tree trunk.
Currently the world's oldest known orbicular rock formation; the Pichhore granite (2.56 billion years) ranks second-oldest globally.
GS Paper I (Geography - Physical Geography/Geomorphology) & GS Paper III (Science - Earth Sciences)
A stable, ancient part of continental crust that has remained largely undeformed for long geological periods
A radiometric dating method using zircon crystals' uranium-to-lead decay to determine rock ages, reliable over billions of years