Geochemistry and Nd isotope study of ultramafic mafic rocks from Southern Bundelkhand craton central India Implications for Archean mantle evolution crustal growth and PGE mineralization

Abstract

newlineThe Bundelkhand craton in Northcentral India preserves a composite mosaic of semi-circular newlineArchean continental nuclei, that occupies about ~26,000 sq. km. The craton has a very complex newlinegeological, metamorphic and tectonic history from ca. 3.8-2.5 Ga. Multidisciplinary research newlinestudies involving detailed field, petrological, geophysical, geochronologic, elemental and newlineisotope over three decades immensely contributed to our understanding of the fundamental newlinearchitecture as well as crust formation in the Bundelkhand craton. Recent studies suggest that newlinethe Bundelkhand craton can be divided into three crustal blocks: the northern, central, and newlinesouthern blocks. These blocks can be distinguished by their distinctive geological signatures, newlinelike basement TTG-type granitoids, greenstone assemblages, various granitoids, and ultramafic newlinemafic intrusive rocks, deformation, metamorphic events, and the degree of melting of the older newlinecrustal fragments. The Bundelkhand craton essentially consists of three major lithological newlineassociations including a vast area of Paleoarchean to Mesoarchean polyphase granitoids of newlineTTG affinity (3555-3270 Ma), Mesoarchean to Neoarchean volcano-sedimentary greenstone newlinesequences (2800-2500 Ma) and voluminous Neoarchean (2583-2536 Ma) high K- granitoids newlineincluding sanukitoids and anatectic granites. newlineThe present study is focused mainly on the Madawara ultramafic-mafic complex (MUC) with newlinean aim to understand the petrogenetic process and geodynamic context of ultramafic mafic newlinemagmatism of the southern part of the Bundelkhand craton. The southern part of the newlineBundelkhand craton preserves highand#8208;grade basement rocks of TTG affinity such as granitic newlinegneisses, gneisses, migmatite, amphibolites, and hornblendeand#8208;biotite gneisses. These rocks are newlineexposed around Rajola and north of Madawara. The lowand#8208;grade volcanoand#8208;sedimentary rocks such newlineas banded hematite-magnetite quartzite, quartzite, micaand#8208;schists, and amphibolites are exposed newlinearound Girar, Baraitha, and Badwar villages called as southern greenstone belt of