• Origin of the Neoarchean granites from the southeastern margin of the Western Ghats greenstone belt, Dharwar Craton: Implications for crustal evolution in the Western Dharwar Craton

    • Fulltext


        Click here to view fulltext PDF

      Permanent link:

    • Keywords


      Peraluminous granites; Narasiparvatha Formation; WDC; crystal size distribution (CSD); crustal evolution.

    • Abstract


      The field, crystal size distribution, mineral-chemistry and bulk-rock geochemical study on the felsic magmatic rocks (granite and associated rhyolites) of the Western Ghats belt, Dharwar Craton, has been presented for the first time in this contribution. These Neoarchean felsic magmatic rocks occur as massive plugs and lensoidal bands running for several meters to kilometres, with a general trend of NNW–SSE. These rocks are characterised by the ubiquitous presence of biotite and muscovite and are devoid of amphiboles. These rocks show evidence of textural coarsening but show no evidence of magma mixing or assimilation. The petrogenetic studies indicate that the partial melting of tonalite–trondhjemite–granodiorite (TTG) crust together with a considerable amount of Al-rich sediments has resulted in the peraluminous granitic melt source. This melt, subsequently, was mobilised to shallow crustal levels where it was emplaced along the axial planes of F1 folds before it was erupted on to the surface, giving rise to rhyolites. The similarities in the field, mineralogical and geochemical characteristics amongst ${\sim}$2.61 Ga old felsic volcanic rocks of the different greenstone belts in the Western Dharwar Craton (WDC) suggest that they were all derived from the partial melting of ${\ge}$3.1 Ga felsic crust with a minor input of metasedimentary units at mid-crustal levels. The felsic volcanic rocks show evidence of emplacement in the active plate boundary, the interior of WDC.

    • Author Affiliations



      1. Ore Research and Exploration Group (ORE-G), Department of Geology, Central University of Kerala, Kasaragod, Kerala 671 320, India.
    • Dates

    • Supplementary Material

  • Journal of Earth System Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.