• Grenvillian thermal event and remnant charnockite: Isotopic evidence from the Chilka Lake granulite-migmatite suite in the Eastern Ghats belt, India

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    • Keywords

       

      Granite-migmatite; Grenvillian event; zircon population; remnant charnockite

    • Abstract

       

      Spectacular exposures of granulite-migmatite occur in the Chilka Lake area of the Eastern Ghats belt. The garnetiferous granite gneiss of peraluminous granitic composition, often contains restitic metapelite inclusions and is demonstrably a product of biotite-dehydration melting in pelitic rocks. On the other hand, older layers and bands of charnockitic rocks frequently occur as dismembered patches within the peraluminous granite, thus imparting a measled appearance of the granite exposures.

      The partial melting and emplacement of the peraluminous granite represent the Grenvillian thermal event, as evidenced by Rb-Sr whole rock and Pb-Pb zircon dating. On the other hand, minor patches of charnockite represent migmatized relict, as evidenced by some older zircons, in addition to those of Grenvillian age.

    • Author Affiliations

       

      S Bhattacharya1 M P Deomurari2 W Teixeira3

      1. Indian Statistical Institute, 203 B.T. Road, Calcutta - 700 035, India
      2. Physical Research Laboratory, Ahmedabad, India
      3. Institute of Geosciences, Sao Paulo University, Brazil
    • Dates

       
  • Journal of Earth System Science | News

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