• Alkaline intrusion in a granulite ensemble in the eastern ghats belt, India: Shear zone pathway and a pull-apart structure

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    • Keywords

       

      Alkaline magmatism; Eastern Ghats belt; pull-apart structure; plume tectonics

    • Abstract

       

      The alkaline complex of Koraput, Orissa, India, is one of several bodies in the high-grade Eastern Ghats belt, but this one is an integral part of the high-grade belt and remote from the western boundary against the Bastar craton. The Koraput complex forms a lozenge-shaped intrusion into the metapelitic granulites and is bounded by shear zones. The combined effect of movement along these shear zones, is a northeasterly elongated sygmoidal cavity with maximum width along the northwesterly trending Reidel shear. Thus the Koraput alkaline complex can be considered to have been emplaced in a pull-apart structure, developed in the granulitic country rocks. Moreover, in view of the fact that the western margin of the high-grade Eastern Ghats belt bears clear evidence of collisional features, rather than that of rifting or break-up, the rift-valley model for the alkaline magmatism in this high-grade belt appears untenable.

    • Author Affiliations

       

      S Bhattacharya1 Rajib Kar2

      1. Geological Studies Unit, Indian Statistical Institute, 203 B. T. Road, Kolkata - 700 108, India
      2. Department of Geology, J. K. College, Purulia - 723 101, India
    • Dates

       
  • Journal of Earth System Science | News

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