• Structural studies and their bearing on the Early Precambrian history of the Dharwar tectonic province, southern India

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      https://www.ias.ac.in/article/fulltext/jess/105/04/0379-0412

    • Keywords

       

      Dharwar Supergroup; Early Precambrian; India; Peninsular Gneiss; structural history

    • Abstract

       

      In the Dharwar tectonic province, the Peninsular Gneiss was considered to mark an event separating the deposition of the older supracrustal Sargur Group and the younger supracrustal Dharwar Supergroup. Compelling evidence for the evolution of the Peninsular Gneiss, a polyphase migmatite, spanning over almost a billion years from 3500 Ma to 2500 Ma negates a stratigraphic status for this complex, so that the decisive argument for separating the older and younger supracrustal groups loses its basis. Correlatable sequence of superposed folding in all the supracrustal rocks, the Peninsular Gneiss and the banded granulites, indicate that the gneiss ‘basement’ deformed in a ductile manner along with the cover rocks. An angular unconformity between the Sargur Group and the Dharwar Super-group, suggested from some areas in recent years, has been shown to be untenable on the basis of detailed studies, A number of small enclaves distributed throughout the gneissic terrane, with an earlier deformational, metamorphic and migmatitic history, provide the only clue to the oldest component which has now been extensively reworked.

    • Author Affiliations

       

      K Naha1 R Srinivasan2 D Mukhopadhyay3

      1. Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur - 721 302, India
      2. National Geophysical Research Institute, Uppal Road, Hyderabad - 500 007, India
      3. Department of Geology, University of Calcutta, 35 Ballygunge Circular Road, Calcutta - 700 019, India
    • Dates

       
  • Journal of Earth System Science | News

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