• Evidence of Archaean metamorphism from the Yerrabali schist belt of Eastern Dharwar craton from EPMA dating of monazite

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/129/0073

    • Keywords

       

      Yerrabali schist belt; monazite dating; Eastern Dharwar craton; EPMA chemical dating

    • Abstract

       

      The Dharwar craton is divided in to the Western and Eastern Dharwar craton (WDC and EDC) by the N–S trending Chitradurga Shear zone. The EDC mainly consists of late Archean granites interspersed with N–S trending linear schist belts. The Yerrabali Schst belt (YSB) is located at the north-eastern corner of the EDC, near the Karimnagar granulite belt. The YSB is metamorphosed in middle-upper amphibolite facies and consists of Banded Magnetite Quartzite (BMQ), ferruginous quartzite, ultramafics, quartz–cordierite–gedrite $\pm$ garnet bearing quartzite, dolomite, amphibolite, deformed metapyroxenite, tremolite schist, sillimanite–garnet–cordierite schist, and dolerite dykes. We have dated monazites in the sillimanite–garnet–cordierite schist, exposed at the SW part of the YSB by EPMA chemical method. So far no dates are available from the YSB. The monazite chemical ages with three distinct populations, viz., $2658 \pm 42$, $2817 \pm 19$ and $3097 \pm 34 \rm{Ma}$, probably correspond to three distinct metamorphic phases. The peak metamorphism at around 2800 Ma corresponds with the garnet and cordierite growth. A temperature of $673^{0}\rm{C}$ and a pressure of 4.7 kb have been estimated for peak metamorphism.

    • Author Affiliations

       

      SANKHA DAS1 SANDIP NANDY2 G RAMACHANDRAN3 SHAMPA KHAN2

      1. National Mission-IA, Geological Survey of India, Kolkata, India.
      2. EPMA Laboratory, Geological Survey of India, Kolkata, India.
      3. State Unit Telangana, Geological Survey of India, Hyderabad, India.
    • Dates

       
  • 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

© 2021-2022 Indian Academy of Sciences, Bengaluru.