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      https://www.ias.ac.in/article/fulltext/jess/129/0179

    • Keywords

       

      Petrography; geochemistry; Barail Sandstone; Surma basin; Mizoram.

    • Abstract

       

      The Oligocene Barail Sandstones of Surma basin from parts of Champhai District of Mizoram, northeast India has been studied for their tectono-provenance setting using petrography and geochemistry. The studied sandstones are poor to moderately sorted, subarkosic to sub-litharenite and show dominance of quartz (avg. 54.46%) followed by feldspars (avg. 7.22%), rock fragments (avg. 4.98%), mica (avg. 5.89%), matrix (avg. 14.47%) and cement (avg. 12.98%). Dominance of polycrystalline and undulatory monocrystalline quartz indicates contribution from medium grade metamorphic sources, primarily of granite gneisses. High concentration of SiO$_{2}$ with moderate to low concentration of Al$_{2}$O$_{3}$, Fe$_{2}$O$_{3}$, MgO, Na$_{2}$O and K$_{2}$O resembles the composition of upper continental crust. Moreover, moderate to high concentration of Th and V, depleted value of Ni along with TiO$_{2}$/Zr suggests derivation of sediments from felsic sources. The ratios of Eu/Eu* (avg. 0.63) and La$_{\rm {N}}$/Lu$_{\rm{N}}$ bears resemblance with the upper continental crust. Overall analyses show that the sediments were derived from the felsic terrain of neighbouring orogens probably represented by granite-gneisses and have undergone a moderate degree of weathering (avg. values of CIA: 70.20, CIW: 81.03, PIA: 77.63, WIP: 38.45, ICV: 1.06, I$_{\rm{w}}$ = 2) in a semi-humid to humid climatic conditions [Q$_{\rm{p}}$ /(F + RF):Q$_{\rm{t}}$ /(F + RF) = 0.20].

    • Author Affiliations

       

      PRADIP BORGOHAIN1 FARUQUE HUSSAIN M2 DEVOJIT BEZBARUAH3 VANTHANGLIANA V4 PARAKH PROTIM PHUKAN1 MANASH PRATIM GOGOI1 BUBUL BHARALI4

      1. Department of Petroleum Technology, Dibrugarh University, Dibrugarh, Assam 786 004, India.
      2. Department of Earth Science, Assam University, Silchar, Assam 788 011, India.
      3. Department of Applied Geology, Dibrugarh University, Dibrugarh, Assam 786 004, India.
      4. Department of Geology, Pachhunga University College, Aizawl, Mizoram 796 001, India.
    • Dates

       
  • Journal of Earth System Science | News

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