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      https://www.ias.ac.in/article/fulltext/jess/127/06/0088

    • Keywords

       

      Sub-Himalaya; cross-section balancing; brittle fault

    • Abstract

       

      The Neogene–Quaternary Siwalik foreland fold and thrust belt is studied for better understanding of tectonics along the Kameng river section of Arunachal Pradesh, India. The Kimi, Dafla, Subansiri, and the Kimin Formation correspond to Lower, Middle and Upper Siwaliks, respectively. The lithology in the foreland basin is dominantly sandstones, siltstones, claystones, carbonaceous shales, and boulder beds in the upper part. The structural style of the sedimentary sequence from the Main Boundary Thrust southward shows first order ramp-flat geometry. The brittle shear transfers slip across glide horizons to shallower depth. Repeated splay generations from a major regional-scale floor transfers slip from one glidehorizon to another that shortens and thickens the crust. In the micro-scale, the lithological response in the structural development is well documented as pressure solution seams and other diagenetic deformation signatures. The basement asperity plays a significant role as the moving thrust front produced a majorlateral ramp. The differential movement of the mountain front on both sides of the ramp is decipherable. This is especially true at the western part of the SE flowing Kameng river. The tectonic evolution of the area initiated with slip along the MBT $\sim11 \rm{Ma}$ ago along with the deposition of the Siwalik sediments. With southward propagation of the mountain front, the foreland basin shifted towards S, produced splay thrusts from the Himalayan Frontal Thrust-1 (HFT-1), which has been uplifting the Kimin and the older terraces.

    • Author Affiliations

       

      Goswami T K1 Bezbaruah D1 Soumyajit Mukherjee2 Sarmah R K1 Jabeed S1

      1. Department of Applied Geology, Dibrugarh University, Dibrugarh 786 004, India.
      2. Department of Earth Sciences, Indian Institute of Technology-Bombay, Powai, Mumbai 400 076, India.
    • Dates

       
  • Journal of Earth System Science | News

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