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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/126/06/0083

    • Keywords

       

      Himalayan tectonics; himalayan frontal thrust (HFT); main boundary thrust (MBT); fault related folds.

    • Abstract

       

      In the NW Sub-Himalayan frontal thrust belt in India, seismic interpretation of subsurface geometry of the Kangra and Dehradun re-entrant mismatch with the previously proposed models. These procedures lack direct quantitative measurement on the seismic profile required for subsurface structural architecture. Here we use a predictive angular function for establishing quantitative geometric relationships between fault and fold shapes with ‘Distance–displacement method’ (D–d method). It is a prognostic straightforward mechanism to probe the possible structural network from a seismic profile. Two seismic profiles Kangra-2 and Kangra-4 of Kangra re-entrant, Himachal Pradesh (India), are investigated for the fault-related folds associated with the Balh and Paror anticlines. For Paror anticline, the final cut-off angle β=35∘ was obtained by transforming the seismic time profile into depth profile to corroborate the interpreted structures. Also, the estimated shortening along the Jawalamukhi Thrust and Jhor Fault, lying between the Himalayan Frontal Thrust (HFT) and the Main Boundary Thrust (MBT) in the frontal fold-thrust belt, were found to be 6.06 and 0.25 km, respectively. Lastly, the geometric method of fold-fault relationship has been exercised to document the existence of a fault-bend fold above the Himalayan Frontal Thrust (HFT). Measurement of shortening along the fault plane is employed as an ancillary tool to prove the multi-bending geometry of the blind thrust of the Dehradun re-entrant.

    • Author Affiliations

       

      Joyjit Dey1 R Jayangonda Perumal2 Subham Sarkar3 Anamitra Bhowmik4

      1. Indian Institute of Technology Kharagpur, Kharagpur 721 302, India.
      2. Wadia Institute of Himalayan Geology, Dehradun, Uttarakhand 248 001, India.
      3. Presidency University, Kolkata 700 073, India.
      4. Jadavpur University, Jadavpur, Kolkata 700 032, India.
    • Dates

       
  • Journal of Earth System Science | News

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