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      https://www.ias.ac.in/article/fulltext/jess/121/03/0813-0822

    • Keywords

       

      Passive continental margins; effective elastic thickness; process-oriented approach; Konkan and Kerala basins; India.

    • Abstract

       

      Litho-stratigraphic variation of sedimentary units constructed from seismic sections and gravity anomaly in the Konkan and Kerala basins of the western continental margin of India (WCMI) have been used to model processes such as lithospheric rifting mechanism, its strength, and evolution of flank uplift topography that led to the present-day Western Ghats escarpment. Based on the process-oriented approach, two lithospheric models (necking and magmatic underplating) of evolution of the margin were tested. Both, necking and underplating models suggest an effective elastic thickness (Te) of 5 km and 10 km along Konkan and Kerala basins, respectively and a deep level of necking at 20 km at both basins. Model study suggests that the necking model better explains the observed gravity anomalies in the southern part of the WCMI. A synthesis of these results along with the previously published elastic thickness estimates along the WCMI suggests that a low-to-intermediate strength lithosphere and a deeper level of necking explains the observed flank-uplift opography of the Western Ghats. Process-oriented gravity modeling further suggests that the lateral variations in the lithospheric strength, though not very significant, exist from north to south within a distance of 600 km in the Konkan and Kerala basins along the WCMI at the time of rifting. A comparison with previous Te estimates from coherence analysis along the WCMI indicates that the lithospheric strength did not change appreciably since the time of rifting and it is low both onshore and offshore having a range of 5–15 km.

    • Author Affiliations

       

      Sheena V Dev1 M Radhakrishna1 2 Shyam Chand3 C Subrahmanyam4

      1. Department of Marine Geology and Geophysics, Cochin University of Science and Technology, Cochin 682 016, India.
      2. Present address: Department of Earth Sciences, IIT Bombay, Powai, Mumbai 400 076, India.
      3. Geological Survey of Norway (NGU), Postboks 6315, Sluppen, 7431 Trondheim, Norway.
      4. National Geophysical Research Institute, Hyderabad 500 007, India.
    • Dates

       
  • Journal of Earth System Science | News

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