Research Projects

Convergence of several northeast-trending across-strike crustal-scale lineaments and ridges (e.g. Delhi-Haridwar ridge: DHR, Faizabad ridge: FR and Munger-Saharsa ridge: MSR) with distinct differences in geophysical, geochemical and geochronological properties along the Himalayan arc, eventually leading to lateral variations in the ramp-flat-ramp setup of the Main Himalayan Thrust (MHT), rate of erosions and nature of strike-slip faulting within the foreland basin. The across-strike ridges are mostly underlain by the thick cover of Quaternary Ganga-Yamuna alluvial deposits south of the Main Frontal Thrust (MFT) extending northward and mostly composed of granitic and gneissic Precambrian basement rocks and are bounded by crustal-scale faults. Significant changes in the geomorphic markers observed in the foreland seem to be associated with the ongoing convergence of the buried ridges and can be included as useful proxies. To date, various land-based and airborne geophysical surveys coupled with geological studies have been carried out to constrain the position and dimension of the converging ridges beneath the alluvial deposits in the foreland basin. But no study, to our knowledge, is documented to investigate the nature of the buried faults associated with the reactivation processes of these ridges and to establish their connection with the geomorphic markers. In this research project, we propose to investigate the signatures of deformation associated with the reactivation of the ridges along the Himalayan arc using geomorphic markers. We will use the satellite image and gravity datasets to discern the location of the ridges followed by the controlled source seismological datasets to image the deformation. As the thickness of the sedimentary deposits are less (~2-3 km) above and across the ridges, the aforesaid techniques will be very suitable. We will further compute the throw of the disturbed sedimentary deposits to comment on the slip distribution of these faults. This study will further comment on the role of converging ridges on the seismicity and segmentation associated with the Himalayan arc.

Cross-Strike Ridges, Himalaya, Ganges-Yamuna, basin, Deformation, Seismic