Ground-penetrating radar investigation along Pinjore Garden Fault: Implication toward identification of shallow subsurface deformation along active fault, NW Himalaya

摘要

A total of 24 m Ground Penetrating Radar (GPR) profiles acquired across the 6 m high Pinjore Garden Fault (PGF) scarp with 200 MHz antenna, yielded high-resolution subsurface image with penetration depth up to 6 m. Two strands of low-angle thrust faults (F1 and F2) were identified based on the prominent offset and warping in radar reflections. The F1 fault strand in the GPR profile was consistent with the fault identified in the trench excavated across the PGF. The GPR profile helped us to trace the fault strand of F1 at greater depth (>3 m) than that identified in the trench and also a new trace of fault branch F2 in the upper portion of the scarp. This suggested that multiple events have occurred along the PGF during the recent geologic past. With this attempt we suggest that the GPR technique can be a useful tool in mapping the shallow subsurface geometry and in locating the near-surface faults displacing young Quaternary sediments in the Himalayan foothill zone.