Abstract

Ground-penetrating radar (GPR) investigations were conducted along the western part of the seismically active Kachchh Mainland Fault (KMF) of the Kachchh Rift Basin (KRB). The strike of the fault changes from NNW to W in the study area from Lakhpat in the west to Mundhan anticline in the east. The change in the strike is due to oblique-slip movement along various NNE-striking transverse faults cross-cutting the KMF. The GPR studies were conducted to precisely locate the surface position of the KMF and to understand its shallow subsurface geometry. The subsurface Interface Radar-20 (SIR20) GPR system of GSSI Inc., USA along with 200 MHz frequency antenna were used. We infer the KMF to be a north-dipping normal to a near-vertical fault. The fault changes its attitude at places being affected by various transverse faults. The GPR data, along with the field evidence, such as fault zone deformational features