Active Tectonics Astride Katrol Hill Zone, Kachchh, Western India

Katrol hills occupy the central Kachchh mainland and belong to an area of active tectonism. This area is one of the few seismically and tectonically active areas outside the Himalayan mountain belt. A longitudinal fault flanks the hills to the north (Katrol Hill Fault Scarp) and morphotectonic analysis along this hill range has confirmed that the area has undergone differential tectonic uplift. Various geomorphological criteria viz., mountain front sinuosity, faceting, facet dissection percentage of 62 fronts of two sub-areas, valley floor to valIey height ratios and concavity indices of the streams flowing due north and south of Katrol hills reflect the amount of influence of tectonic activity during Quaternary times. Pattern of seismicity in the area reveals that all the known earthquakes in this region fall more or less in the Katrol Hill Zone running E-W for about 100 km. The warping of Quaternary rocks further furnishes field evidence of tectonic activity in post Upper Pleistocene times. Morphometric analysis along with seismic pattern and geological evidences indicate that the Katrol Hill Zone continues to be tectonically active.