Tectonics of Kachchh basin based on field structural geological studies and paleostress analysis in Bhuj, Gujarat, India

Abstract

The Mesozoic Kachchh basin is one of the most active tectonic and seismological regions in India in NW Gujarat. The tectonic setting here comprises of many regional faults and movement along these faults frequently result in seismicity. This thesis comprises of understanding the formation of some of these faults and the paleostress analysis along those fault planes. The stress analyses provided paleostress axes orientations from the selected areas of study around the Bhuj city. The fault systems observed in this study are used for performing paleostress analysis. The results of this analysis shows that the terrain is primarily under extensional stress and thus the rocks are faulted normally. A total number of 94 data points were analyzed from 5 different sites. The direction of principle stress axes for studied sites is ~NE for maximum stress axis and ~SW for minimum stress axis. The results from both programs used for analysis are similar and show similar trend. The direction of stress axes and that of extension obtained from the programs match the overall trend in Kachchh Rift Basin (KRB) and thus confirm that the findings of the study are compatible with the surroundings.