Geological Signatures of Tectonic Instability along the North Cambay Basin during the Late Holocene Period, North Gujara
- PDF / 1,159,278 Bytes
- 7 Pages / 595 x 842 pts (A4) Page_size
- 117 Downloads / 193 Views
Geological Signatures of Tectonic Instability along the North Cambay Basin during the Late Holocene Period, North Gujarat, India Archana Das* and Tarun Solanki Active Tectonics Group, Institute of Seismological Research, Gandhinagar - 382 009, India *E-mail: [email protected]
ABSTRACT In the present study, the tectono-geomorphic attributes of the northern part of the Cambay basin, Western India, which has recently witnessed a surge in seismic activity has been investigated. The anomalies in the drainage network (morphometry) along with the sedimentological character of the drainages with OSL chronology was used to unravel the abrupt aggradation and incision processes during the late Holocene period. The analysis reveals two major lineaments i.e. NE-SW, which are related to the transfer faults and NW-SE lineaments, related to the listric/normal faults prevalent in the northern Cambay region. The NW-SE trend exhibited the first order streams, which hints the ongoing tectonic activity along the buried structural elements/faults. The valley fill sediments were incised during the late Holocene period i.e. < 3 ka, which is ascribed to the tectonic activity along the buried structure/ faults in the Tharad-Sanchor block of the north Cambay basin. The present study is the first attempt to characterize the tectonic activity along the Tharad-Sanchor block of the north Cambay basin using geomorphometry and optical dating. INTRODUCTION The drainage networks in tectonically active regions respond differently to active structures such as folding and faulting (Lave and Avouc 2001; Whipple et al., 2013). The relationship between the landform development and the tectonics has often been investigated, as it helps to understand the active tectonic stresses prevalent in the region. In this regards, morphostructural analysis has been conventionally employed as a first hand tool to explore the relationship between the geometry of the fluvial network and buried faults (Centamore et al., 1996; Raj, 2012; Prizomwala, 2018). Morphometric indices have been successfully used to demarcate the relative variations in an ongoing deformation in regions affected by active faults (Azor et al., 2002; Prizomwala et al., 2016) and in the identification of buried structures in unexplored regions (Bull and Mcfadden, 1977; El Hamdouni et al., 2008; Raj, 2012; Solanki et al., 2018). Several studies have suggested that offsetting in channels (OC), deflected streams (DS), aligned drainages (AD) and displaced terraces, provide useful information about the presence of underlying structures (Gaudemer et al., 1989; Lin et al., 2002; Raj, 2007; Prizomwala, 2018). However, the geomorphic processes are also controlled by topographic, climatic, and lithological factors that must be taken into account when tectonically oriented conclusions are derived (Jackson and Leeder, 1994; Schumm et al., 2000; Burbank and Anderson, 2000; Keller and Pinter, 2002). The Gujarat region located in the westernmost part of India, covering an area of around 1,96,000 km2 is seismically
Data Loading...
