Petrotectonic Framework of the Siwalik Group of Shinghar Range with Special Reference to its Petrography
Abstract
Detailed petrological/petrotectonic account from Thatti Nasrati Shava-Shanawah area (Shinghar Range) of the Siwalik Group with reference to its petrotectonic framework has yet been published. It was therefore, important to carry out through petrological/petrotectonic studies in order to understand the nature, origin and condition of deposition of Siwaliks in this area.
In the past, it was generally considered that the Siwaliks were deposited by the mighty Siwalik River (ancestral Indus). But subsequent studies have indicated that Siwaliks show great lithological as well as petrographic diversity. Siwaliks of the different areas have been derived from different source of regions. Therefore, it was important to trace The sources of Siwalik sediments in this region and to relate them to an evolving petrotectonic framework.
Correlation of Siwaliks on the basis of gross lithological variation (sandstone/ shale ratio) has not proved very satisfactory. Similarly, faunal correlation is not always possible, because the distribution of the fossils is not uniform. So it was planned to correlate the Siwaliks of the area on the basis of petrographic studies.
Petrotectonic studies require a thorough understanding of the tectono-stratigraphic evolution of the hinterland as well as the nature of detritus shed by them both in time and space.
In order to understand the dynamics of the tectono-stratigraphic evolution of the source areas and the changing pattern of composition of the sediments, an integrated scenario have been presented.
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