Sedimentation and Tectonics of the Siwalik Group of the Trans-Indus Salt Range, Northwestern Pakistan
Abstract
Sediment accumulation rates calculated for flluviatile sediments of the Trans-Indus Salt Range in northwestern Pakistan are generally higher than those of the Potwar Plateau. This indicates more rapid subsidence of the Trans-Indus area compared to the eastern Potwar Plateau area, as well as a continued supply of detrital material. The entire stratigraphic sequence, which covers a time span of 12.0-0.5 Ma, is conformable, suggesting that the only tectonic activity in this area over this period consisted of gradual subsidence of the depocenter. However, Siwalik sedimentation ceased at about 500,000 BP when the Trans-lndus region was uplifted during Pleistocene phase of the Himalayan orogeny. The uplifted terraces of recent alluvial deposits show that uplift is still an active process in this area.
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