Origin of Quaternary Basin of Sohna Valley, Southeastern Haryana

The NNE-SSW trending Sohna valley in southeastern Haryana, ranges in elevation from nearly 200 m in the southwest to about 190 m in the northeast. An isolated hillock occurs as an inselberg at Indri with an altitude of 270 m. The bedrock occurs below the present day rn.s.1. around the inselberg. The area represents an elevated land subjected to normal denudation up to Pleistocene as no sedimentation has been recorded over the Neoproterozoic rocks. Analysis of the borehole data suggests that the deepening of the bedrock around Indri inselberg was caused by a combination of subsidence due to reactivation of N-S and NNE-SSW trending faults and denudation in early Pleistocene which continued into Holocene.