Himalaya, the Northern frontier of east Gondwanaland

Abstract

The Himalayan province, which represents the northern platform of the Peninsular India belonging to East Gondwanaland, was strongly affected by Pan-African diastrophism 500±25 Ma ago. This brought to an end the protracted Purana cycle of sedimentation throughout the Peninsular India and the Lesser Himalaya and interrupted basin-filling in its northern Tethyan domain. But the sea returned in the Early Permian along a narrow depression formed due to rifting of the Himalayan crust in what is today the southern Lesser Himalaya. In the rift valley was deposited tillites by glaciers of the Gondwana continent under grip of refrigeration. Along with the glacigene conglomerates were emplaced diamictites generated by submarine slides triggered, presumably, by earthquakes originating from faults delimiting the rift. The diamictities are admixed with lava, agglomerate and tuff, indicating widespread volcanism in the rift valley. The rifting culminated in the breaking away of the Tibetan part of the Himalaya in the Late Permian and formation of Neotethys between the Gondwanaland and the Cimmerian microcontinent embodying Tibet, Iran and Turkey. Rivers of the northern Peninsular India flowed in the northerly directions since the Middle Proterozoic through Early Eocene. In the Late Eocene there was a drastic drainage reversal to south and southeast when the Himalaya emerged in the northern front of the Gondwanaland.