Chapter 1 - Concept of Indian Shield: Evolution and Reconstitution

Abstract

Traditionally, the triangular-shaped Peninsular India is described as the Indian Shield. Geological information, however, suggests that the Precambrian terrane of Peninsular India once constituted a part of much larger crustal block described as the ‘Greater India’. The pristine size of the Indian Shield is difficult to ascertain, but surely, it extended considerably in the north, as also in the southeast into Antarctica and in the southwest into Madagascar and Seychelles. The geological and geophysical data indicate that much of the Himalayan edifice is made of components sliced off from the Indian Shield during the late Cenozoic. Apart from that, the slicing of the Indian Shield due to the separation of Antarctica, Madagascar, and Seychelles during the late Phanerozoic helped in pruning the pristine size of the Indian Shield to that of Indian Subcontinent. Further, the process of fragmentation of the pristine Indian Shield into the shape and size of Indian Subcontinent during the different Phanerozoic (post-Precambrian) events has also grossly altered the geological, geomorphic, and geophysical characters of the terrain known to us as Indian Subcontinent.