A Review of the Tectonic and Geological History of Eastern India in Terms of 'Plate Tectonics' Theory

The distinctive characteristics and independent evolution until Neogene times of the Bengal basin situated on the Indian plate and the Assam-Arakan basin situated on the Burmese plate, are described. The Indian plate during this period was simultaneously in the process of a northerly rafting movement according to the theory of plate tectonics. Arguments are put forth in support of the Assam-Arakan basin over-riding the Bengal basin towards west, and the Upper Assam shelf towards north-west simultaneously during Neogene times, as a result of the two plates coming together and consequent orogeny. The stabilist concept of geosynclinal theory for the formation of folded belts, according to which the Bengal basin and the Assam-Arakan basin have all along been considered by almost all previous workers to be forming a single geosyncline from their inception stage, has been questioned. The mobilist concepts involving plate tectonics theory have been introduced while broadly reviewing the tectonics and geological history of eastern India.