Abstract
Summary Explanations (Burton, 1970; Ridd, 1971) of the westerly origin of the sediments now forming the rocks of northwest Malaya, by deriving them from an India which once lay contiguously against Malaya are unacceptable because of the complexity of the movement of Gondwanic India and the known history of the Indian Ocean. The effects of the movement of India into Asia were such that the Tibetan part of the orogen which continues south through Yunnan into Malaya was distorted. Before the arrival of India the Tibetan massif also may have lain still further away from the rest of Asia and moved towards the Siberian Platform by sea-floor spreading in the Tethys, so that its erosion could have provided material now forming part of Malaya. The Tibetan–Yunnan–Malay orogen has a complex and probably sutured form.