Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/87

Rh that the west coast of India adjoined the east coast of Madagascar. Both coasts consist of a strikingly straight fracture of a plateau of gneiss, which suggests that they could, after the formation of the rift, have slid along one another in a similar manner to Grinnell Land and Greenland. Basalt occurs on both sides at the northern end of the fracture, which on both coasts is about 10° of latitude in length. The basalt sheets of the Deccan, beginning at latitude 16° N. in India, were formed in the early Tertiary, and therefore may be brought into causal connection with the detachment. In Madagascar the most northerly portion of the island is completely built of two different ancient basalts, the date or origin of which has apparently not yet been ascertained.

The enormous folds of the Himalayan mountain system, formed essentially in the Tertiary, denote a compression of a considerable portion of the earth’s crust, by the reconstruction of which the outlines of Asia become very much altered. The whole of Eastern Asia from Tibet and Mongolia to Lake Baikal, and possibly even to the Bering Straits, probably took part in the compression. Recent work has shown that the processes of folding were by no means confined only to the Himalayas, but, for example, Eocene beds have been folded up to an altitude of 5600 m. above sea-level in Peter the Great Mountains, and great overthrusts have been produced in the Tienshan System. But even where such folding phenomena are absent, the recent elevation of undisturbed country is in just as close connection with this process of folding. The huge