The Cambridge History of India, Vol. I: Ancient India v1.c15.150

v1.c15.150

Thus we conclude a rapid survey of the historical and political geography of a vast region. The south and centre of India is structurally an island, whose steep brinks, the Western and Eastern Ghāts, are continued—beyond the coastal selvage and the strip of shallow water off shore—by renewed steep descents into the abysses of the Arabian sea and the Bay of Bengal, two miles deep. This great island has granitic foundations, although it is clothed in places with volcanic rocks. Its landward brinks are marked by mount Abu, the Arāvalli hills, the ridge of Delhi, and the long low eastward curve of hills ending at Rājmahāl, where the principal coal seams of India rest on the granitic base. The salient angles at Delhi and Rājmahāl are received, at a distance, by the great re-entering angles of the main framework of Asia, constituted by the brink of Irān beyond the Indus, the Himālayan brink of Tibet, and the mountains of the Burmese border. Between these rocky limits—salient on the Indian side and re-entering on the Asiatic side—extends a broad alluvial plain, two hundred miles in average breadth, and two thousand miles long, from the mouths of the Ganges northward to the foot of the mountains, then north-westward along that foot to the Punjab, and then south-westward to the mouths of the Indus.