GEOLOGY. Little is known of the geology of the greater part of Asia. Certain limited regions, such as India, have been studied in detail, hut our knowledge of the greater part of the continent has been derived from piecing together the reports of explorers. The great mountain systems consist principally of granites, gneisses, sehists, and al lied rocks, with, in many cases, the older strati fied rocks lying on their flanks. This is the ease with the Himalayas, whose uplift is believed to hase occurred as late as Tertiary times and with the Tian-shan, Altai, Stanovoi, and the Kuenlun ranges. The Ural Mountains, also, have a metamorphic nucleus. In the Caucasus, in Armenia, the Vindliya range of India, and in Persia. are extinct volcanoes, which have con tributed lava and ashes to the building of the mountains, while in the peninsula of Kamchatka, the Japanese Islands, and the East Indies are many active cones. Indeed. this region on the east and southeast of Asia is cite of the largest and most active volcanic regions on the earth.
The vast plain of Siberia is floored in succes sion from cast to west with stratified beds, rang ing from the oldest to the youngest, with large areas of eruptive and metamorphic rocks. The
Desert of Gobi and the Plateau of Tibet are, except for the mountain ranges. floored with Tertiary and Quarternary beds. In China, how ever, the rocks are much older, consisting of Carboniferous and Jurassic beds, which in the low coast regions underlie great beds of loess with which much of the level country is covered. The western plateaus in Afghanistan, Baluchis tan, Persia, and Asia Minor arc in the main cov ered with Tertiary and Quarte•mtry rocks, but in Arabia a large part of the plateau is floored with Jurassic beds. The great depression of northern India, south of the Himalayas, is a Tertiar3 deposit and a part of a large land area that once extended across the Indian Ocean to South Africa. The peninsula itself is composed of metamorphic and igneous rocks, with here and there areas of Paleozoic beds. Glaciers are found chiefly in the high mountain regions of the Tian-shan, Kuenlun, and Himalaya ranges, in the Tibetan highland, and in the Caucasus. No glaciers are found near the Arctic coast, owing to the deficient precipitation. See Geology, under INDIA; CIIINESE EMPIRE.