Geology and Mineral Resources of Central and Northern China.

Abstract

The Three of China's “Five Holy Mountains”, the Tai-shan in Shantung, the Sung-shan in Honan, and the Hua-shan in Shensi are formed of the Archaean rocks or the Tai-shan complex, so called after the first named. The complex is composed chiefly of crystalline schists and gneisses, with intrusions of granites and of various dykes of a later age, probably pre-Cambrian. Another series of schists and gneisses, assigned to the early Proterozoic, occurs in a typical development in the Wu-tai-shan district of northern Shansi, after which it is named the Wu-tai system. Although an actual contact of the Tai-shan complex with the Wu-tai has not yet been ascertained, an unconformable relation can easily be inferred from their lithological and structural features.Widely distributed throughout China limestones occur in several thick beds, each attaining a thickness of some 1, 000 meters or more, in which many beautiful canyons are carved out. In Northern China are found two thick beds of limestone, the Nan-kou limestone (Sinian) and the Ki-chou limestone (Cambro-Ordovician), while in the Yangtze valley at least four beds may be enumerated, namely, the Tong-ying (Sinian), I-chang (Cambro-Ordovician), the Yang-hsin (upper Car-boniferous to Permian), and the Ta-yeh (Permian to Triassic). The Sinian lime-stones are underlain by a sequence of arenaceous and argillaceous beds, in which sedimentary hematite deposits of the Lungyen type are interbedded. In Central China upon the I-chang limestone lies a thick succession of limestone, shale, and sandstone, which falls within Silurian, Devonian, and lower Carboniferous, while in Northern China the Ki-chou limestone immediately underlies a coal-bearing formation of Permo-Carboniferous age, showing a hiatus of the first magnitude. Red formations, ranging from Triassic to Cretaceous in age, are characteristic features of basin areas, of which the Szechuan and the Shenpei basins are most important. The most remarkable superficial deposits are Pleistocene loess in Northern China and Pliocene red-earth with vermiculated mottling in Central China.There are four principal periods of igneous activities since Mesozoic time. The first period, very likely included in late Jurassic, is represented chiefly by granitic and andesitic rocks, the second, probably in early Cretaceous, by liparitic and andesitic eruptions, the third, in middle Cretaceous, by granodiorites, syenites, granites and porphyries, and the fourth, in early Tertiary, by basaltic flows.According to both productions and reserves hitherto estimated the following seven may be mentioned as principal mineral resources in China: coal, tungsten, antimony, tin, iron, gold and aluminous shales, of which the first three are of the world importance.The probable coal resources estimated by the Chinese Geological Survey in 1934 are 239, 100 million tons; of which according to geological age 60 per cent are Palaeozoic, 36 per cent Mesozoic, 4 per cent of unknown age; classified according to kinds 77 per cent bituminous coal, 19 per cent anthracite, 1 per cent lignite, 3 per cent unclassified; according to regions 89 per cent Northern China, 6 per cent Central, 1 per cent Southern, 4 per cent Northwestern. Our estimate is about 300, 000 million tons with Shansi alone, exceeding the above total by some 600 million tons.Iron are deposits may be classified into seven types, namely, sedimentary, hydrothermal, contact, magmatic, regional metamorphic, residual and detrital, the first three being most important. The total reserve of iron are has been estimated at about 323 million tons, of which 172 in Mimi tons are in Northern China, 117 million tons in the Central and remainig 34 million tons in the Southern. According to our estimation the total figures of reserves, each above 1 million tons, are about 368 million tons.