THE DEVONIAN SYSTEM OF CHINA
Yang Shipu (Wuhan Geologic College)Pan Jiang, Hou Hongfei (Chinese Academy of Geological Sciences)
The Devonian System of China is chiefly distributed in the Tianshan-Hingan Geosyncline of North China, the Yangzi Paraplatform of South China and in the geosyncline areas of West China. In the central region, Devonian formations are entirely absent in Sino-Korean Paraplatform and Tarim Platform, but along the border of the Tarim Basin and the south and north slopes of Qilianshan, they are represented by continental sequences rich in vertebrate and plant fossils. According to the difference in depositional conditions the Devcnian is divisible into 8 regions: Ⅰ. JungarHingan, Ⅱ. South Tianshan, Ⅲ. Qilianshan, Ⅳ. Longmenshan-Qinling, Ⅴ. South China, Ⅵ. Southeastern China, Ⅶ. West Sichuan-North Xizang and Ⅷ. Himalaya-West Yunnan Region.On the bases of both lithostratic and biostratic characteristics 5 principal types may be further differentiated : 1, Hingan type (Eugeosynclinal facies); 2, Baoxing type (Miogeosynclinal facies); 3, Xiangzhou type (Platformal near-shore facies); 4, Nandan type (Ptformal off-shore facies); 5, Cuifengshantype (Continental facies).The Devonian of South China being known by its various depositional types, has a well defined stratotype. Studies on the Devonian biota have contributed greatly to the understanding of the Devonian of this region over a period of 20 years Beginning from 1959 the Devonian of South China has been classified by the Chinense geologists into 8 stages as follows: Upper Devonian——Hsikuangshanian, She tienchiaonian; Middle Devonian——Tungkanglingian, Napiaonian (Yintangian); Lower Devonian——Tangdingian (Sipainian), Yukiangian, Nakaolingian, Lianhuashanian.The Devonian of the geosyclinal regions of West China is characterized by a faunizone of graptolites and tentaculites. Having been influenced by polygene tectonic movements, the rocks were locally deeply metamorphosed. The Devonian biota of the Junggar-Hingan Region is essentially an endemic one, but it is associated with a few European and North American elements. Marine pyroclastics are the principal rocks. The continental Devonian of China is unique esspecially in the light of its vertobrate contents. The red sandstone of the Early Devonian is well developed, and intercalated with argillaceous limestone and mudstone. This sequence is rich in East Asiatic faunal elements including both agnathans and fishes, such as Galeaspis, Polybranchiaspis, Yunnanolepis, etc. which form a typical endemic fauna. In the Middle Devonian, the principal rocks consist of red and light colour quartzose sandstone and mudstone in Southeastern China, with some red sandstone in both South and North China, while the fauna and flora are of cosmopolitan character. The vertebrate taxa appeared in geological ages which differ from those of similar taxa in other regiona of the world, for example, Asterolepis and Bothriolepis.This paper was read in the International Sysmposium on the Devonian System 1978 (P. A. D. D. 78), held in Bristol, Britain.