摘要
一、前言一个半世纪前,两位英国先驱地质学家A.Sedgwick和R.Murchison(1835)分别创立了寒武系(Cambrian System)和志留系(Silurian System)两个系级单元。4年后,Murchison(1839)的“志留系”一书正式出版,距今恰好150年。为此,国际志留系分会和英国的有关学会在英国召开国际志留系大会,并组织野外旅行,考察英格兰和威尔士志留纪地层剖面。当年Murchison创立志留系的这些重要剖面,今日已成为国际志留系的统阶层型;Murchison在创立志留系后,直下威尔士西南角Pembroke郡的Marloos。
Researches on the Silurian geology in China are reviewed in some detail in this paper, with four stages recognized as 1)1882—1923; 2)1924—1948; 3) 1949—1966; and 4) 1967—present. The situ ation of researches has been greatly improved during the last stage through investigations of Silurian rocks in various parts of China and publication of a great number of papers in stratigraphy, palaeontology, palaeogeography, and so on.During the Silurian time, China was composed mainly of four plates, namely, North China (Sino-Korean) Plate, South China Plate, Tarim Plate and Xizang (Tibet) Plate (Text-fig. 1), with the occurrence of some relatively small blocks distributed among these plates or extensions of the Siberian and Kazakhstan Plates.The Silurian geology of the Yangtze Platform which occupied most part of the South China Plate is far better known than that of any other comparably large-sized region of China. The Silurian rocks consist mainly of three parts: with lower part containing shales (Lungmachi Formation), middle part shelly carbonates (such as Lojoping or Shihniulan Formation), and upper part shelly clastic sediments with marine red beds (such as Shamao or Hanchiatien Formation). These divisions were correlated with the Llandovery, Wenlock, and Ludlow Series respectively by Sun (1938), Yin (1949, 1966) and Mu (1964). Based on the new data, it should be pointed out that the fossiliferous beds of the Silurian younger than the Llandovery Series are probably absent throughtout the Yangtze Platform, except in eastern Yunnan and western Sichuan where the Ludlow and Pridoli Series are well developed, whereas the Llandovery and Wenlock Series are wholly missing. Stomatograptus sinensis, Monograptus spiralis and Pterognathodus celloni occur in association with brachiopods (Salopinella, Xinanospirifer, Nalivkinia magna and others), trilobites (Coronocephalus, Coronaspis and others), nautiloids (Sichuanoceras fauna), chitinozoan (Angochitina longicollis)and others in the uppermost part of the Silurian rocks in most part of the region, indicating the latest Telychian age.The brachiopod Molongia Fauna has been known to occur in eastern Yunnan and western Sichuan, South China, and central Inner Mongolia, Jiin, North China, whereas the brachiopod Tuvaclla Fauna has been known to be present in northeastern Xinjiang, Lesser Khingan, Heilongjiang, south peripheral belt of the Siberian Plate and other regions of Soviet Union, indicating that they were probably separated during the Ludlow and Pridoli times.The Silurian rocks mainly with platform facies in Tibet have been studied by Lin and Qiu (1983) and Mu and Chen (1984); recently biostratigraphic conodont zonation of Llandovery to Pridoli has been established by Qiu (1985). There were several plates within the territory of Xinjiang, NW. China, including the Tarim Plate, part of the Kazakhstan Plate and part of the Siberian Plate; and there have been encountered Llandovery and Ludlow graptolites, Llandovery conodonts and Llandovery to Pridoli brachiopods (Chen et al., in press).Brief consideration is given for future work of the Silurian geology in China including Silurian stratigraphy, palaeontology, palaeogeography, palaeobiogeography, palaeoecology, tectonics, and sedimentology.
出处
《古生物学报》
CAS
CSCD
北大核心
1990年第4期385-401,共17页
Acta Palaeontologica Sinica
基金
国家自然科学基金委员会4870090项资助
为中英志留系研究项目阶段成果之五
