摘要
“国际地层表”依据菊石带建立起来的侏罗纪年代地层系统在全球海相侏罗系的划分和对比中有着广泛的应用,但却很难直接应用于非海相侏罗纪地层系统中。中国的侏罗系多属非海相,近年来我国地质工作者们不但将中国的海相侏罗系与全球侏罗纪年代地层系统进行了较合理的对比,发现了穿越海相三叠系-侏罗系界线的连续沉积的剖面,而且建立了非海相侏罗系的阶。
The Jurassic chronostratigraphic system set up on the basis of ammonites' zonations in “International Stratigraphic Chart” has been globally applied in subdividing and correlating the marine Jurassic, but it is very difficult to be directly applied in the nonmarine Jurassic. Most of the Jurassic in China are nonmarine and the marine Jurassic is only limited in the Qinghai-Xizang Plateau, southwestern Xinjiang, western Yunnan, Hongkong, central Guangdong, southern Yunnan, western Fujian, eastern Heilongjiang and probably in Taiwan. In the nonmarine Jurassic deposits, not only the nonmarine fossils are rich and colourful, but also the marine Jurassic rocks (e.g. the Middle and Upper Jurassic of Tanggula and Hohxil of northern Qinghai-Xizang Plateau) occasionally contain nonmarine unionids, nonmarine Jurassic deposits (e.g. the Lower Jurassic strata of Junggar Basin) sometimes yield marine or blackish bivalves of Waagenoperna , and even sometimes, the marine and nonmarine Jurassic fossil-bearing beds are alternated (e.g. the Jurassic in western Yunnan). In recent five years, Chinese geologists not only have done a good correlation of Tethyan and Boreal Jurassic with international Jurassic chronostratigraphic system and found a complete succession across the Triassic-Jurassic boundary in southern Tibet, but also established nonmarine Jurassic stages. In descend order, the Xiangxian Stage, Ziliujingian Stage, Xintiangouan Stage, Shaximiaoan Stage, Suiningian Stage and Penglaizhenian Stage represent the nonmarine Jurassic System of southern China; and the Badaowanian Stage, Sangonghean Stage, Xishanyaoan Stage, Toutunhean Stage, Tuchengzian Stage, uncertain Stage and Dabeigouan Stage represent the nonmarine Jurassic System of northern China. However, the age of each stage and the boundary between the stages are remained to be decided or testified by the marine fossils and isotopic and/or maganitic dating. Furthermore, the traditional Jurassic Jehol Group of Western Liaoning, northeastern China has been proved to be the middle and late Early Cretaceous Hauterivian to early Albian by the nomarine and marine correlation and isotopic dating as well.
出处
《地层学杂志》
CSCD
北大核心
2005年第2期124-129,共6页
Journal of Stratigraphy
基金
中国科学院知识创新工程项目 (KZCX2 -SW-129)
国家自然科学基金( No. 40 3 72 0 0 8)资助
关键词
中国
海相地层
非海相地层
侏罗系
年代地层学
国际地层表
China, marine strata, nonmarine strata, Jurassic, chronostratigraphy, International Stratigraphic Chart
