侏罗系-白垩系界线和我国东北地区下白垩统陆相地层相关问题的探讨  

THE CONTINENTAL JURASSIC-CRETACEOUS BOUNDARY IN CHINA

作　　者：周忠和[1] 贺怀宇[2] 汪筱林[1] 

机构地区：[1]中国科学院古脊椎动物与古人类研究所脊椎动物进化系统学重点实验室 [2]中国科学院地质与地球物理研究所

出　　处：《古生物学报》2009年第3期541-555,共15页Acta Palaeontologica Sinica

基　　金：国家重点基础研究发展规划项目(2006CB806400);创新研究群体基金项目(40121202;40221402)联合资助

摘　　要：文中介绍目前国际侏罗系-白垩系界线研究的进展以及我国东北地区下白垩统和相关陆相地层的研究现状。针对目前国内陆相侏罗系-白垩系界线研究中存在的争议,澄清一些概念,提出我国相关陆相地层的研究需结合古生物学、同位素年代学、古地磁学等多学科的结果。近年来的研究表明,这些综合性的工作和最新国际地质年代表的结果并不矛盾。最新的国际地质年代表中提出的侏罗系-白垩系界线的年龄(145.5±4Ma)得到国内外学者的广泛支持,相比之下,一些学者提出的侏罗系-白垩系界线年龄为135Ma或125Ma的观点还缺乏地层学和同位素年代学的证据。近年来年代地层学研究的进展为我国东北地区下白垩统精确国际对比提供了重要证据。东北地区陆相早白垩世沉积中脊椎动物化石的发现以及多数无脊椎动物和植物化石研究的结果表明,生物地层学的证据与年代学和古地磁学证据基本吻合。文中还通过一些实例,探讨在生物地层学(特别是脊椎动物地层学)研究中,重视生物系统发育学研究的重要性,即应当重视"谱系发育关系相近属种的对比",从而可以有效避免采用化石确定地层年代过程的一些误区。文中尚论及白垩系Aptian阶的底界年龄以及国际地质年代表中下白垩统一些阶的年限确定的意义。We here briefly review the recent progress in the study on the global Jurassic-Cretaceous boundary and its implications for the continental J-K boundary in China,particularly in northeastern China.The proposals of 135Ma,125Ma or even younger age for the Chinese J-K boundary by some workers are dismissed based on a comprehensive analysis of paleontological,geochronologic,and paleogeomagnetic studies of the Lower Cretaceous stratigraphy in northeastern China,which is rather consistent with the proposal of 145.5±4Ma for the J-K boundary.The conclusion of middle Early Cretaceous age for the birds-and feathered dinosaurs-bearing deposits,i.e.,the Jehol Group,in China is supported by extensive and compelling evidence of biostratigraphic,geochronologic,and paleogeomagnetic studies in the region.Vertebrate biostratigraphy of the Lower Cretaceous in northeastern China is summarized based on most recent discoveries of fossils such as birds,dinosaurs,pterosaurs,and mammals,many groups of which show a global distribution with biostratigraphic significance.We also emphasize the importance of the principle of ＂Strict Phylogenetic Closeness＂ of fossil taxa in application for biostratigraphic correlations.Finally,we discuss the controversy over the age of M0r（the bottom of Aptian） in view of recent geochronological and paleogeomagnetic studies of the Early Cretaceous volcanics in northeastern China.

关 键 词：年代学 古地磁学 系统发育 侏罗系-白垩系界线 中国 

分 类 号：Q911[天文地球—古生物学与地层学]