三叠纪年代地层与中国建阶  

Triassic Chronostratigraphy and Chinese Stages

作　　者：童金南[1] 殷鸿福[1] 

机构地区：[1]中国地质大学生物地质与环境地质国家重点实验室,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2015年第2期189-197,共9页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(No.41272372);国土资源大调查项目专题(No.1212011120116)

摘　　要：国际地层委员会三叠系分会(Subcommission on Triassic Stratigraphy,简称STS)成立后的第一件工作就是建立全球统一的三叠纪年代地层划分方案.以国际地质对比规划项目IGCP-4(特提斯地区的三叠系)所取得的研究成果为基础,经过STS专家的深入研讨,采用投票表决的方式于1991年确定了将三叠系划分为3统7阶的国际年代地层格架.随后的焦点集中于各阶界线层型剖面和点位(Global Stratotype Section and Point,简称GSSP)的选定工作.但时至今日只确定了3个阶的GSSP,而且只有三叠系底界,即印度阶底界的GSSP获得的研究最多,且应用广泛;另外2个阶(拉丁阶和卡尼阶)底界的GSSP仍以传统的菊石作为首选定义标志,其推广可应用性还待实践检验.其他4个阶的界线层型选定工作正在推进中,但都存在一些困难,其中尤以奥伦尼克阶界线层型的选定工作面临重大挑战.鉴于国际年代地层研究工作所面临的困境,全国地层委员会组织专家于2000年提出了中国的年代地层划分和建阶方案,并在全国范围开展研究和推广应用.由于三叠纪时期中国处于从海向陆的重要转折时期,海、陆相地层在中国都有广泛发育,因此提出了海、陆相两套中国三叠纪年代地层划分和建阶方案.经过十多年的建阶研究和应用实践,中国三叠纪年代地层建阶方案逐步得以改进和完善,促进了中国三叠纪地层规范化研究,为相关科学研究和实践应用奠定了基础,也推动了国际相关领域的科学研究.Construction of a global scheme of Triassic time scale was the first key task of the Subcommission on Triassic Stratigraphy（STS）since its foundation in 1971.Based upon the scheme of Triassic time scale resulted from the research of the International Geological Correlation Programme IGCP-4（Triassic of the Tethys Realm）,the STS members made an in-depth discussion and finally voted in 1991 for the scheme that the Triassic is divided into 3series and 7stages.STS has been working on the selection of the Global Stratotype Section and Point（GSSP）of the stage boundary.However,only 3GSSPs have been decided in the Triassic up to the present,and among them only the base of the Triassic,i.e.,the base of the Induan Stage,has been well studied and widely applied to various areas over the world,whereas the other 2GSSPs,i.e.,the bases of the Ladinian and Carnian stages,are defined through the traditional ammonoid indexes and their extension and application need to be confirmed by further investigation.The selections on the stratotypes of the remaining 4stages have been in progress but they are challenged by some issues,especially the decision of the Induan-Olenekian boundary stratotype.Considering the difficulties in the construction of the International Chronostratigraphic Chart,the Stratigraphic Commission of China proposed a Chinese Chronostratigraphic Chart in 2000 to meet the demands of the geological survey and researches in China.Since the Triassic was the turning period from marine to terrestrial facies in the geological history and both marine and terrestrial Triassic strata are widespread in China,two schemes of Chinese Triassic chronostratigraphic division corresponding respectively to the marine and terrestrial facies and related Chinese stages have been suggested.After ten years of study and application,the schemes for the Chinese Triassic chronostratigraphic divisions and stages have been improved and refined,which promotes the standardizationof the Triassic studies in China,and facilitates the global T

关 键 词：三叠系 年代地层 界线层型 中国建阶 研究进展 地层学 

分 类 号：P534.63[天文地球—第四纪地质学]