Report of the restudy of the defined global stratotype of the base of the Silurian System  

作　　者：Jiayu Rong Michael Melchin S. Henry Williams Tatyana N. Koren Jacques Verniers 

机构地区：[1]SKL, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 210008 Nanjing, PRC [2]Department of Geology, St. Francis Xavier University, Antigonish, NS, B2G 2W5 Canada [3]Petro-Canada Oil and Gas, 150 - 6th Avenue SW, Calgary AB, T2P 3E3 Canada [4]All Russian Geological Research Insfitute-VSEGEI, Sredny pr. 74, 199026, St. Petersburg, Russia [5]Research Unit Palaeontology, Ghent University, Krijgslaan 281/S 8, 2000, Ghent, Belgium

出　　处：《Episodes》2008年第3期315-318,共4页地质幕（英文版）

摘　　要：The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.

关 键 词：全球层形 志留纪 地质学 研究项目 

分 类 号：P54[天文地球—构造地质学]