摘要
我国贵州东部乌溜-曾家崖凯里组剖面作为世界早-中寒武世界线层型侯选剖面,产出良好保存的大型无脊椎动物化石(尤其是三叶虫)。因此,更加详细研究该剖面海洋疑源类的生物地层非常重要,将提供围绕界线的生物和环境变化的细微记录。乌溜-曾家崖剖面凯里组的疑源类划分两个组合,它们是凯里组0-52m的Leiomarginata si mplex-Fi mbriaglomerella membranacea组合和52-140m的Cristallinium cambriense-Heliosphaeridiumnodosum-Globosphaeridiumcerinum组合。140-214m仅有很少疑源类标本,可能因为凯里组上部以白云岩为主,不适宜有机壁微体化石的保存。距凯里组底部往上约52m处疑源类组合出现重大变化,无疑为解释沉积环境提供重要资料。两疑源类组合间界线,位于52.3-52.7m,此稍低于被三叶虫Oryctocephalusindicus首现所指示的全球寒武系第5阶潜在层型剖面界线。
As a proposed GSSP for Stage 5（＂Middle Cambrian＂ boundary）,the Wuliu-Zengjiaya section of the Kaili Formation,China,has yielded well-preserved macroinvertebrate fossils,especially trilobites.A more detailed study of acritarch biostratigraphy of the section is therefore necessary to provide an accurate record of biotic and environmental changes at the boundary.Acritarchs of the Kaili Formation in the Wuliu-Zengjiaya section can be recognized as two distinct assemblages：the Leiomarginata simplex-Fimbriaglomerella membranacea assemblage（0—52 m from the base of the Kaili Formation）;and the Cristallinium cambriense-Heliosphaeridium nodosum-Globosphaeri-dium cerinum assemblage（52—140 m）.From 140 m to 214 m,only a few acritarch specimens have been found.This is probably because the limestones that dominate the upper part of the Kaili Formation are not suitable for preserving organic-walled microfossils.A significant change of the acritarch assemblage occurs in a bed located approximately 52 m above the base of the Kaili Formation.Undoubtedly,this change in the acritarch assemblages provides important data for interpretation of the depositional environment.The boundary between the two acritarch assemblages（52.3—52.7 m）is slightly below the potential GSSP boundary of Stage 5 marked by the first appearance of the trilobite Oryctocephalus indicus.
出处
《古生物学报》
CAS
CSCD
北大核心
2010年第2期164-173,共10页
Acta Palaeontologica Sinica
基金
supported by the National Natural Science Foundationof China ( Grant Nos .40839910 , 40762001 and 40902003)
the Foundation of the Mobile Projectof Science and Technology of Guizhou Province(Grant No . Gui Ji 2007-4004)
the key project ofInternational cooperation of Guizhou Science andTechnology ( Gui . Co . G.[2008]700110])
the Major Basic Research Projects of MSTof China(2006CB806401)
关键词
疑源类
凯里组
早—中寒武世
乌溜-曾家崖剖面
贵州
Acritarchs Kaili Formation Early-Middle Cambrian Wuliu-Zengjiaya section Guizhou
