摘要
Clarkina postbitteri的首现不适合作为乐平统底界的定义,蓬莱滩剖面上6j的底界也不适合作为乐平统底界的全球界线层型剖面点(GSSP)。乐平统底界的定义应是Clarkina postbitteri-C.dukouensis连续的演化系列中C.dukouensis的首次出现,精确的位置在蓬莱滩剖面6k之底。
The first appearance (FAD) of Clarkina postbitteri is not suitable to be used as the definition of the basal boundary of the Lopingian Series in the Penglaitan section, nor is the base of bed 6j suitable to be used as the GSSP of the Lopingian. The basal boundary of the Lopingian should be defined by the FAD of Clarkina duk-ouensis in the Clarkina postbitteri-C. dukouensis evolutionary lineage. The precise position of the FAD of C. dukouensis in the Penglaitan section is at the base of the LPD114. 6-6k (GSSP).
出处
《地质论评》
CAS
CSCD
北大核心
2001年第2期113-118,T001,共7页
Geological Review
基金
国家自然科学基金(编号49272078)
关键词
乐平统
蓬莱滩剖面
广西
鲁平统
底界
二叠系
牙形刺
basal boundary
Lopingian
Clarkina postbitteri
Clarkina dukouensis
Penglaitan
Guangxi
