Proposed GSSP for the base of Cambrian Stage 9,coinciding with the first appearance of Agnostotes orientalis, at Duibian, Zhejiang, China  

作　　者：Loren E. BABCOCK Gabriella BAGNOLI 

机构地区：[1]School of Earth Sciences, The Ohio State University [2]Department of Earth Sciences of Pisa University

出　　处：《Science China Earth Sciences》2009年第4期434-451,共18页中国科学（地球科学英文版）

基　　金：Supported by Chinese Academy of Sciences (Grant No. KZCX2-YW-122);the Ministry of Science and Technology of China (Grant Nos. 2006FY120300, 2006CB806400);National Natural Science Foundation of China (Grant Nos.40072003,40023002,40332018,40672023,40602002);the U.S. National Science Foundation (Grant No. EAR-0106883)

摘　　要：Exposed in natural outcrops near the Duibian Village, Jiangshan County, Zhejiang Province, China, the Duibian B section is proposed as the boundary stratotype for the base of an unnamed stage termed provisionally Cambrian Stage 9. The proposed position of the GSSP is 108.12 m above the base of the Huayansi Formation, at a horizon coinciding with the first appearance of the cosmopolitan agnostoid trilobite Agnostotes orientalis. This horizon coincides also with the first appearance of the cosmopoli-tan polymerid trilobite Irvingella angustilimbata. The section fulfills all the requirements for a GSSP, and the horizon can be constrained not only by the primary stratigraphic marker (A. orientalis) but also with secondary biostratigraphic, chemostratigraphic, and sequence-stratigraphic correlation tools. The first appearance of A. orientalis is one of the most readily recognizable levels in Cambrian, and can be correlated with precision to all paleocontinents.Exposed in natural outcrops near the Duibian Village, Jiangshan County, Zhejiang Province, China, the Duibian B section is proposed as the boundary stratotype for the base of an unnamed stage termed provisionally Cambrian Stage 9. The proposed position of the GSSP is 108.12 m above the base of the Huayansi Formation, at a horizon coinciding with the first appearance of the cosmopolitan agnostoid trilobite Agnostotes orientalis. This horizon coincides also with the first appearance of the cosmopolitan polymerid trilobite Irvingella angustilimbata. The section fulfills all the requirements for a GSSP, and the horizon can be constrained not only by the primary stratigraphic marker (A. orientalis) but also with secondary biostratigraphic, chemostratigraphic, and sequence-stratigraphic correlation tools. The first appearance of A. orientalis is one of the most readily recognizable levels in Cambrian, and can be correlated with precision to all paleocontinents.

关 键 词：CAMBRIAN GSSP FAD of Agnostotes ORIENTALIS China CHRONOSTRATIGRAPHY 

分 类 号：Q915[天文地球—古生物学与地层学]