Title: A SUPPLEMENTAL PRECAMBRIAN-CAMBRIAN BOUNDARY GLOBAL STRATOTYPE SECTION IN SW CHINA
Abstract: Since 1992, the siliciclastic Fortune Head section(southeastern Newfoundland, Canada) and the base of the Trichophycus pedium trace fossil zone have together served as the Precambrian Cambrian(PreC C) boundary global stratotype section and point(GSSP). However, the fact that the Fortune Head section consists mainly of siliciclastic rocks makes it difficult to correlate this section with boundary sections consisting mainly of carbonate rocks, which contain abundant small shelly fossils(SSFs) and can also be correlated using stable carbon isotope data. We propose that a predominantly carbonate section near the town of Dahai, eastern Yunnan Province, southwestern China, be designated a supplementary stratotype for the PreC C boundary GSSP, for the following reasons:(1) the Dahai section is continuous, consisting of the Neoproterozoic Baiyanshao and Daibu members conformably overlain by the Early Cambrian Zhongyicun and Dahai members and Shiyantou Formation; (2) the Early Cambrian units contain abundant SSFs representing four assemblage zones; (3) the Dahai section can be correlated with numerous other sections using stable C isotopic chemostratigraphy; (4) the famous Meishucun section, located not far from Dahai, contains both abundant SSFs and trace fossils and can be readily correlated with the SSF rich Dahai section. We further propose that the base of the Cambrian System be placed at the base of the first SSF assemblage zone(the Anabarites Protohertzina Zone), which in the Dahai section coincides with the base of Bed 11.
Publication Year: 2002
Publication Date: 2002-01-01
Language: en
Type: article
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Cited By Count: 22
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