Comments on some important issues concerning the establishment of a GSSP for Cambrian Stage 5

Abstract

In order to help facilitate stratigraphic correlation between south China and Siberia, trilobite zones of Guizhou, China, and the Molodo River area, Siberia, need to be better coordinated. The Wuliu-Zengjiayan section is a strong candidate for the Global Standard Stratotype Section and Point for Cambrian Stage 5, and the Molodo River section provides important supplemental information that helps expand the precision of correlation on a global scale. The Kaili Formation in the Wuliu-Zengjiayan section contains three trilobite zones over an interval of 214.20 m. We propose that the Ovatoryctocara granulata Zone, as used in Siberia, replace the Ovatoryctocara Zone. Equivalent strata in Guizhou extend more than 150 m stratigraphically, from the Protoryctocephalus wuxunensis Zone to the Bathynotus kueichouensis–O. cf. O. granulata Assemblage Zone. We also propose that the traditional Kounamkites Zone be supplemented or replaced by the Oryctocephalus reticulatus Zone, which outside Siberia contains Oryctocephalus indicus.

Keywords::

• Oryctocephalus indicus
• Ovatoryctocara granulata
• Cambrian Stage 5
• GSSP
• China
• Siberia

Acknowledgements

The authors thank Dr F.A. Sundberg for revision in English and comment on the manuscript, and Profs T.P. Fletcher, L.E. Babcock, I.V. Korovnikov, S.C. Peng and P.D. Kruse for providing significant information for the manuscript. The authors also thank two reviewers for their valuable comments and helpful suggestions for revision. Paleontologists from the United States, F.A. Sundberg, L.B. McCollum, L.E. Babcock, Lin Jih-Pai and R. R. Gaines have cooperated with us for a long-term study of the boundary interval between Stage 4 and 5 of the Wuliu-Zengjiayan section (south China), and acknowledge their important contributions. This research is also a large group achievement. This research was supported partly by grants from the Major state Basic Research Development Program of China (973 program) (No. 2013CB835002), the National Science Foundation of China (NSFC, Nos. 41172005, 41330101), the Key Project of International Cooperation of Guizhou Science and Technology Department (Gui. No. 2010-7001), the Science Technology and Education Talent from Government of Guizhou Province (Gui. Sp.2011-37) and Fund of Stratigraphical Commission of China.