Systems And Between Systems Of Cambrian Boundary Stratotype Candidate - Black Slip - Once Jiaya Profile Continues To Study

The selection of a Global Stratigraphic Section and Point (GSSP) for the boundary of the second series and the third series of the Cambrian is a long pending problem. In China, Zhao Yuanlong and Yuan Jinliang have proposed the Wuliu-Zengjiaya Section of the Kaili Formation as a leading candidate for this GSSP. Their proposal is based on the well-recognized FAD of Oryctocephalus indicus which has been demonstrated to define the base of the third series of the Cambrian. Paleontological and biostratigraphic study of the Wuliu-Zengjiaya Section has yielded a rich harvest which had attracted wide attention by many scientists.Zhao Yuanlong and Yuan Jinliang have proposed that the FAD of Oryctocephalus indicus is the best criterion for defining the base of the third series of the Cambrian. The Wuliu-Zengjiaya Section may provide the best straotype section for this critical time interval. Before the section may be considered as a GSSP, study of supplementary sections of the Kaili Formation and the distribution of trilobites within them, most importantly Redlichia, Bathynotus, Ovatoryctocara granulata, Oryctocephalus indicus is required. In this article a new section, the Jianshan section is described, measured, and the distributions of key fossils from the Jianshan section are described. These data from the Jianshan section are comprehensively analyzed. This study augments the strong case for the Wuliu-Zengjiaya section as a GSSP. Combined with other studies of the geochemistry, sequence stratigraphy, acritarch biostratigraphy, etc. this study of the distribution of trilobites confirms the same overall biostratigraphic, sedimentologic and geochemical patterns observed in the Wuliu-Zengjiaya section, thus strengthening the case for GSSP designation.Oryctocephalus indicus is widely distributed globally, and readily identifiable from clear diagnostic characteristics. Because its stratigraphic range is also brief, it may reliably be used as an index fossil. This research indicates that the FAD of Oryctocephalus indicus is a rather good marker of the beginning of Cambrian Stage 3.