The Reseach On The Supplementary Sections Of The Wuliu Section Which Is The Potential Statotype Boundary Section Between The Second Series And The Third Series In Cambrian

The selection of the Global Stratigraphic Section and Point (GSSP) for the boundary which is between the second series and the third series in Cambrian is a long pending problem. Owing to the Cambrian trilobites which ever lived in the different protocontinents, it is not easy to divide the traditional Lower and Middle Cambrian. There are mainly three possibilities for global correlation at the traditional Lower and Middle Cambrian boundary interval at present, which merit scrutiny: (1) FAD of Oryctocephalus indicus; (2) FAD of Ovatoryctocara granulata; (3) FAD of Arthricocephalus chauveaui. Although each possibility is not perfect, FAD of Oryctocephalus indicus is a leading FAD in them, which has been acceptted by many palaeontologists and stratigraphers.In China ZhaoYuanlong and Yuan Jinliang study on the FAD of Oryctocephalus indicus for defining the base of the third series in Cambrian and have yielded a rich harvest which had attracted wide attention by many scientists. Meanwhile Zhao researches on the Wuliu section, standing as a leading candidate for a GSSP. Under the background, it is necessary to systematically investigate the supplementary sections of the Wuliu section and the distribution of the Cambrian trilobites in Guizhou Province, such as Redlichia, Bathynotus, Ovatoryctocara granulata, Oryctocephalus indicus. These studies are helpful to make the Wuliu section become a GSSP. In this article the two new sections are measured, the fossils from which are identified. And the data from the five measured sections are comprehensively analyzed. Through the researches, it is clearly that Oryctocephalus indicus is a rather good FAD.