RECENT QUARRYING ACROSS THE PROPOSED GSSP FOR STAGE 5 (CAMBRIAN) AT THE WULIU-ZENGJIAYAN SECTION,GUIZHOU,CHINA
Frederick A. SUNDBERG~ 1) ,ZHAO Yuan-long~ 2) ,YUAN Jin-liang~ 3) and LIN Jih-pai~ 3) 4) 1) Show Low High School,500 W. Old Linden Rd.,Show Low,AZ 85901,USA;2) College of Resource and Environment Engineering,Guizhou University,Guiyang 550003;3) Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008;4) Department of Geology and Geophysics,Yale University,New Haven,CT 06511,USA
Quarrying across a potential GSSP of the Cambrian Stage 5/Series 3 boundary indicates a significant change in trilobite and inarticulate brachiopod faunas. The quarry spans approximately 4.5 m across the potential boundary,which is the FAD of Oryctocephalus indicus in the Wuliu-Zengjiayan section. Detailed collections show that the faunas of the Ovatoryctocara granulata-Baythyonotus holopygus and the O. indicus zones changed in a 20 cm,relatively barren interval. This faunal turnover does not coincide with a lithologic change and suggests that the section would be a good location for the GSSP of the Cambrian Stage 5/Series 3.