New data on the Wuliu-Zengjiayan section (Balang, South China), GSSP candidate for the base of Cambrian Series 3

Abstract

The Wuliu-Zengjiayan section at Balang, Guizhou Province, China, records an unbroken succession of marine shales, mudrocks and limestones through the interval under consideration as including base of Cambrian Series 3. The means for recognising the base of this Series (which will replace the Traditional Middle Cambrian) is undecided at present, but will involve a primary correlation tool in addition to secondary stratigraphic correlation criteria. Guide fossils under consideration as tools for constraining the position of the base of Series 3 include Oryctocephalus indicus and Ovatoryctocara granulata, both of which occur in the lower part of the Kaili Formation. Preliminary information also shows that the ROECE carbon isotopic excursion is recognisable in this formation. This indicates that the Wuliu-Zengjiayan section is an excellent GSSP candidate for the base of Cambrian Series.