LATEST BIOSTRATIGRAPHIC ADVANCES OF CAMBRIAN-ORDOVICIAN BOUNDARY IN QINGZHOU AREA, SHANDONG

A new study on conodont biostratigraphy of Cambrian-Ordovician boundary in Yaowangshan Section, Qingzhou area, Shandong Province is first reported in this paper. 9 conodont zones have been recognized in the Chaomidian limestone formation, among which 3 are from the Lower Ordovician and 6 from the Fengshanian Stage of upper Upper Cambrian. The first discovery of the Cambrian-Ordovician Boundary species Iapetognathus fluctivagus in this section is of great significance. It will provide a new rule for Cambrian-Ordovician Boundary study in the Shandong area as well as in the whole North China. Additionally, through the further detailed study, the well-developed Yaowangshan Section will probably become the stratotype section in China, which will deeply affect the establishment of Cambrian stages, a still uncompleted work so far.