BIOSTRATIGRAPHY OF THE HUANGNITANG RESERVOIR SECTION IN CHANGSHAN,ZHEJIANG PROVINCE

In order to protect effectively the Huangnitang GSSP section of the Darriwilian Stage(Ordovician) ,a new section(the Reservoir section) near the GSSP section was excavated,to meet the demands of further research and public fossil collecting. The Reservoir section is well-exposed and has a stratigraphic sequence well comparable to that of the GSSP section,including in ascending order the Yinchufu,Ningkuo and Hulo Formations. The section contains abundant exquisitely preserved fossils,including pyritized graptolites,brachiopods,trilobites,phyllocarids and aecal pellets. Five graptolite biozones,in ascending order the Corymbograptus deflexus,Azygograptus suecicus,Exigraptus clavus,Undulograptus austrodentatus and Acrograptus ellesae Biozones are recognized in the section,showing a biostratigraphic sequence identical to that of the Huangnitang GSSP section. The reservoir section,with its complete sequence,abundant fossils and well exposure,may serve as a qualified supplementary section for the studies of the Darriwilian Stage.