THE UPPER ORDOVICIAN OF THE WESTERN BORDER OF NORTH CHINA PLATFORM
华北地台西缘的上奥陶统

The Upper Ordovician of the western border of North China Platform may be subdivided into two formations. Taoqupo Formation (upper part of the Caradoc Stage) and Beiguoshan Formation (lower part of the Ashgill Stage).In the upper part of Upper Ordovician, one of the most characteristic features of the Coral faunas is the considerable development and distribution of Agetolitids (Agetolites, Agetolitella, Subagetolites) and Proporids (Plasmo-porella), mixed with the Baltic Sarcinula and the North American-Siberian Calapoecia, Rhabdotetradium and the abundant genus Favistella.During Upper Ordovician the transgression in North China platform was from the Southwest to the Northeast.