Original age call: Caradocian-Ashgillian
Webby pers comm.
At Beiguoshan the patch reefs are similar [see reef 2511], but are especially dominated by corals and stromatoporoids, and over 20 m thick and 100 m wide (Zhou and Ye 1996). Zhou et al. (1989)  listed representatives of the illaenid-cheirurid trilobite biofacies in the Beiguoshan Formation at Longxian and Taoqupo Formation at Yaoxian (northeast of Dongzhuang). 