Discovery of Early-Middle Permian cathaysian flora in Manduhubaolage area, Dong Ujimqin Qi, Inner Mongolia, China and its geological significance

Manduhubaolage of Dong Ujimqin Qi，Inner Mongolia，is located in the north of Hegenshan about 240km toward to 42°. We found early-middle Permian stratum which contains cathaysian flora first time. We have identified 7 genus 11 species in the cathaysian flora. They can compare with the floras which were well studied in North China plate, and their times could be identified as early-middle Permian. This discovery enlightened us to consider the questions that are the suture place and the collision time of Siberia and North China plate. The collision time of the two plates should be earlier than early Permian.