Emplectopteridium在禹县剖面中两次出现的时代意义

作者在河南省禹县方山滴水潭石炭—二叠系剖面中,发现 Emplectopteridium 在不同层位两次出现。因此,根据古生物组合、岩性和岩相特征及区域对比,认为石炭系与二叠系的分界线,应放在该植物化石第一次出现层位的底部,即夏国英所建立的 Sehwagerina nobilis 带的底部。这一界线大体相当于湘东南及华北地区 Pseudoschwagerina 带的下部。这个划分意见,将以往由于单独以动物或植物化石作为划分依据而出现的矛盾问题,得到了较为合理的解决。

THE AGE SIGNIFICANCE OF TWO OCCURRENCES OF EMPLECTOPTERIDIUM IN THE SECTION OF YUXIAN COUNTY

Emplectopteridium is found to appear twice in different stratigraphical Lorizons in the Permian-Carboniferous section of Dishuition,Fanshan,Yuxian, Henan.Therefore,according to the fossil assemblage,lithologlogical and litho- facies characteristics and regional correlation,it is considered that the Carboni- ferous-Permian boundary should be placed at the base of the horizon where plant fossils first appear,i.e.the base of the Schwagerina nobilis Zone establi- shed by Xia Guoying.This boundary largely corresponds to the lower part of the Pseutoschwagerina Zone in southeastern Hunan and North.China.Thus the contradiction that arose as animal or plant fossils alone were used as the crite- rion for the definition of the boundary has been solved relatively reasonably.