广西东攀剖面二叠-三叠系界线附近头足类动物群与地质时代讨论

在广西东攀二叠-三叠系界线剖面中发现了Domataceras guangxiensis, Lopingoceras guangdeensis Zhao,Liang et Zheng,Schizoloboceras fusuiensis, Agathiceras sp., Stacheoceras sp.,Pernodoceras robustum Chao et Liang,Dushanoceras cf.rotolarium Zhao, Liang et Zheng,Huananoceras cf.perornatum Chao et Liang,Qianjiangoceras sp.,Laibinoceras cf.compressum Yang,Glyptophiceras sp.,Lytophiceras cf. chamunda(Diener),Ophiceras tingi Tien,Ophiceras sp.化石.在剖面的第2～12-2层产Pernodoceras,Dushanoceras,Huananoceras和Qianjiangoceras化石,均为长兴期菊石带Pseudotirolites-Rotodiscoceras的共生化石.第12-3层产长兴期菊石Laibinoceras cf.compressum Yang.第13-1A～16层产Lytophiceras和 Ophiceras,为早三叠世菊石带Ophiceras-Lytophiceras的带化石.东攀剖面菊石的分布及其与华南其他地区的对比研究表明,广西东攀剖面二叠-三叠系界线位于第12-3层(厚55 cm)内部或者位于第13-1A层的底部.

Permian-Triassic Cephalopods from Dongpan Section,Guangxi,and Its Geological Significance

In the Permian-Triassic intervals of Dongpan section, Guangxi,South China,an cephalopods is discovered including Lopingoceras guangdeensis Zhao, Liang et Zheng,Agathiceras sp.,Stacheoceras sp.,Pernodoceras robustum Chao et Liang,Dushanoceras cf.rotolarium Zhao, Liang et Zheng,Huananoceras cf.perornatum Chao et Liang,Qianjiangoceras sp.,Laibinoceras cf.compressum Yang,Lytophiceras cf.chamunda (Diener), Ophiceras tingi Tien,and Ophiceras sp..Among this fauna,ammonoids Pernodoceras,Dushanoceras,Huananoceras and Qianjiangoceras are discovered from bed 2 to bed 12-2, and regarded as the coexisting elements of the Changhsingian ammonoid Pseudotirolites-Rotodiscoceras zone, indicating Late Permian in age.While found ammonoid Laibinoceras cf.compressum is discovered from bed 12-3, whose type species was found in the Changhsingian strata in Laibing, Guangxi. Ammonoids Lytophiceras and Ophiceras are discovered in bed 13-1A to bed 16, and regarded as the zonal fossils of the early Triasic ammonoid Ophiceras-Lytophiceras zone, indicating the Early Triassic in age. The Permian-Triassic boundary in Dongpan section is located in bed 12-3 or between bed 12-3 and bed 13-1A based on the date of ammonoid fauna and its correlation with the ammonoid faunas from other sections in South China.