滇西保山西邑地区香山组一段牙形石的发现及其时代意义

The discovery of conodonts from the first Member of the Xiangshan Formation in the Xiyi area, Baoshan, western Yunnan Province, and its biostratigraphic significance

摘要: 保山西邑铅锌矿区香山组一段灰岩牙形石丰富，包括5属7种1个相似种及2个未定种，分别为：Ancyrodella curvata，A.nodosa，A.spp.，Ancyrognathus triangularis，Icriodus alternatus alternatus，I.sp.，Palmatolepis hassi，Pa.simpla，Polygnathus webbi，Po.cf.tenellus和Po.sp.。该牙形石组合面貌可与上泥盆统Late Palmatolepis rhenana带对比，表明研究区内香山组一段的时代为晚泥盆世弗拉斯期晚期，并非早石炭世。

Abstract: The first Member of Xiangshan Formation in the Xiyi Pb-Zn mining area of Baoshan is rich in conodont, and 5 genera, 7 species, 1 conformis species and 2 undetermined species were identified.They are:Ancyrodella curvata, A.nodosa, A.spp., Ancyrognathus triangularis, Icriodus alternatus alternatus, I.sp., Palmatolepis hassi, Pa.simpla, Polygnathus webbi, Po.cf.tenellus, and Po.sp..The conodonts assemblage is considered to be correlated with Late Palmatolepis rhenana zone, suggesting that the first Member of Xiangshan Formation is Late Frasnian of Late Devonian instead of Early Carboniferous in age.