北祁连山发现晚志留世牙形刺

THE DISCOVERY OF LATE SILURIAN CONODONTS IN THE NORTHERN QILIAN MOUNTAINS

摘要: 1980年我队进行地层断代总结时对原测“北石门子—泉脑沟山—旱峡”剖面重新进行了观察和研究。在原划为志留纪中统的泉脑沟山群之灰岩中系统采集了牙形刺样品,在其底部采得腕足类化石,部分层位中采集到了珊瑚化石。牙形刺样品经南京古生物研究所分离后,有两个样品含牙形刺,一个样品含鱼牙化石。宜昌地质矿产研究所倪世钊和新疆石油局赵治信分别对这两个样品所含牙形刺进行了鉴定,他们都认为原剖面31层所含的牙形刺为晚志留世的分子;笔者又根据《祁连山地质志》四卷三分册所列泉脑沟山剖面,对所采珊瑚化石进行了分析对比,认为泉腺沟山群的上部（q₃段）时代应属晚志留世。

Abstract: In the western sector of the Northern Qilian Mountains,late Silurian conodonts,namely,Ozarkodina cf.remscheidensis eosteinhornensis （Walliser）and Synprioniodina cf.silurica Walliser,have been found in Member“q₃”of the upper part of the middle Silurian Quannaogoushan Group which was formerly determined by the Qilianshan Geological Team of the Chinese Academy of Sciences.In this paper,according to the age of the conodonts and the lithological changes,Member “q₃”of the Quannaogoushou Group is assigned to the upper Silurian.