一条新发现的深水相泥盆系—石炭系界线剖面:中国贵州紫云火花剖面

摘要

在贵州省紫云县火花乡新发现一条泥盆系—石炭系界线剖面.火花剖面位于新修的乡村公路边上,出露有连续的上泥盆统代化组、长顺页岩和下石炭统王佑组.为了研究泥盆系—石炭系界线,对该剖面进行了实测,并采集、分析了30多个牙形刺样品.根据分析结果,在代化组和长顺页岩中识别出一些牙形刺,如Palmatolepis tenuipunctata,Pa.glabra,Pa.marginifera,Pa.gracilis,Polygnathus vogesi和Polygnathus purus purus.王佑组中的牙形刺较少,如Polygnathus communis和Hindeodella subtilis等,目前尚不具有建立生物地层单位的条件.根据与长顺睦化剖面和德国Hasselbachtal剖面岩性、沉积特征和牙形刺生物地层的对比,暂将火花剖面的泥盆系—石炭系界线放置于25层与26层之间,即长顺页岩与王佑组之间.%This paper introduces a new section of the Devonian-Carboniferous boundary in Huohua area,Ziyun County,Guizhou Province,South China.The Huohua section of Upper Devonian and Lower Carboniferous is well-outcropped along a new countryside road.In this section,the D-C boundary beds can be grouped into three litho-units:the Daihua Formation,the Changshun Shale and the "Wangyou Formation",fiom which more than 30 conodont samples were collected and processed.According to our current study,some important conodonts in the Daihua Formation and the Changshun Shale have been recognized,such as Palmatolepis tenuipunctata,Pa.glabra,Pa.marginifera,Pa.gracilis,Polygnathus vogesi and Polygnathus purus purus.A few conodonts have been found from the Wangyou Formation,such as Polygnathus communis and Hindeodella subtilis.Based on the comparison with the Muhua section in Changshun county and the Hasselbachtal section in Germany in lithology,sedimentology and conodont biostratigraphy,the D-C boundary could be temporarily placed between Bed 25 and Bed 26,namely between the Changshun Shale and the Wangyou Formation.