Conodont Biostratigraphy Of Devonian In Lanxu,Daxin,Guangxi

Geological survey in Guangxi began in 1920's,and a lot of important research achievements have been obtained in stratigraphy,tectonics,mineral exploration,hydrology,remote sensing and so on.The study on biostratigraphy is one of the important contents of the geological survey.The Devonian sedimentary sequence is well developed in Guangxi,which contains abundant microfossils such as foraminifera,ostracods,and conodont.Therefore,it is an ideal area to study the Devonian biostratigraphy.The study area of this thesis is located in the Xidamingshan area,Guangxi.which belong to the central Xidamingshan uplift of Youjiang fold system in South China active belt of Southern China plate where outcrops a good Devonian sequence rich in conodonts.In this thesis,the study of the conodont biostratigraphy in the Devonian section of Lanxu,Daxin,Guangxi.The conodont fossils were identified to 86 species of 27 genera.which were classified into four zones: Palmatolepis marginifera zone,Palmatolepis rhomboidea zone,Palmatolepis crepida zone and Palmatolepis punctata zone.It is concluded that the age of the Wuzhishan Formation of Lanxu,Daxin,Guangxi should belong to early Frasnina to middle Famennian and Frasnian-Famennian boundary(F-F boundary)should be located in the samples between D0342 and D036HB1,which from the bottom of the Wuzhishan Formation.