The Late Palaeozoic Conodont Biostratigraphy Of The De'E Distriction,Longlin,Guang Xi

Guangxi is one of the best areas for late Paleozoic stratigraphic development in china.A continuous carbonate strata sequence of late Paleozoic is exposed in De'e,Longlin,Guangxi,which provides a good basis for the study of the conodont biostratigraphy sequence of Late Paleozoic.This thesis focuses the study on the Paleozoic conodont biostratigraphy of the De'e section,in which the lithostratigraphic units in ascending include D3 r,C1-2d,C2 h,C2P1m,Pbls1,Pbls2 and Pbls3.96 samples were collected for conodont biostratigraphy from De'e section.In this study,abundant and well preserved conodonts were gained from the samples pf the De'e section and 43 genera and 52 species are identified.Nine conodont zones are recognized in ascending order as follows:(1)Palmatolepis marginifera zone(D3);(2)Palmatolenpis rugose trachytera-Palmatolepis glabra glabra assemblage zone(D3);(3)Siphonodella sulcate zone(C1);(4)Siphonodella crenulata zone(C1);(5)Siphonodella isosticha zone(C1);(6)Jinogondolella altudaensis zone(P2);(7)Clarkina subcarinata-Clarkina changxingensis assemblage zone(P3);(8)Clarkina yini zone(P3);(9)Clarkina meishanensis zone(P3).D/C boundary is usually identified by the first appearance of the Siphonodella sulcate.In this thesis,the first appearance Siphonodella sulcate was found in the sample 2m above the bottom of the Bed 28 in the section.Therefore,the D/C boundary should close to the bottom the Bed 28,which is marked by the bottom of the Siphonodella sulcate Zone.