关键词: 牙形石, 关岭组, 羊圈?楚皮凹剖面, 盘县, 贵州省

Abstract: The conodonts biostratigraphy from the Upper Member of the Guanling Formation to the basal Yangliujing Formation in Yangjuan-Chupiwa Section was re-analysed and the conodont Neogondolella constricta cornuta, Neogondolella constricta longa, Neogondolella constricta balkanica, Neogondolella alpina alpina, Neogondolella cf. Neogondolella acuta, Paragondolella excelsa, Paragondolella torna?sis were described. Based on the stratigraphical distribution and morphological variations of these conodonts, five conodont zones were re-established and the relevant biostratigraphic comparisons were made. The results reveal that: 1) From the Upper Member of the Guanling Formation to the basal Yangliujing Formation, five conodont zones can be investigated. In ascending stratigraphical order, they are Nicoraella germanica Zone (the bottom undefined), Nicoraella kockeli Zone, Neogondolella bifurcata Zone, Neogondolella constricta Zone, and Neogondolella constricta cornuta Zone (the top undefined); 2) These conodont zones are comparable to the same-named conodont zones of the Upper Longtou Formation at Qingyan Section (platform-margin slope) and of the Guandao wedge at Guandao (2) Section (basin-margin facies) in Guizhou Province, and these conodonts are also present in the ammonoid binodosus Zone, trinodosus Zone, and reitizi Zone in the West Tethys; 3) It further proves that the studied strata can be considered as the Pelsonian-Illyrian substages of the Anisian stage (Middle Triassic), not going into the Ladinian of the Middle Triassic.

Key words: conodont, Guanling Formation, Yangjuan-Chupiwa Section, Panxian County, Guizhou Province