Conodont Biostratigraphy across the Permian-Triassic Boundary at the Xinmin Section, Guizhou, South China

• Published in: Journal of earth science (Wuhan, China) Vol. 25; no. 5; pp. 779 - 786
• Main Authors: Zhang, Ning, Jiang, Haishui, Zhong, Wenli, Huang, Haohao, Xia, Wenchen
• Format: Journal Article
• Language: English
• Published: Heidelberg China University of Geosciences 01.10.2014; Springer Nature B.V; Faculty of Earth Sciences, China University of Geosciences, Wuhan430074, China%State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan430074, China
• Subjects: Biogeosciences; Chert; Cherts; China; Earth and Environmental Science; Earth science; Earth Sciences; Formations; Geochemistry; Geology; Geotechnical Engineering & Applied Earth Sciences; Mudstone; Permian; Permian-Triassic boundary; Rocks; Sedimentation; Sedimentation & deposition; Siliceous rocks; Stratigraphy; Triassic; Zonation; 三叠系; 中国; 二叠系; 层状硅质岩; 牙形石带; 生物地层框架; 界线; 贵州; Early Triassic chert; Permian-Triassic; conodont; Xinmin Section
• ISSN: 1674-487X; 1867-111X
• DOI: 10.1007/s12583-014-0472-0

A continuous sedimentation at the Xinmin Section, Anshun, Guihzou Province, with the Upper Permian Talung Formation dominated by bedded siliceous rocks, and the Lower Triassic Luolou Formation consisting mudstones and marls as well as siliceous mudstones at its basal part indicates that it represents a deeper-water basinal facies across the Permian-Triassic boundary. Based on a systematic conodont biostratigraphic work, nine conodont species belong to two genera have been identified in this study. It enable us to establish five conodont zones at this section, in ascending order, they are： Clarkina changxingensis Zone（beds 1-3-4-2）, Clarkina yini Zone（beds 4-3-5-1-1）, Clarkina meishanensis Zone（beds 5-1-2-5-2）, Hindeodus changxingensis Zone（beds 5-3-1-5-3-2） and Hindeodus parvus Zone（beds 5-3-3-5-3-4）, respectively. According to the first occurrence of Hindeodus parvus in bed 5-3-3, the Permian-Triassic boundary is placed at the base of bed 5-3-3. This conodont zonation of the Xinmin Section provides precise biostratigraphic framework for further investigations on the geological events across the Permian-Triassic boundary at this section. In addition, the new conodont data also reveals that several siliceous beds occurred at the basal Triassic. It provides an exception of Early Triassic Chert Gap.