First Records of Late Triassic Conodont Fauna and δ13Ccarb from the Dengdengqiao Section, Dangchang County, Gansu Province, Northwestern China

• Published in: Journal of earth science (Wuhan, China) Vol. 32; no. 3; pp. 646 - 656
• Main Authors: Li, Hanxiao, Wang, Miaoyan, Zhang, Muhui, Wignall, Paul B., Rigo, Manuel, Chen, Yanlong, Wu, Xianlang, Ouyang, Zhumin, Wu, Baojin, Yi, Zhaoyang, Zhang, Zaitian, Lai, Xulong
• Format: Journal Article
• Language: English
• Published: Wuhan China University of Geosciences 2021; Springer Nature B.V; School of Earth Sciences, China University of Geosciences, Wuhan 430074, China%School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China%School of Earth Sciences, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China%School of Earth and Environment, University of Leeds, Leeds LS29JT, UK%Department of Geosciences, University of Padova, Via Gradenigo 6, 35131, Padova, Italy%Shaanxi Key Laboratory of Early Life and Environments, State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, Xi'an 710069, China%Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China%Wuhan Center of Geological Survey, Wuhan 430205, China
• Subjects: Algae; Biogeosciences; Carbon isotopes; Carbonates; Earth and Environmental Science; Earth Sciences; Fauna; Geochemistry; Geology; Geotechnical Engineering & Applied Earth Sciences; Identification; Marine ecosystems; Marine organisms; New records; New species; Records; Stratigraphy; Triassic; China; Late Triassic; Qinling; conodonts; Julian
• DOI: 10.1007/s12583-021-1428-9
• ISSN: 1674-487X

Based on a study of 49 conodont and 57 geochemical samples from the Upper Triassic, carbonate-dominated Dengdengqiao Formation, Qinling Basin, China, the Carnian conodonts and carbon isotope records are first reported. Two genera and four species have been identified amongst 87 conodont elements: Mosherella praebudaensis , Mo. longnanensis sp. nov., Mo. sp., and “ Misikella” longidentata . The presence of Mo. praebudaensis indicates that the lower part (bed 2) of the formation is attributable to the Julian (lower Carnian) substage. A radiolarian fauna identified in a previous study belongs to the upper Carnian, but the sampling horizon is unclear. The δ 13 C carb curve shows a ∼1.8‰ negative excursion beginning from upper part of bed 3, but its stratigraphic location is uncertain. The Dengdengqiao Formation is clearly at least partly of Carnian age but could include younger strata. The abundant calcareous algae at the section is probably due to some transport rather than preserved in site. The unusual ecosystem with rare marine organisms may reflect long-term stressful and unfavorable conditions at Dengdengqiao.