气候变化领域集成服务门户(CCPortal): Upper Triassic (middle Norian) conodont biostratigraphy succession from Qamdo, eastern Tibet

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DOI	10.1016/j.palaeo.2023.111915
	Upper Triassic (middle Norian) conodont biostratigraphy succession from Qamdo, eastern Tibet
	Lyu, Zhengyi; Golding, Martyn L.; Zhao, He; Yao, Huazhou; Wang, Xiangdong; Zhang, Lei; Li, Yangui; Han, Chen
发表日期	2024
ISSN	0031-0182
EISSN	1872-616X
卷号	634
英文摘要	The Late Triassic is a critical period that witnessed major biological and environmental events. The geographic range and taxonomic diversity of conodonts were significantly changed during the Late Triassic, with the geographic range contracting prior to complete extinction of the group near the end of the Triassic. In the present study, we recognize for the first time a continuous middle Norian (Upper Triassic) conodont succession from the Qamdo (Changdu) area, eastern Tibet (Xizang), which was part of the North Qiangtang and Qamdo-Simao Block (NQ-QSB) located in the northeastern Tethys Ocean during the Late Triassic. Four conodont zones are established from the middle Norian (Alaunian) of the Chaiwei section in Qamdo, and in ascending order these are: the Epigondolella spiculata Zone, the Orchardella elongata Zone, the Mockina postera Zone, and the E. serrulata Zone; the neighboring Tuoba section also records these four zones, in addition to the upper lower Norian (upper Lacian) Ancyrogondolella uniformis Zone. All of these zones (except for the M. postera Zone) have been recognized for the first time in eastern Tibet. The Lacian-Alaunian boundary is tentatively placed at the level of sample CW-3 at the Chaiwei section and at the level of sample TBL-36 at the Tuoba section by the first occurrence (FO) of E. spiculata in each section. The position of the Alaunian-Sevatian boundary (ASB) is uncertain since the conodont assemblage from the top of the Bolila Formation at the study sections lacks age-diagnostic elements. The conodonts recovered from the Qamdo area have not only dated the Bolila Formation but also refined the conodont biostratigraphic zonation of the Alaunian in the study area. This allows improved correlation between the faunas of Qamdo and their counterparts elsewhere in Tibet and Europe, although the conodont zonations from these regions display lower precision than those established from North America. The Alaunian conodont faunas at Chaiwei and Tuoba appear to be dominated by juvenile specimens; this often appears to be the case in the Alaunian of the Tethyan Realm, but seems not occur in North America. This may suggest that the conodonts living in these two realms may have inhabited different ecological environments. The faunal turnover around the Lacian-Alaunian transition, with the evolution of Epigondolella, Orchardella, and Mockina from Ancyrogondolella, can be recognized in both study sections, although it is more remarkable in the Tuoba section. Although the lack of previous detailed studies of Norian conodont biostratigraphy from Tibet hampers correlation in this region and beyond, this study demonstrates the possibility of establishing high-resolution conodont biostratigraphic successions from Tibet in the future, since the conodont faunas recognized from Tibet and adjacent areas (e.g., Baoshan) suggest that relatively complete Norian strata exist in these regions. Overall, this study also provides new data to improve our understanding of conodont evolution during the Alaunian, and is significant in providing palaeontological data for studying the palaeogeographic evolution of eastern Tethyan ocean basins in the Late Triassic.
关键词	Late Triassic Conodont biostratigraphy Changdu Basin North Qiangtang Tethys
英文关键词	INDUAN-OLENEKIAN BOUNDARY; NANPANJIANG BASIN; GSSP CANDIDATE; SECTION; RECORD; PROVINCE; CARBON; CHAOHU; AREA; STRATIGRAPHY
WOS研究方向	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS记录号	WOS:001133566300001
来源期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/282868
作者单位	China University of Geosciences - Wuhan; Natural Resources Canada; Lands & Minerals Sector - Natural Resources Canada; Geological Survey of Canada; China University of Geosciences - Wuhan; China Geological Survey; Wuhan Center, China Geological Survey; China University of Geosciences - Wuhan
推荐引用方式 GB/T 7714	Lyu, Zhengyi,Golding, Martyn L.,Zhao, He,et al. Upper Triassic (middle Norian) conodont biostratigraphy succession from Qamdo, eastern Tibet[J],2024,634.
APA	Lyu, Zhengyi.,Golding, Martyn L..,Zhao, He.,Yao, Huazhou.,Wang, Xiangdong.,...&Han, Chen.(2024).Upper Triassic (middle Norian) conodont biostratigraphy succession from Qamdo, eastern Tibet.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,634.
MLA	Lyu, Zhengyi,et al."Upper Triassic (middle Norian) conodont biostratigraphy succession from Qamdo, eastern Tibet".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 634(2024).