Detrital zircon U-Pb ages of Middle Ordovician flysch sandstones in the western ordos margin New constraints on their provenances, and tectonic implications

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	Detrital zircon U-Pb ages of Middle Ordovician flysch sandstones in the western ordos margin New constraints on their provenances, and tectonic implications
	Zhang, J (Zhang Jin); Li, JY (Li Jinyi); Liu, JF (Liu Jianfeng); Feng, QW (Feng Qianwen)
刊名	JOURNAL OF ASIAN EARTH SCIENCES
	2011
卷号	42 期号:5 特刊 SI 页码:1030-1047
关键词	Middle ordovician Alax massif U-Pb dating Detrital zircon Foreland basin
ISSN号	1367-9120
英文摘要	The southwestern Ordos Margin is located between the Alax massif to the northwest, the North China Craton (NCC) to the east, and the North Qilian Orogenic Belt (NQOB, part of the Chinese Central Orogenic belt) to the southeast. Controversy surrounds the tectonic setting of the Western Ordos Margin in the Early Paleozoic; key questions are whether the Alax massif connected to the NCC in the Early Paleozoic, when exactly this event did happen, where the Lower Paleozoic sedimentary rocks along the southwestern Ordos had their provenances, and whether the so-called Helan aulacogen formed in the Ordovician. Laser-ablation inductively coupled plasma mass spectroscopy U-Pb dating of detrital zircons in four samples from Middle Ordovician sandstones in the Xiaoluo Shan and Niushou Shan located in the Western Ordos yield a majority of (206)Pb/(238)U ages between 800 and 1000 Ma, a smaller group yields (206)Pb/(238)U ages between 500 and 600 Ma; there are a few zircons with other ages, including some older than 2400 Ma. The youngest (206)Pb/(238)U ages of the four samples are similar and range from 533 +/- 3 Ma to 556 +/- 4 Ma. These zircon U-Pb ages combined with several lines of sedimentary evidence imply that the so-called Helan aulacogen did not exist in the Ordovician; a peripheral foreland basin related to the NQOB developed instead. The detritals mainly came from the Alax massif, the North Qilian Arc, and the Dunhuang massif; and the NCC can be excluded as an important provenance. This study also suggested that the Alax massif did not connect with the NCC before the Middle Ordovician, and that the Alax is similar to the Yangtze Craton or the Tarim Craton with a majority of intrusions in the range of 800-1000 Ma and containing Precambrian tillites, which are characteristics that differ from the NCC. (C) 2011 Elsevier Ltd. All rights reserved.
学科主题	构造地质学
WOS关键词	NORTH CHINA CRATON ; GEOCHRONOLOGICAL EVIDENCE ; SEDIMENTARY BASINS ; TIBETAN PLATEAU ; EVOLUTION ; GNEISSES ; TERRANE ; HISTORY
WOS研究方向	Geology
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000296304700018
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39383]
专题	中国地质调查局
作者单位	Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China
推荐引用方式 GB/T 7714	Zhang, J ,Li, JY ,Liu, JF ,et al. Detrital zircon U-Pb ages of Middle Ordovician flysch sandstones in the western ordos margin New constraints on their provenances, and tectonic implications[J]. JOURNAL OF ASIAN EARTH SCIENCES,2011,42(5 特刊 SI):1030-1047.
APA	Zhang, J ,Li, JY ,Liu, JF ,&Feng, QW .(2011).Detrital zircon U-Pb ages of Middle Ordovician flysch sandstones in the western ordos margin New constraints on their provenances, and tectonic implications.JOURNAL OF ASIAN EARTH SCIENCES,42(5 特刊 SI),1030-1047.
MLA	Zhang, J ,et al."Detrital zircon U-Pb ages of Middle Ordovician flysch sandstones in the western ordos margin New constraints on their provenances, and tectonic implications".JOURNAL OF ASIAN EARTH SCIENCES 42.5 特刊 SI(2011):1030-1047.