Integrated analyses constraining the provenance of sandstones, mudstones, and conglomerates, a case study the Laojunshan conglomerate, Qilian orogen, northwest China

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	Integrated analyses constraining the provenance of sandstones, mudstones, and conglomerates, a case study the Laojunshan conglomerate, Qilian orogen, northwest China
	Yan, Z (Yan, Zhen); Xiao, WJ (Xiao, Wenjiao); Wang, ZQ (Wang, Zongqi); Li, JL (Li, Jilian)
刊名	CANADIAN JOURNAL OF EARTH SCIENCES
	2007
卷号	44 期号:7 页码:961-986
ISSN号	0008-4077
英文摘要	The Qilian orogenic belt in the northern Tibetan plateau connects the Altaids to the north with the Tethyan orogenic system to the south and occupies a key tectonic position in the evolution and assembly of Asia. The belt contains a wide range of subduction-accretion-related petrotectonic units. The Early-Middle Devonian Laojunshan conglomerate, deposited unconformably upon Cambrian-Silurian strata along the northern margin of the North Qilian terrane, contains a record of the late Paleozoic tectonism of the Qilian orogen. Its provenance and tectonic setting are critical in understanding not only the tectonic evolution of Tibetan plateau, but Paleozoic global reconstructions as well. The composition of elastic conglomerates and heavy mineral assemblages of sandstones suggests that coeval mafic, felsic, metamorphic, and sedimentary rocks were the main sources. The geochemistry of volcanic clasts and paleocurrent and paleogeographic data suggest derivation from subduction-accretion complexes in the North Qilian terrane. The geochemistry of siltstones and mudstones indicates that the Laojunshan conglomerate was derived from an arc and accumulated in an active continental margin. Geochemical data of granitoid clasts suggest that they were derived from Ordovician-Silurian subduction-related magmatic rocks. Mafic and ultramafic clasts, chromite, and magnetite decrease upwards in the stratigraphy whereas metamorphic, sedimentary and granitoid clasts, and garnet increase. These data imply that mafic rocks were the predominant source during initial deposition. Regional studies suggest that the North China plate subducted southwards and produced subduction-related arc magmatism along the southern margin of the North Qilian terrane during the Early-Middle Devonian. Therefore, we interpret the Laojunshan conglomerate as a fore-arc basin fill.
学科主题	沉积学与沉积岩
WOS关键词	TRACE-ELEMENT CHARACTERISTICS ; PENNSYLVANIAN-PERMIAN AGE ; SEDIMENTARY-ROCKS ; NW CHINA ; GEOCHEMISTRY ; GEOCHRONOLOGY ; EVOLUTION ; BASINS ; SHALES ; DISCRIMINATION
WOS研究方向	Geology
语种	英语
出版者	CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS
WOS记录号	WOS:000249709000006
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/38473]
专题	中国地质调查局
作者单位	Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Yan, Z ,Xiao, WJ ,Wang, ZQ ,et al. Integrated analyses constraining the provenance of sandstones, mudstones, and conglomerates, a case study the Laojunshan conglomerate, Qilian orogen, northwest China[J]. CANADIAN JOURNAL OF EARTH SCIENCES,2007,44(7):961-986.
APA	Yan, Z ,Xiao, WJ ,Wang, ZQ ,&Li, JL .(2007).Integrated analyses constraining the provenance of sandstones, mudstones, and conglomerates, a case study the Laojunshan conglomerate, Qilian orogen, northwest China.CANADIAN JOURNAL OF EARTH SCIENCES,44(7),961-986.
MLA	Yan, Z ,et al."Integrated analyses constraining the provenance of sandstones, mudstones, and conglomerates, a case study the Laojunshan conglomerate, Qilian orogen, northwest China".CANADIAN JOURNAL OF EARTH SCIENCES 44.7(2007):961-986.