An 850-820 Ma LIP dismembered during breakup of the Rodinia   supercontinent and destroyed by Early Paleozoic continental subduction   in the northern Tibetan Plateau, NW China

doi:10.1016/j.precamres.2016.07.007

CORC > 北京大学 > 地球与空间科学学院

	An 850-820 Ma LIP dismembered during breakup of the Rodinia supercontinent and destroyed by Early Paleozoic continental subduction in the northern Tibetan Plateau, NW China
	Xu, Xin ; Song, Shuguang ; Allen, Mark B. ; Ernst, Richard E. ; Niu, Yaoling ; Su, Li
刊名	PRECAMBRIAN RESEARCH
	2016
关键词	North Qaidam LIP Dolerite dike and basalt Eclogite Mantle plume Breakup of Rodinia Continental subduction LARGE IGNEOUS PROVINCES PB ZIRCON GEOCHRONOLOGY BIMODAL VOLCANIC-ROCKS UHP METAMORPHIC BELT U-PB SOUTH CHINA FLOOD BASALTS OCEANIC-CRUST YANGTZE BLOCK NORTHWESTERN CHINA
DOI	10.1016/j.precamres.2016.07.007
英文摘要	Neoproterozoic intraplate magmatism is widely distributed in NW China and generally thought to be related to the breakup of the Rodinia supercontinent. Here we report a fragmented Large Igneous Province (LIP) formed at 850-820 Ma in the northern margin of the Qaidam block, northern Tibetan Plateau (named herein as the "North Qaidam LIP"). The associated rocks have undergone various grades of metamorphism from greenschist to ultrahigh-pressure (UHP) eclogite facies, including the greenschist-facies Yingfeng dolerite dikes and basalts (846-821 Ma), the amphibolite- to HP granulite-facies Aolaoshan meta-volcanic sequence (protolith age of 832 Ma and metamorphic age of 439 Ma), and the North Qaidam UHP eclogites (protolith age of 847-828 Ma and metamorphic age of 440-420 Ma). Geochemical data reveal that they resemble present-day E-MORB/OIB and typical continental flood basalts. These features, together with high potential temperatures (T-p = 1434-1524 degrees C) for "primary" magmas, suggest that these basaltic rocks were most likely derived from a mantle plume source and were emplaced in a continental extensional environment. Their varying metamorphic facies record a range of locations along the underthrust continental slab from near-surface (Yingfeng dolerites/basalts), middle (Aolaoshan amphibolites) to deep (N. Qaidam UHP eclogites) sites with depths greater than 120 km. The large spatial distribution (potentially >0.1 Mkm(2)), short duration (<30 Myr) and intraplate geochemical character suggest that these igneous rocks are remnants of the North Qaidam LIP caused by the upwelling of a mantle plume during 850-820 Ma. We consider that the North Qaidam LIP represents the onset of a protracted break-up history and precedes subsequent multiple episodes of rifting. These Neoproterozoic igneous rocks in the Qaidam block were separated from the contemporaneous magmatic suites over Australia, South China and Tarim by the breakup of Rodinia, and were further destroyed by the subduction of the passive continental margin of the Qaidam block in the Early Paleozoic (440-420 Ma). (C) 2016 Elsevier B.V. All rights reserved.; Major State Basic Research Development Program [2015CB856105]; Basic geological survey program of China Geological Survey [1212011121258]; National Natural Science Foundation of China [41372060, 41572040, 41130314]; SCI(E); ARTICLE; sgsong@pku.edu.cn; 52-73; 282
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/491470]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Xu, Xin,Song, Shuguang,Allen, Mark B.,et al. An 850-820 Ma LIP dismembered during breakup of the Rodinia supercontinent and destroyed by Early Paleozoic continental subduction in the northern Tibetan Plateau, NW China[J]. PRECAMBRIAN RESEARCH,2016.
APA	Xu, Xin,Song, Shuguang,Allen, Mark B.,Ernst, Richard E.,Niu, Yaoling,&Su, Li.(2016).An 850-820 Ma LIP dismembered during breakup of the Rodinia supercontinent and destroyed by Early Paleozoic continental subduction in the northern Tibetan Plateau, NW China.PRECAMBRIAN RESEARCH.
MLA	Xu, Xin,et al."An 850-820 Ma LIP dismembered during breakup of the Rodinia supercontinent and destroyed by Early Paleozoic continental subduction in the northern Tibetan Plateau, NW China".PRECAMBRIAN RESEARCH (2016).