The Ar-40/Ar-39 and Rb-Sr chronology of the Precambrian Aksu blueschists   in western China

doi:10.1016/j.jseaes.2012.05.024

CORC > 北京大学 > 地球与空间科学学院

	The Ar-40/Ar-39 and Rb-Sr chronology of the Precambrian Aksu blueschists in western China
	Yong, Wenjun ; Zhang, L. ; Hall, C. M. ; Mukasa, S. B. ; Essene, E. J.
刊名	journal of asian earth sciences
	2013
关键词	Precambrian blueschist Aksu blueschist Ar-40/Ar-39 Rb-Sr Isotopes PRESSURE METAMORPHIC ROCKS PB ZIRCON GEOCHRONOLOGY DORA MAIRA MASSIF BASIN NW CHINA TARIM BASIN EXCESS ARGON PALEOGEOGRAPHIC EVOLUTION ISOTOPIC HETEROGENEITIES TECTONIC IMPLICATIONS NORTHWEST CHINA
DOI	10.1016/j.jseaes.2012.05.024
英文摘要	Three metapelite samples from the Aksu blueschist terrane, Xinjiang, China, were dated by the Ar-40/Ar-39 method on separated phengite grains, obtaining plateau ages in the range of 741-757 Ma. In contrast, the measured Rb and Sr isotope data for the three samples yielded isochron ages ranging from 630 Ma to 900 Ma, suggesting large heterogeneity in the blueschist protolith and suppression of diffusional exchange owing to the low-temperature metamorphic conditions. Because the protolith of Aksu blueschist is composed of oceanic materials that formed Ar-40-free phengite during HP and UHP metamorphism and the apparent Ar-40/Ar-39 plateaus ages in this study are similar to previous K-Ar and Rb-Sr ages, the existence of excess argon in these rocks is considered to be insignificant. As a result, the Ar-40/Ar-39 plateau ages in this study (ca. 750 Ma) likely represent the approximate time for peak metamorphism, given the low peak metamorphic temperatures for the Aksu blueschist terrane (300-400 degrees C). This strongly implies that modern style, cold subduction tectonics operated along the margin of the Aksu terrane no later than 750 Ma, in Neoproterozoic time. (C) 2012 Elsevier Ltd. All rights reserved.; Geosciences, Multidisciplinary; SCI(E); 10; ARTICLE; ,SI; 197-205; 63
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/225963]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Yong, Wenjun,Zhang, L.,Hall, C. M.,et al. The Ar-40/Ar-39 and Rb-Sr chronology of the Precambrian Aksu blueschists in western China[J]. journal of asian earth sciences,2013.
APA	Yong, Wenjun,Zhang, L.,Hall, C. M.,Mukasa, S. B.,&Essene, E. J..(2013).The Ar-40/Ar-39 and Rb-Sr chronology of the Precambrian Aksu blueschists in western China.journal of asian earth sciences.
MLA	Yong, Wenjun,et al."The Ar-40/Ar-39 and Rb-Sr chronology of the Precambrian Aksu blueschists in western China".journal of asian earth sciences (2013).