气候变化领域集成服务门户(CCPortal): New radiometric dating constrains the time for initiation of the Karakorum fault zone (KFZ), SW Tibet

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DOI	10.1016/j.tecto.2009.06.016
	New radiometric dating constrains the time for initiation of the Karakorum fault zone (KFZ), SW Tibet
	Wang, Shifeng; Fang, Xiaomin; Lai, Qingzhou; Zheng, Dewen; Wang, Yanbin
通讯作者	Wang, SF (通讯作者)
发表日期	2009
ISSN	0040-1951
EISSN	1879-3266
起始页码	503
结束页码	513
卷号	475 期号:3-4
英文摘要	The Karakorum fault zone (KFZ), composed of strike-slip faults, has played an important role in intra-continental deformation during the Cenozoic convergence between the Indian and Eurasian plates. However, the spatial and temporal evolution of the KFZ remains under debate. This paper reports new zircon U-Pb Sensitive High Resolution Ion MicroProbe (SHRIMP) and biotite Ar-40/Ar-39 ages for samples from the fault zone to clarify the timing of events. The ages of Zircon U-Pb fall mainly around 47-50 Ma, which corresponds to a period of important magmatic activity of the Gangdese granitic belt (also known as the Trans-Himalayan magmatic belt). A metamorphic event followed in the period around 32 Ma, and that was then followed by a medium temperature cooling event between about 12 and 7.7 Ma. Biotite Ar-40/Ar-39 ages provide evidence that the 12-7.7 Ma cooling event coincides with the initiation of the KFZ cutting through the Ayilari granite. The Ayilari granite pluton does not seem to have experienced the separate 25-23 Ma cooling event, as shown in previous studies 60-80 km west of the current study area [Lacassin, R., Valli, F., Arnaud, N., Leloup, PH., Paquette, J.L, Li, H, Tapponnier, R, Chevalier, M.L. Guillot. S.. Maheo, G., Xu, Z., 2004. Large-scale geometry, offset and kinematic evolution of the Karakorum fault Tibet. Earth and Planetary Science Letters 219 (3-4), 255-269.; Valli, F., Arnaud, N., Leloup, H.P., Sobel, E.R., Maheo, G., Lacassin, R., Guillot, S., Li, H., Tapponnier, P., Xu, Z., 2007. Twenty million years of continuous deformation along the Karakorum fault western Tibet: a thermochronological analysis. Tectonics 26, doi: 10.1029/2005TC001913.: Valli, F., Leloup, P., Paquette, J., Arnaud, N., L!, H., Tapponnier, P., Lacassin, R., Guillot, S., Liu, D., Deloule, E., Xu, Z., Mahe'o, G., 2008. New U-Th/Pb constraints on timing of shearing and long-term slip-rate on the Karakorum fault. Tectonics 27, doi:10.1029/200TrC002184.]. We conclude that the 25-23 Ma cooling event bears no relationship to the activity of the KFZ, but resulted from a local metamorphic event caused either by a regional tectonic event (such as activity of the south Kailas thrust fault) or by magmatism around Shiquanhe (also known as Gar). The study of the KFZ around Namru supports the opinion that the KFZ propagated along the fault strike to the Gar-Menshi area around 12 Ma. (C) 2009 Elsevier B.V. All rights reserved.
关键词	LARGE-SCALE GEOMETRY U-PB GEOCHRONOLOGY SOUTHWEST TIBET WESTERN TIBET STRUCTURAL EVOLUTION KINEMATIC EVOLUTION DEFORMATION TECTONICS SOUTHERN ASIA
英文关键词	Karakorum fault zone (KFZ); Ayilari granite; Trans-Himalayan magmatic belt (THB); U-Pb SHRIMP age; Ar-40/Ar-39 age
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000273524100008
来源期刊	TECTONOPHYSICS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/257675
推荐引用方式 GB/T 7714	Wang, Shifeng,Fang, Xiaomin,Lai, Qingzhou,et al. New radiometric dating constrains the time for initiation of the Karakorum fault zone (KFZ), SW Tibet[J]. 中国科学院青藏高原研究所,2009,475(3-4).
APA	Wang, Shifeng,Fang, Xiaomin,Lai, Qingzhou,Zheng, Dewen,&Wang, Yanbin.(2009).New radiometric dating constrains the time for initiation of the Karakorum fault zone (KFZ), SW Tibet.TECTONOPHYSICS,475(3-4).
MLA	Wang, Shifeng,et al."New radiometric dating constrains the time for initiation of the Karakorum fault zone (KFZ), SW Tibet".TECTONOPHYSICS 475.3-4(2009).