气候变化领域集成服务门户(CCPortal): The South Tibet detachment shear zone in the Dinggye area Time constraints on extrusion models of the Himalayas

CCPortal

DOI	10.1016/j.epsl.2009.12.035
	The South Tibet detachment shear zone in the Dinggye area Time constraints on extrusion models of the Himalayas
	Leloup, P. H.; Maheo, G.; Arnaud, N.; Kali, E.; Boutonnet, E.; Liu, Dunyi; Liu Xiaohan; Li Haibing
通讯作者	Leloup, PH (通讯作者)
发表日期	2010
ISSN	0012-821X
起始页码	1
结束页码	16
卷号	292 期号:1-2
英文摘要	We investigate the timing of end of motion along the South Tibet Detachment System (STDS), a major normal fault system that runs parallel to the Himalayan range for more than 1500 km. Near Dinggye (similar to 28 degrees 10'N, 87 degrees 40'E), the STD dips similar to 10 +/- 5 degrees to the North and separates Paleozoic Tethyan series from Upper Himalayan Crystalline Series (UHCS). Immediately below the STD, the UHCS is highly deformed in the STD shear zone, lineations trend NNE and the shear senses are top to the NE. In micaschist, the P-T path constrained by pseudosection and garnet chemistry, shows successive metamorphic conditions of similar to 0.6 GPa and similar to 550 degrees C and 0.5 GPa and 625 degrees C. U/Pb dating of monazites and zircons in deformed and undeformed leucogranites suggests that ductile deformation lasted until at least similar to 16 Ma but ended prior to similar to 15 Ma in the STD shear zone similar to 100 m below the detachment. Ar/Ar micas ages in the footwall span between similar to 14.6 and 13.6 Ma, indicating rapid cooling down to similar to 320 degrees C, and suggesting persistence of normal faulting, at that time. The STDS is cut and offset by the N-S trending Dinggye active normal fault which initiated prior to 11 Ma thus providing a minimum bound for the end of STDS motion. These data are interpreted as reflecting 0.3 GPa (11 km) to 0.6 GPa (22 km) of exhumation along the STDS starting prior to similar to 16 Ma, ending between 13.6 and 11 Ma. The 1000 km long stretch of the STDS east of the Gurla Mandata probably stopped almost synchronously between 13 and 11 Ma ago, coevally with a sudden switch from NNE-SSW to E-W extension at the top of the accretionary prism, with a jump of the major thrust from the lower Main Central Thrust (MCTI) to the Main Boundary Thrust (MBT), and with a change in the India and Asia convergence direction. This synchronism is probably better explained in the frame of a thrust wedge or thrust system model than a lower channel flow model. West of the Gurla Mandata the STDS appears to stop 5 to 3 Ma earlier, possibly related to local interactions with the Karakorum fault in a way that needs to be understood. (c) 2009 Elsevier B.V. All rights reserved.
关键词	MAIN CENTRAL THRUST CENTRAL NEPAL HIMALAYA EAST-WEST EXTENSION TECTONIC EVOLUTION KARAKORAM FAULT METAMORPHIC SEQUENCE THAKKHOLA GRABEN EXHUMATION SYSTEM DEFORMATION
英文关键词	Himalaya; South Tibet Detachment System; chronology; extrusion
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000276138900001
来源期刊	EARTH AND PLANETARY SCIENCE LETTERS
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/257835
推荐引用方式 GB/T 7714	Leloup, P. H.,Maheo, G.,Arnaud, N.,et al. The South Tibet detachment shear zone in the Dinggye area Time constraints on extrusion models of the Himalayas[J]. 中国科学院青藏高原研究所,2010,292(1-2).
APA	Leloup, P. H..,Maheo, G..,Arnaud, N..,Kali, E..,Boutonnet, E..,...&Li Haibing.(2010).The South Tibet detachment shear zone in the Dinggye area Time constraints on extrusion models of the Himalayas.EARTH AND PLANETARY SCIENCE LETTERS,292(1-2).
MLA	Leloup, P. H.,et al."The South Tibet detachment shear zone in the Dinggye area Time constraints on extrusion models of the Himalayas".EARTH AND PLANETARY SCIENCE LETTERS 292.1-2(2010).