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DOI	10.1016/j.tecto.2022.229378
	Spatially focused erosion in the High Himalaya and the geometry of the Main Himalayan Thrust in Central Nepal (85 degrees E) from thermo-kinematic modeling of thermochronological data in the Gyirong region (southern China)
	Wolff, Reinhard; Hoelzer, Kyra; Hetzel, Ralf; Xu, Qiang; Dunkl, Istvan; Anczkiewicz, Aneta A.; Li, Zhenyu
通讯作者	Wolff, R (通讯作者)
发表日期	2022
ISSN	0040-1951
EISSN	1879-3266
卷号	834
英文摘要	The subsurface structure of the Himalaya is dominated by the seismically active Main Himalayan Thrust fault, which accommodates about half of the plate convergence between India and Asia. In Central Nepal, geological, geophysical, and geodetic studies indicate that the Main Himalayan Thrust has a flat-ramp-flat geometry, which causes cooling, erosion, and exhumation of rocks to be faster above the mid-crustal ramp than above the adjacent upper and lower flats. However, in the northern High Himalaya the ramp geometry, in particular its width and depth are not well resolved. To place further constraints on the northward extent and depth of the ramp, we present for the first time low-temperature thermochronological data and U-Pb zircon ages from the Gyimng region, China (northern High Himalaya). Our zircon U-Pb data show that the protolith of the High Himalayan orthogneisses is 478 +/- 4 Ma old, and was intruded by a large leucogranite at 19.5 +/- 0.7 Ma. The Pliocene-Quaternary cooling of the study area is constrained by apatite fission track ages and apatite and zircon (U-Th)/He ages between similar to 5 Ma and similar to 0.5 Ma, which show a marked trend of southward-younging ages. Together with published cooling ages from Nepal farther south, the ages define a U-shaped pattern across the Main Himalayan Thrust, with ages increasing to the north and south from a minimum in the High Himalaya. A thermokinematic model, in which the geometry of the mid-crustal ramp was varied, explains the age data and suggests that the ramp has a dip of similar to 22 degrees N. Compared to previous models, our new ages require that the ramp has a greater width (similar to 55 km) and reaches a greater depth (similar to 34 km) below the northern High Himalaya. Still farther north, the fault is presumably developed as a gently-dipping ductile shear zone, which forms the prominent reflector visible in seismic reflection data.
关键词	NEIGHBORHOOD ALGORITHM GEOPHYSICAL INVERSION EPISODIC EXHUMATION TECTONIC EVOLUTION RADIATION-DAMAGE HELIUM DIFFUSION COLLISION ZONE U-PB GORKHA ZIRCON
英文关键词	Himalaya; Main Himalayan Thrust; Gyirong region; Thermochronology; Thermo-kinematic modeling
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000798946900003
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/260738
推荐引用方式 GB/T 7714	Wolff, Reinhard,Hoelzer, Kyra,Hetzel, Ralf,et al. Spatially focused erosion in the High Himalaya and the geometry of the Main Himalayan Thrust in Central Nepal (85 degrees E) from thermo-kinematic modeling of thermochronological data in the Gyirong region (southern China)[J]. 中国科学院青藏高原研究所,2022,834.
APA	Wolff, Reinhard.,Hoelzer, Kyra.,Hetzel, Ralf.,Xu, Qiang.,Dunkl, Istvan.,...&Li, Zhenyu.(2022).Spatially focused erosion in the High Himalaya and the geometry of the Main Himalayan Thrust in Central Nepal (85 degrees E) from thermo-kinematic modeling of thermochronological data in the Gyirong region (southern China).TECTONOPHYSICS,834.
MLA	Wolff, Reinhard,et al."Spatially focused erosion in the High Himalaya and the geometry of the Main Himalayan Thrust in Central Nepal (85 degrees E) from thermo-kinematic modeling of thermochronological data in the Gyirong region (southern China)".TECTONOPHYSICS 834(2022).