气候变化领域集成服务门户(CCPortal): Kinematic evolution of a continental collision: Constraining the Himalayan-Tibetan orogen via bulk strain rates

CCPortal

DOI	10.1016/j.tecto.2020.228642
	Kinematic evolution of a continental collision: Constraining the Himalayan-Tibetan orogen via bulk strain rates
	Zuza, Andrew, V; Gavillot, Yann; Haproff, Peter J.; Wu, Chen
通讯作者	Zuza, AV (通讯作者)
发表日期	2020
ISSN	0040-1951
EISSN	1879-3266
卷号	797
英文摘要	We investigated temporal variations of the bulk strain rate across the Himalayan-Tibetan orogen, which impact the magnitudes, rates, and distribution of deformation across the orogen. The present-day strain rate estimated from geodesy is similar to 5-6x10(-16) s(-1) and estimation of past rates depends on the orogenic shortening rate and effective orogen width. Plate-circuit reconstructions provide constraints on time-varying India-Asia convergence rates, showing a marked deceleration since initial collision at ca. 58 Ma. Geologic evidence suggests that most of the Tibetan crust started deforming shortly after initial collision, which simplifies estimation of the initial orogen width. We examined several kinematic models: (1) Greater Indian and Tibetan crust started deforming immediately after collision, (2) only Tibetan crust deformed initially, (3) plate convergence was decoupled from crustal shortening, with Tibetan crust deforming slower than plate rates, or (4) a hard India-Asia collision at ca. 45 Ma following closure of the Xigaze backarc. Models 1, 3, and 4 yield early Cenozoic bulk strain rates that match present-day rates (5-6x10(-16) s(-1)), whereas Model 2 yields faster rates (1.2x10(-15) s(-1)) that must have decreased through time to avoid shortening exceeding total plate convergence. Using these bounds, we constrain crustal shortening across the entire orogen and along its southern and northern margins, defined by the Himalaya and Qilian Shan, respectively. Application of these models to Tibetan crustal thickening suggests that the plateau reached its present-day value (similar to 70 km) by ca. 15 Ma, which corresponds to the onset of lateral deformation (e.g., strike-slip and normal faulting). Lateral deformation in the Himalayan-Tibetan orogen may have resulted from progressive crustal thickening and reorientation of the intermediate principal stress axis. At the thrust-belt scale, our modeling yields shortening rates and magnitudes that match geologic observations. This approach provides testable external kinematic constraints to guide future geological and geophysical investigations.
关键词	CENOZOIC TECTONIC EVOLUTION APATITE FISSION-TRACK INDIA-ASIA COLLISION FOLD-THRUST BELT EASTERN QILIAN SHAN STRIKE-SLIP FAULTS COOLING HISTORY CONTINUOUS DEFORMATION GEOLOGICAL EVOLUTION NORTHEASTWARD GROWTH
英文关键词	Himalaya-Tibetan orogen; Shortening strain rate; Crustal thickening; GPS data
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000596071500001
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/260036
推荐引用方式 GB/T 7714	Zuza, Andrew, V,Gavillot, Yann,Haproff, Peter J.,et al. Kinematic evolution of a continental collision: Constraining the Himalayan-Tibetan orogen via bulk strain rates[J]. 中国科学院青藏高原研究所,2020,797.
APA	Zuza, Andrew, V,Gavillot, Yann,Haproff, Peter J.,&Wu, Chen.(2020).Kinematic evolution of a continental collision: Constraining the Himalayan-Tibetan orogen via bulk strain rates.TECTONOPHYSICS,797.
MLA	Zuza, Andrew, V,et al."Kinematic evolution of a continental collision: Constraining the Himalayan-Tibetan orogen via bulk strain rates".TECTONOPHYSICS 797(2020).