DOI: 10.1016/j.epsl.2020.116347
论文题名: Crustal tilting and differential exhumation of Gangdese Batholith in southern Tibet revealed by bedrock pressures
作者: Cao W. ; Yang J. ; Zuza A.V. ; Ji W.-Q. ; Ma X.-X. ; Chu X. ; Burgess Q.P.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 543 语种: 英语
中文关键词: crustal tilting
; exhumation
; Gangdese Batholith
; pluton emplacement depth
; southern Tibet
英文关键词: Binary alloys
; Lead alloys
; Metamorphic rocks
; Silicate minerals
; Tectonics
; Zircon
; Continent-continent collisions
; Continental crusts
; Natural laboratories
; Pluton emplacement
; Surface erosion rate
; Surface process
; Tectonic events
; U-Pb zircon ages
; Uranium alloys
; batholith
; bedrock
; crustal deformation
; exhumation
; magmatism
; tectonic evolution
; tectonic setting
; tilt
; uranium-lead dating
; zircon
; China
; Xizang
英文摘要: The exhumation history of the Gangdese Batholith, southern Tibet, bears on how magmatism and tectonism interact with surface processes in a long-lived magmatic orogen. In this study, we applied Al-in-hornblende barometry across the eastern Gangdese Batholith to obtain pluton emplacement pressures. Our results, together with existing bedrock pressure data, reveal the regional paleo-depth pattern across the Gangdese Batholith. The western part of the batholith, near Lhasa, exposes plutons emplaced at 1-2 kbar whereas the eastern part, near Nyingchi, exposes crust recording pressures typically of 6-12 kbar. We coupled pressure data with new and published U-Pb zircon ages to constrain the exhumation history of the Gangdese Batholith. The results show that since 100 Ma, the upper crust experienced limited exhumation except a pronounced Oligocene-Miocene pulse. In contrast, the middle-lower crust experienced a complex exhumation and burial history, reflecting major tectonic events including the development of continental arc and continent-continent collision. Since ca. 10 Ma, the eastern Nyingchi sector experienced fast exhumation (total exhumation > 40 km), which was likely related to the exhumation of the Eastern Himalayan Syntaxis. The Lhasa sector experienced comparatively limited exhumation (total exhumation < 10 km). Such dramatic differential exhumation along the E-W direction requires that the Gangdese Batholith was tilted to present-day exposure levels. Our study shows that during the evolution of a magmatic orogen, the upper and middle-lower crust can behave differently, and the exhumation history reflects integrated tectonic, magmatic, and surface processes. The surface erosion rate estimates can be used to calculate CO2 consumption and evaluate the roles of magmatic orogens in the long-term carbon cycle. Given its great exposures of plutonic and metamorphic rocks across a relatively continuous crustal section, the Gangdese Batholith has great potential to serve as a natural laboratory to understand the structures and evolution of the continental crust. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164900
Appears in Collections: 气候变化与战略
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作者单位: Department of Geological Sciences and Engineering, University of Nevada, Reno, MS-172, 1664 N. Virginia St., Reno, NV 89557, United States; Nevada Bureau of Mines and Geology, University of Nevada, Reno, MS-178, 1664 N. Virginia St., Reno, NV 89557, United States; State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing, 100029, China; Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, China; Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, Ontario M5S3B1, Canada
Recommended Citation:
Cao W.,Yang J.,Zuza A.V.,et al. Crustal tilting and differential exhumation of Gangdese Batholith in southern Tibet revealed by bedrock pressures[J]. Earth and Planetary Science Letters,2020-01-01,543