DOI: 10.1016/j.epsl.2017.10.036
Scopus记录号: 2-s2.0-85033706474
论文题名: Pliocene episodic exhumation and the significance of the Munsiari thrust in the northwestern Himalaya
作者: Stübner K. ; Grujic D. ; Dunkl I. ; Thiede R. ; Eugster P.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 481 起始页码: 273
结束页码: 283
语种: 英语
英文关键词: Himachal Pradesh
; Himalaya
; Munsiari thrust
; Pliocene
; thermochronology
; thermokinematic modelling
Scopus关键词: Deformation
; Silicate minerals
; Zircon
; Himachal Pradesh
; Himalayas
; Munsiari thrust
; Pliocene
; Thermochronology
; Tectonics
; deformation
; episodic event
; exhumation
; Pliocene
; tectonics
; thermochronology
; thrust
; zircon
; Himachal Pradesh
; Himalayas
; India
英文摘要: The Himalayan thrust belt comprises three in-sequence foreland-propagating orogen-scale faults, the Main Central thrust, the Main Boundary thrust, and the Main Frontal thrust. Recently, the Munsiari–Ramgarh–Shumar thrust system has been recognized as an additional, potentially orogen-scale shear zone in the proximal footwall of the Main Central thrust. The timing of the Munsiari, Ramgarh, and Shumar thrusts and their role in Himalayan tectonics are disputed. We present 31 new zircon (U–Th)/He ages from a profile across the central Himachal Himalaya in the Beas River area. Within a ∼40 km wide belt northeast of the Kullu–Larji–Rampur window, ages ranging from 2.4±0.4 Ma to 5.4±0.9 Ma constrain a distinct episode of rapid Pliocene to Present exhumation; north and south of this belt, zircon (U–Th)/He ages are older (7.0±0.7 Ma to 42.2±2.1 Ma). We attribute the Pliocene rapid exhumation episode to basal accretion to the Himalayan thrust belt and duplex formation in the Lesser Himalayan sequence including initiation of the Munsiari thrust. Pecube thermokinematic modelling suggests exhumation rates of ∼2–3 mm/yr from 4–7 to 0 Ma above the duplex contrasting with lower (<0.3 mm/yr) middle-late Miocene exhumation rates. The Munsiari thrust terminates laterally in central Himachal Pradesh. In the NW Indian Himalaya, the Main Central thrust zone comprises the sheared basal sections of the Greater Himalayan sequence and the mylonitic ‘Bajaura nappe’ of Lesser Himalayan affinity. We correlate the Bajaura unit with the Ramgarh thrust sheet in Nepal based on similar lithologies and the middle Miocene age of deformation. The Munsiari thrust in the central Himachal Himalaya is several Myr younger than deformation in the Bajaura and Ramgarh thrust sheets. Our results illustrate the complex and segmented nature of the Munsiari–Ramgarh–Shumar thrust system. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110171
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Geosciences, Eberhard Karls Universität Tübingen, Tübingen, 72074, Germany; Sedimentology and Environmental Geology, Geoscience Center, University of Göttingen, Göttingen, 37077, Germany; Department of Earth Sciences, Dalhousie University, Halifax, NS B3H 4J1, Canada; Institute of Earth and Environmental Sciences, University of Potsdam, Potsdam, 14476, Germany
Recommended Citation:
Stübner K.,Grujic D.,Dunkl I.,et al. Pliocene episodic exhumation and the significance of the Munsiari thrust in the northwestern Himalaya[J]. Earth and Planetary Science Letters,2018-01-01,481