DOI: 10.1007/s00531-013-0904-6
Scopus记录号: 2-s2.0-84884417915
论文题名: Thermal metamorphism of the Arunachal Himalaya, India: Raman thermometry and thermochronological constraints on the tectono-thermal evolution
作者: Mathew G. ; De Sarkar S. ; Pande K. ; Dutta S. ; Ali S. ; Rai A. ; Netrawali S.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2013
卷: 102, 期: 7 起始页码: 1911
结束页码: 1936
语种: 英语
英文关键词: Channel flow
; Geothermometer
; Himalaya
; Inverted metamorphism
; RSCM
; Thermochronology
Scopus关键词: channel flow
; exhumation
; footwall
; geothermometry
; metamorphism
; P-T conditions
; P-T-t path
; Raman spectroscopy
; tectonic evolution
; thermal evolution
; thermochronology
; unroofing
; Arunachal Pradesh
; Himalayas
; India
; Lesser Himalayas
; Main Central Thrust Zone
; Metamorpha
英文摘要: Determination of the peak thermal condition is vital in order to understand tectono-thermal evolution of the Himalayan belt. The Lesser Himalayan Sequence (LHS) in the Western Arunachal Pradesh, being rich in carbonaceous material (CM), facilitates the determination of peak metamorphic temperature based on Raman spectroscopy of carbonaceous material (RSCM). In this study, we have used RSCM method of Beyssac et al. (J Metamorph Geol 20:859-871, 2002a) and Rahl et al. (Earth Planet Sci Lett 240:339-354, 2005) to estimate the thermal history of LHS and Siwalik foreland from the western Arunachal Pradesh. The study indicates that the temperature of 700-800 °C in the Greater Himalayan Sequence (GHS) decreases to 650-700 °C in the main central thrust zone (MCTZ) and decreases further to <200 °C in the Mio-Pliocene sequence of Siwaliks. The work demonstrates greater reliability of Rahl et al.'s (Earth Planet Sci Lett 240:339-354, 2005) RSCM method for temperatures >600 and <340 °C. We show that the higher and lower zones of Bomdila Gneiss (BG) experienced temperature of ~600 °C and exhumed at different stages along the Bomdila Thrust (BT) and Upper Main Boundary Thrust (U.MBT). Pyrolysis analysis of the CM together with the Fission Track ages from upper Siwaliks corroborates the RSCM thermometry estimate of ~240 °C. The results indicate that the Permian sequence north of Lower MBT was deposited at greater depths (>12 km) than the upper Siwalik sediments to its south at depths <8 km before they were exhumed. The 40Ar/39Ar ages suggest that the upper zones of Se La evolved ~13-15 Ma. The middle zone exhumed at ~11 Ma and lower zone close to ~8 Ma indicating erosional unroofing of the MCT sheet. The footwall of MCTZ cooled between 6 and 8 Ma. Analyses of P-T path imply that LHS between MCT and U.MBT zone falls within the kyanite stability field with near isobaric condition. At higher structural level, the temperatures increase gradually with P-T conditions in the sillimanite stability field. The near isothermal (700-800 °C) condition in the GHS, isobaric condition in the MCTZ together with T-t path evidence of GHS that experienced relatively longer duration of near peak temperatures and rapid cooling towards MCTZ, compares the evolution of GHS and inverted metamorphic gradient closely to channel flow predictions. © 2013 Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884417915&doi=10.1007%2fs00531-013-0904-6&partnerID=40&md5=c4c1a2986ab9949943f90dd27eefbfda
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70502
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Earth Sciences, Indian Institute of Technology (IIT) Bombay, Powai, Mumbai, 400 076 Maharashtra, India
Recommended Citation:
Mathew G.,De Sarkar S.,Pande K.,et al. Thermal metamorphism of the Arunachal Himalaya, India: Raman thermometry and thermochronological constraints on the tectono-thermal evolution[J]. International Journal of Earth Sciences,2013-01-01,102(7)