气候变化领域集成服务门户(CCPortal): Evidence of episodically accelerated denudation on the Namche Barwa massif by megafloods

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DOI	10.1016/j.quascirev.2020.106410
	Evidence of episodically accelerated denudation on the Namche Barwa massif by megafloods
	Borgohain B.; Mathew G.; Chauhan N.; Jain V.; Singhvi A.K.
发表日期	2020
ISSN	0277-3791
卷号	245
英文摘要	Megafloods cause widespread mobilization of sediments that have strong potential to control the geodynamic evolution of the Namche Barwa (NB) massif by changing the landscape morphology within a short time. However, the impact of catastrophic events on the denudation of the massif over the longer time scale has not been explored in detail. This contribution assesses the impact of catastrophic floods on the denudation style of the Namche Barwa (NB) massif over millennial time scales. Towards this, 21 optical ages and ∼1700 detrital thermochronometric ages of zircon and apatite minerals extracted from paleoflood sediments downstream of the massif, were integrated with decadal sediment load and aggradation data to estimate the minimum denudation rate during paleoflood events. The results indicate that the 7 ka flood eroded ∼71 m of material from the NB massif. This denudation is equivalent to the material that would be produced over ∼8000 years of erosion at a rate of ∼9 mm/a. The 3.5 ka flood eroded ∼24 m of material equaling ∼2500 years worth of erosion at a rate of ∼9 mm/a. Such relatively instantaneous denudations are three orders of magnitude higher than averaged denudation rates over million-year time scale. This study, therefore, provides the first evidence of the strong interplay of catastrophic flood events and tectonics for the rapid exhumation of the Namche Barwa massif. Megafloods from the failure of dammed lakes provide valuable information to understand the flood surge risk for human settlements in the Siang and the Assam valleys. © 2020 Elsevier Ltd
英文关键词	Denudation; Detrital fission track dating; Eastern Himalayan syntaxis; Optically stimulated luminescence dating; Paleoflood deposits; Paleohydrology; Quaternary
语种	英语
scopus关键词	Erosion; Geodynamics; Phosphate minerals; Sediments; Silicate minerals; Time measurement; Zircon; Catastrophic event; Catastrophic floods; Denudation rates; Flood surge; Geodynamic evolution; Human settlements; Sediment loads; Three orders of magnitude; Floods; apatite; catastrophic event; geodynamics; human settlement; paleoflood; thermochronology; China; Himalayas; Namjagbarwa Feng; Xizang
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151339
作者单位	Department of Earth Sciences, Indian Institute of Technology, Bombay, Mumbai, 400076, India; Atomic, Molecular, and Optical Physics Division, Physical Research Laboratory, Ahmedabad, 380009, India; Earth Sciences Department, Indian Institute of Technology, Gandhinagar, 382355, India
推荐引用方式 GB/T 7714	Borgohain B.,Mathew G.,Chauhan N.,et al. Evidence of episodically accelerated denudation on the Namche Barwa massif by megafloods[J],2020,245.
APA	Borgohain B.,Mathew G.,Chauhan N.,Jain V.,&Singhvi A.K..(2020).Evidence of episodically accelerated denudation on the Namche Barwa massif by megafloods.Quaternary Science Reviews,245.
MLA	Borgohain B.,et al."Evidence of episodically accelerated denudation on the Namche Barwa massif by megafloods".Quaternary Science Reviews 245(2020).