气候变化领域集成服务门户(CCPortal): Monsoon controls on sediment generation and transport: Mass budget and provenance constraints from the Indus River catchment, delta and submarine fan over tectonic and multimillennial timescales

CCPortal

DOI	10.1016/j.earscirev.2021.103682
	Monsoon controls on sediment generation and transport: Mass budget and provenance constraints from the Indus River catchment, delta and submarine fan over tectonic and multimillennial timescales
	Clift P.D.; Jonell T.N.
发表日期	2021
ISSN	00128252
卷号	220
英文摘要	How well do deep-sea sedimentary archives track erosion in upland sources, driven by climatic change or tectonic forcing? Located on the western edge of South Asian monsoon influence, the Indus River system is particularly sensitive to variations in monsoon rainfall and thus provides a unique opportunity to estimate the nature of sedimentary signal propagation (i.e., recognizable pulses of sediment) through a large river basin under different climatic conditions. In this review we examine the impact that changing monsoon rainfall has had on NW Himalayan landscapes and its foreland since the middle Miocene. Rates of erosion are linked to summer monsoon rains over tectonic timescales but patterns of erosion are more explicitly linked to tectonically-driven rock uplift. Positive feedback between rock uplift and orographic precipitation drives increased erosion and transport from the Lesser Himalaya since the Miocene. After 2 Ma, erosion increasingly shifts to the Inner Lesser Himalaya. As defined multiproxy evidence, strong monsoon rainfall intervals broadly result in increased erosion and faster sediment transport together with increased chemical weathering, although the latter is further linked with global temperature and to the magnitude of sediment recycling within the routing system. We estimate that during the Holocene, most sediment (67–89% of the total ~6000 km3 or 16.3 x 1012 t) delivered to the ocean was sourced either from direct bedrock erosion through channel incision linked to higher discharge or from remobilized, recycled glacial sediment initially deposited during the Last Glacial Maximum (LGM). Post-LGM sediment is primarily stored within the delta plain and shelf clinoform systems. Over the last 14 kyr, average mass delivery rates (936–1404 Mt/y) are much higher than pre-damming estimates (pre-1940s; 250–300 Mt/y). To reconcile observations with pre-damming estimates, high sediment supply rates, probably during strong monsoon intervals over the early Holocene, are required. Long-term rates were high (182273 Mt/y) during a middle Miocene strong monsoon interval. Quaternary Indus submarine fan sedimentation is limited to sea level lowstands, at which times shelf and delta sediment is eroded and reworked into deep water. As a result, and for at least the past 2–3 m.y., most sediment delivered to the Indus submarine fan was initially eroded from bedrock during strong summer monsoon intervals but deposited into the fan under weak monsoon intervals. During the most recent sea level lowstand, only ~24% of sediment deposited in the fan was derived from synchronous onshore bedrock erosion, with the remaining accounted for by recycled terrace, floodplain and shelf clinoform system sediment. Variations in monsoon intensity over the last glacial cycle strongly impact the locus of onshore erosion, with increased relative Himalayan bedrock erosion during times of strong, wet monsoon intervals and increased Karakoram bedrock erosion during drier glacial intervals. © 2021 Elsevier B.V.
关键词	Erosion Himalaya Indus Monsoon Transport
英文关键词	bedrock; catchment; delta; erosion rate; fluvial deposit; Miocene; monsoon; provenance; sediment transport; submarine fan; tectonic setting; timescale; Himalayas; Indus River; Lesser Himalayas
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203991
作者单位	Department of Geology and Geophysics, E235 Howe-Russell, Louisiana State University, Baton Rouge, LA 70803, United States; Research Center for Earth System Science, Yunnan University, Kunming, Yunnan Province 650091, China; School of Earth and Environmental Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia
推荐引用方式 GB/T 7714	Clift P.D.,Jonell T.N.. Monsoon controls on sediment generation and transport: Mass budget and provenance constraints from the Indus River catchment, delta and submarine fan over tectonic and multimillennial timescales[J],2021,220.
APA	Clift P.D.,&Jonell T.N..(2021).Monsoon controls on sediment generation and transport: Mass budget and provenance constraints from the Indus River catchment, delta and submarine fan over tectonic and multimillennial timescales.Earth Science Reviews,220.
MLA	Clift P.D.,et al."Monsoon controls on sediment generation and transport: Mass budget and provenance constraints from the Indus River catchment, delta and submarine fan over tectonic and multimillennial timescales".Earth Science Reviews 220(2021).