Skip to main content

Research Repository

Advanced Search

Sediment storage and release from Himalayan piggyback basins and implications for downstream river morphology and evolution

Densmore, A.L.; Sinha, R.; Sinha, S.; Tandon, S.K.; Jain, V.

Sediment storage and release from Himalayan piggyback basins and implications for downstream river morphology and evolution Thumbnail


Authors

R. Sinha

S. Sinha

S.K. Tandon

V. Jain



Abstract

Piggyback basins developed at the mountain fronts of collisional orogens can act as important, and transient, sediment stores along major river systems. It is not clear, however, how the storage and release of sediment in piggyback basins affects the sediment flux and evolution of downstream river reaches. Here we investigate the timing and volumes of sediment storage and release in the Dehra Dun, a piggyback basin developed along the Himalayan mountain front in northwestern India. Based on OSL dating, we show evidence for three major phases of aggradation in the dun, bracketed at ~41-33 ka, 34-21 ka, and 23-10 ka, each accompanied by progradation of sediment fans into the dun. Each of these phases was followed by backfilling and (apparently) rapid fan-head incision, leading to abandonment of the depositional unit and a basinward shift of the active depocentre. Excavation of dun sediment after the second and third phases of aggradation produced time-averaged sediment discharges that were ~1-2% of the modern suspended-sediment discharges of the Ganga and Yamuna rivers that traverse the margins of the dun; this sediment is derived from catchment areas that together comprise 1.5% of the drainage area of these rivers. Comparison of the timing of dun storage and release with upstream and downstream records of incision and aggradation in the Ganga show that sediment storage in the dun generally coincides with periods of widespread hinterland aggradation but that late stages of dun aggradation, and especially times of dun sediment excavation, coincide with major periods of sediment export to the Ganga Basin. The dun thus acts to amplify temporal variations in hinterland sediment supply or transport capacity. This conceptual model appears to explain morphological features of other major river systems along the Himalayan front, including the Gandak and Kosi Rivers, and may be important for understanding sediment flux variations in other collisional mountain belts.

Citation

Densmore, A., Sinha, R., Sinha, S., Tandon, S., & Jain, V. (2016). Sediment storage and release from Himalayan piggyback basins and implications for downstream river morphology and evolution. Basin Research, 28(4), 446-461. https://doi.org/10.1111/bre.12116

Journal Article Type Article
Acceptance Date Jan 16, 2015
Online Publication Date Mar 6, 2015
Publication Date Aug 1, 2016
Deposit Date Jan 22, 2015
Publicly Available Date Mar 29, 2024
Journal Basin Research
Print ISSN 0950-091X
Electronic ISSN 1365-2117
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 28
Issue 4
Pages 446-461
DOI https://doi.org/10.1111/bre.12116
Keywords Himalayas, Ganga River basin, Sediment transport, Sediment storage, Erosion, Intermontane valley.

Files

Accepted Journal Article (19.4 Mb)
PDF

Copyright Statement
This is the accepted version of the following article: Densmore, A. L., Sinha, R., Sinha, S., Tandon, S. K. and Jain, V. (2016), Sediment storage and release from Himalayan piggyback basins and implications for downstream river morphology and evolution. Basin Research, 28(4): 446-461, which has been published in final form at http://dx.doi.org/10.1111/bre.12116. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.





You might also like



Downloadable Citations