Skip to Main Content
GEOREF RECORD

Holocene and modern sediment budgets for the Ganges-Brahmaputra river system; evidence for highstand dispersal to flood-plain, shelf, and deep-sea depocenters

Steven L. Goodbred and Steven A. Kuehl
Holocene and modern sediment budgets for the Ganges-Brahmaputra river system; evidence for highstand dispersal to flood-plain, shelf, and deep-sea depocenters
Geology (Boulder) (June 1999) 27 (6): 559-562

Abstract

The partitioning of fluvial sediment load across continental margins is an important control on strata formation and sequence development; however, few quantitative sediment budgets that encompass entire dispersal systems exist. For the Ganges-Brahmaputra river system, sediment discharge is estimated to be 10 (super 9) t/yr at gauging stations approximately 300 km inland of the coast, but little has been known of the downstream fate of this material. Geochronological, geophysical, and stratigraphic investigations of the lowland flood plain, delta plain, and shelf help to delineate the extent of Holocene fill and allow calculation of a first-order sediment budget. Results reveal that 1500 X 10 (super 9) m (super 3) of sediment fill has been sequestered within the flood plain and delta plain since ca. 7000 yr B.P., or about one-third of the annual discharge. The remaining load appears to be apportioned between the prograding subaqueous delta (1970X10 (super 9) m (super 3) ) and transport to the deep-sea Bengal fan via a nearshore canyon. Modern (<100 yr) budget estimates based on short-term accretion rates indicate a similar dispersal pattern and show that contemporaneous deposition continues within these disparate depocenters. The roughly equal partitioning of sediment among flood-plain, shelf, and deep-sea settings reflects the respective influence of an inland tectonic basin, a wide shelf, and a deeply incised canyon system. The findings also support new sequence stratigraphic models for these settings and indicate the important insight that modern river deltas can provide for ancient margin systems. Furthermore, results affirm that values of riverine sediment flux to the oceans may be considerably overestimated by not accounting for loss to the flood plains downstream of the gauging stations.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 27
Serial Issue: 6
Title: Holocene and modern sediment budgets for the Ganges-Brahmaputra river system; evidence for highstand dispersal to flood-plain, shelf, and deep-sea depocenters
Affiliation: College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA, United States
Pages: 559-562
Published: 199906
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
Accession Number: 1999-037312
Categories: Quaternary geology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables
N23°34'60" - N29°49'60", E89°40'00" - E95°25'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 199913
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal