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

1999; Geological Society of America; Volume: 27; Issue: 6 Linguagem: Inglês

10.1130/0091-7613(1999)027 2.3.co;2

1943-2682

S. L. Goodbred, Steven A. Kuehl,

Geology and Paleoclimatology Research

Research Article| June 01, 1999 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, Jr; Steven L. Goodbred, Jr 1Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia 23062, USA Search for other works by this author on: GSW Google Scholar Steven A. Kuehl Steven A. Kuehl 1Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia 23062, USA Search for other works by this author on: GSW Google Scholar Geology (1999) 27 (6): 559–562. https://doi.org/10.1130/0091-7613(1999)027 2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Steven L. Goodbred, 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 1999;; 27 (6): 559–562. doi: https://doi.org/10.1130/0091-7613(1999)027 2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search 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 109 t/yr at gauging stations ∼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 × 109 m3 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 (1970 × 109 m3) 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. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.