Controls on gravel termination in seven distributary channels of the Selenga River Delta, Baikal Rift basin, Russia

Research Article| July 01, 2016 Controls on gravel termination in seven distributary channels of the Selenga River Delta, Baikal Rift basin, Russia Tian Y. Dong; Tian Y. Dong † 1Department of Earth Science, Rice University, MS-126, 6100 Main Street, Houston, Texas 77005, USA †td10@rice.edu Search for other works by this author on: GSW Google Scholar Jeffrey A. Nittrouer; Jeffrey A. Nittrouer 1Department of Earth Science, Rice University, MS-126, 6100 Main Street, Houston, Texas 77005, USA Search for other works by this author on: GSW Google Scholar Elena Il'icheva; Elena Il'icheva 2Laboratory of Hydrology and Climatology, V.B. Sochava Institute of Geography, Siberian Branch Russian Academy of Science (SB RAS), Ulan-Batorskaya Street, Irkutsk, 664033, Russian Federation Search for other works by this author on: GSW Google Scholar Maksim Pavlov; Maksim Pavlov 2Laboratory of Hydrology and Climatology, V.B. Sochava Institute of Geography, Siberian Branch Russian Academy of Science (SB RAS), Ulan-Batorskaya Street, Irkutsk, 664033, Russian Federation Search for other works by this author on: GSW Google Scholar Brandon McElroy; Brandon McElroy 3Department of Geology and Geophysics, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Matthew J. Czapiga; Matthew J. Czapiga 4Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, Illinois 61801, USA Search for other works by this author on: GSW Google Scholar Hongbo Ma; Hongbo Ma 1Department of Earth Science, Rice University, MS-126, 6100 Main Street, Houston, Texas 77005, USA Search for other works by this author on: GSW Google Scholar Gary Parker Gary Parker 4Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, Illinois 61801, USA5Department of Geology, University of Illinois at Urbana-Champaign, 605 East Springfield Avenue, Champaign, Illinois 61820, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2016) 128 (7-8): 1297–1312. https://doi.org/10.1130/B31427.1 Article history received: 17 Sep 2015 rev-recd: 13 Jan 2016 accepted: 08 Feb 2016 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Tian Y. Dong, Jeffrey A. Nittrouer, Elena Il'icheva, Maksim Pavlov, Brandon McElroy, Matthew J. Czapiga, Hongbo Ma, Gary Parker; Controls on gravel termination in seven distributary channels of the Selenga River Delta, Baikal Rift basin, Russia. GSA Bulletin 2016;; 128 (7-8): 1297–1312. doi: https://doi.org/10.1130/B31427.1 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 SocietyGSA Bulletin Search Advanced Search Abstract The Selenga River Delta, Lake Baikal, Russia, is ∼600 km2 in size and contains multiple distributary channels that receive varying amounts of water and sediment discharge. The delta is positioned along the deep-water (∼1600 m) margin of Lake Baikal, a half-graben–styled rift basin, qualifying it as a modern analogue of a shelf-edge delta system. This study provides a detailed field survey of channel bed sediment composition, channel geometry, and water discharge. The data and analyses presented here indicate that the Selenga Delta exhibits downstream sediment fining over tens of kilometers, ranging from predominantly gravel (coarse pebble) and sand near its apex to silt and sand at the delta-lake interface. We developed an analytical framework to evaluate the downstream elimination of gravel within the multiple distributary channels. The findings include the following. (1) The Selenga River Delta consists of at least eight orders of distributary channels. (2) With increasing channel order downstream, channel cross-sectional area, width-depth ratio, water discharge, boundary shear stress, and sediment flux systematically decrease. (3) The downstream elimination of gravel in distributary channels is caused by declining boundary shear stress as a result of water discharge partitioning among the bifurcating channels. (4) Over longer time scales, gravel is contained on the delta topset due to frequent and discrete seismic events that produce subsidence and accommodation, so that coarse sediment cannot be transported to the axis of the Baikal Rift basin. The distribution of sediment grain size in deltaic channels, as related to hydrodynamics and sediment transport, plays a critical role in influencing stratigraphy, because the sustained tectonism leads to high preservation potential of the delta topset sedimentary deposits. Therefore, the Selenga River Delta provides an opportunity to explore the interactions between modern deltaic sedimentation processes and tectonics that affect the production of basin stratigraphy. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.