Bedrock benches and boulder bars: Floods in the Burdekin Gorge of Australia

Research Article| June 01, 1992 Bedrock benches and boulder bars: Floods in the Burdekin Gorge of Australia ELLEN E. WOHL ELLEN E. WOHL 1Department of Earth Resources, Colorado State University, Fort Collins, Colorado 80523 Search for other works by this author on: GSW Google Scholar Author and Article Information ELLEN E. WOHL 1Department of Earth Resources, Colorado State University, Fort Collins, Colorado 80523 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1992) 104 (6): 770–778. https://doi.org/10.1130/0016-7606(1992)1042.3.CO;2 Article history First Online: 01 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 ELLEN E. WOHL; Bedrock benches and boulder bars: Floods in the Burdekin Gorge of Australia. GSA Bulletin 1992;; 104 (6): 770–778. doi: https://doi.org/10.1130/0016-7606(1992)1042.3.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 SocietyGSA Bulletin Search Advanced Search Abstract The Burdekin Gorge of northeastern Australia lies within the seasonal tropics and is characterized by high discharge variability. Slackwater sediments and paleostage indicators in the gorge record seven large floods that have occurred during the past 1,200 yrs. These floods range in magnitude from 11,000 to 30,000 m3s-1 and are characterized by large downstream variations in hydraulics. The floods generate high values of velocity, boundary shear stress, and stream power per unit area. Downstream fluctuations in these variables help to explain the location of boulder bars, high flood levees, small-scale erosional features in the bedrock, and the formation of inner channels. Boulder bars and flood levees form where shear stress and stream power decrease due to channel widening. Small-scale erosional features, such as potholes and troughs, are best developed at sites of channel constriction and associated increases in shear stress and stream power. The development of the inner channel appears to be controlled by complex interactions between bedrock lithology and structure, and by flow hydraulics. All of the channel features are related to the hydraulics of large floods, which therefore are the dominant controls on many aspects of channel morphology in this bedrock gorge. 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.