Research Article| April 01, 1986 Paleohydrology of pool-and-riffle pattern development: Boulder Creek, Utah JIM E. O'CONNOR; JIM E. O'CONNOR 1Department of Geosciences, The University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar ROBERT H. WEBB; ROBERT H. WEBB 1Department of Geosciences, The University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar VICTOR R. BAKER VICTOR R. BAKER 1Department of Geosciences, The University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar Author and Article Information JIM E. O'CONNOR 1Department of Geosciences, The University of Arizona, Tucson, Arizona 85721 ROBERT H. WEBB 1Department of Geosciences, The University of Arizona, Tucson, Arizona 85721 VICTOR R. BAKER 1Department of Geosciences, The University of Arizona, Tucson, Arizona 85721 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1986) 97 (4): 410–420. https://doi.org/10.1130/0016-7606(1986)97<410:POPPDB>2.0.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 JIM E. O'CONNOR, ROBERT H. WEBB, VICTOR R. BAKER; Paleohydrology of pool-and-riffle pattern development: Boulder Creek, Utah. GSA Bulletin 1986;; 97 (4): 410–420. doi: https://doi.org/10.1130/0016-7606(1986)97<410:POPPDB>2.0.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 low-flow channel morphology of Boulder Creek is characterized by a well-developed pool-and-riffle pattern. The riffles consist of accumulations of basaltic boulders deposited from upstream source areas during extremely large flows. Paleoflood water-surface profiles defined by high-water indicators such as slack-water sediments and silt lines indicate that discharges of up to 400±50 m3/s have affected the lower reaches of this bedrock stream system. Stratigraphic relationships and archaeologic and radiometric age constraints indicate that at least four large-magnitude, low-frequency flow events have occurred within the past 500 to 1,000 radiocarbon years B.P.Step-backwater hydraulic reconstructions of these large flows suggest that the positions of the boulder-comprised riffles are controlled by spatial variations in large-flow stream power. Boulder deposition occurs where channel stream power drops below critical-power thresholds necessary for boulder transport. High-discharge stream-power minima occur in reaches immediately upstream of canyon bends and constrictions and downstream of canyon expansions. The low-flow riffles occur at these sites. Comparison of calculated stream-power values and measured boulder sizes with established coarse-particle transport relationships indicates that a 400-m3/s flow is approximately the minimum discharge competent to affect this pool-and-riffle pattern. 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.