Calculations of Flows Needed to Transport Coarse Fraction of Boulder Creek Alluvium at Boulder, Colorado

Abstract

Research Article| March 01, 1980 Calculations of Flows Needed to Transport Coarse Fraction of Boulder Creek Alluvium at Boulder, Colorado W. C. Bradley; W. C. Bradley 1Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309 Search for other works by this author on: GSW Google Scholar A. I. Mears A. I. Mears 2Natural Hazards Consultant, 222 East Gothic Avenue, Gunnison, Colorado 81230 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1980) 91 (3_Part_II): 1057–1090. https://doi.org/10.1130/GSAB-P2-91-1057 Article history received: 24 Jul 1979 rev-recd: 14 Sep 1979 accepted: 17 Sep 1979 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation W. C. Bradley, A. I. Mears; Calculations of Flows Needed to Transport Coarse Fraction of Boulder Creek Alluvium at Boulder, Colorado. GSA Bulletin 1980;; 91 (3_Part_II): 1057–1090. doi: https://doi.org/10.1130/GSAB-P2-91-1057 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 Near the western limit of Boulder, Colorado, stands the Justice Center, a large new building used jointly by city and county. Its base lies embedded in alluvium of the Boulder Creek flood plain. Excavation occurred at two different times: first in the late 1950s for a structure that was never completed, then again in 1975 for the present building. Remaining as a legacy of both digging efforts are boulders that were too large for crushing or removal (Fig. 1). We measured the 89 largest boulders whose three axes were visible (see appendix for axial dimensions and Corey shape factors). The coarsest 25% of this sample had a mean intermediate dimension of 188 cm (6.2 ft), a value we will use for grain size of the coarse alluvial fraction. The largest boulder had an intermediate diameter of 230 cm (7.7 ft).What kind of flows are needed to move 188-cm (6.2-ft) boulders? This study attempts to answer the question. It is a question of practical importance to communities such as Boulder which are concerned with the effects of exceptional floods. 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.