Chronology and rates of faulting of Ventura River terraces, California

Research Article| December 01, 1984 Chronology and rates of faulting of Ventura River terraces, California T. K. ROCKWELL; T. K. ROCKWELL 1Department of Geological Sciences, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar E. A. KELLER; E. A. KELLER 1Department of Geological Sciences, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar M. N. CLARK; M. N. CLARK 1Department of Geological Sciences, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar D. L. JOHNSON D. L. JOHNSON 2Department of Geography, University of Illinois, Urbana, Illinois 61801 Search for other works by this author on: GSW Google Scholar Author and Article Information T. K. ROCKWELL 1Department of Geological Sciences, University of California, Santa Barbara, California 93106 E. A. KELLER 1Department of Geological Sciences, University of California, Santa Barbara, California 93106 M. N. CLARK 1Department of Geological Sciences, University of California, Santa Barbara, California 93106 D. L. JOHNSON 2Department of Geography, University of Illinois, Urbana, Illinois 61801 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1984) 95 (12): 1466–1474. https://doi.org/10.1130/0016-7606(1984)95<1466:CAROFO>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 Email Permissions Search Site Citation T. K. ROCKWELL, E. A. KELLER, M. N. CLARK, D. L. JOHNSON; Chronology and rates of faulting of Ventura River terraces, California. GSA Bulletin 1984;; 95 (12): 1466–1474. doi: https://doi.org/10.1130/0016-7606(1984)95<1466:CAROFO>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 New evidence concerning the chronology of four late Pleistocene terraces of the Ventura River near Oak View, California, that are vertically offset and tilted by reverse and reverse flexural-slip faults provides a means of estimating rates of fault movement and downcutting by the Ventura River. Radiocarbon ages of charcoal contained within terrace deposits date two of the terraces. Correlation of soils that have developed on terrace deposits and extrapolation of the rate of vertical displacement of the Arroyo Parida-Santa Ana fault (not a flexural-slip fault) date the others. Resulting age estimates for the four main late Pleistocene terraces are Qt5b = 30,000 Qt6a = 38,000, Qt6b = 54,000, and Qt6c = 92,000 yr B.P.Vertical-slip rates on flexural-slip faults range from <0.3 to 1.1 mm/yr and apparently are related to the rate, form, and mechanics of folding of the north limb of the Ayers Creek–Canada Larga syncline.Average rates of downcutting of the Ventura River for several intervals during the late Pleistocene, estimated from the chronology and relative elevation of river terraces north of the Arroyo Panda–Santa Ana fault upstream from the zone of faulting, vary from ∼0.5 to 1.3 mm/yr. The range in rates probably reflects variations in local uplift as well as adjustments to changing eustatic sea level, climatic conditions, and/or regional deformation of the western Transverse Ranges.The average rate of downcutting of the Ventura River north of the zone of flexural-slip faulting is ∼0.8 mm/yr, compared with 1.2 to 2.2 mm/yr in the deformation zone immediately to the south. This apparently indicates that during tectonic deformation there is an approximate balance between the rate of uplift due to faulting and folding and the rate of downcutting by the fluvial system. 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.