Neotectonics of the San Cayetano fault, Transverse Ranges, California

Research Article| April 01, 1988 Neotectonics of the San Cayetano fault, Transverse Ranges, California THOMAS ROCKWELL THOMAS ROCKWELL 1Department of Geological Sciences, San Diego State University, San Diego, California 92182 Search for other works by this author on: GSW Google Scholar Author and Article Information THOMAS ROCKWELL 1Department of Geological Sciences, San Diego State University, San Diego, California 92182 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1988) 100 (4): 500–513. https://doi.org/10.1130/0016-7606(1988)100<0500:NOTSCF>2.3.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 THOMAS ROCKWELL; Neotectonics of the San Cayetano fault, Transverse Ranges, California. GSA Bulletin 1988;; 100 (4): 500–513. doi: https://doi.org/10.1130/0016-7606(1988)100<0500:NOTSCF>2.3.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 Study of late Quaternary alluvial deposits cut by the San Cayetano reverse fault indicates that the dip-slip rate of faulting increases from 1.05 ± 0.2 mm/yr at Sisar Creek near the western end of the fault eastward to 1.35 ± 0.4 mm/ yr at Bear Canyon and 2.35 ± 0.55 to 4.15 ± 0.85 mm/yr at Mud Creek. At Timber Canyon near the central part of the fault, a minimum slip rate of 3.6 ± 0.4 mm/yr is suggested by fanhead segmentation; however, a higher slip rate of 8.75 ± 1.95 mm/yr is suggested by stratigraphic evidence. Stratigraphic separation of 7.5 km in less than 1 m.y. across the fault between Fillmore and Piru indicates a slip rate of at least 7.5 mm/yr for the eastern section of the fault. Recent activity is shown by faulted Holocene or latest Pleistocene fan alluvium and colluvium at Bear Canyon and the Silverthread oil field, respectively, and inferred at Timber Canyon by fanhead deposition.Active folding of the footwall is demonstrated by tilted and faulted Holocene and Pleistocene alluvial fans: present tilt rates approach 1°/10 ka yr, and associated bedding plane faulting rates are about 0.5 to 1.5 mm/yr. The hanging wall, however, does not appear to be involved in active deformation, inasmuch as Pleistocene deposits as old as several hundred thousand years are not tilted or affected by bedding-plane faulting. The only exception is in the Silverthread field area, where hanging-wall deformation is directly relatable to fault geometry, not folding of the hanging-wall rocks.The lack of documented moderate- to large-magnitude historical earthquakes on this fault is in strong contrast with its demonstrated late Quaternary activity. Based on its length, slip rate, overall geometry, and segmentation into two parts, a recurrence interval of between 200 and 600 yr for the western segment and about 230 yr for the eastern segment is suggested. 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.