Research Article| June 01, 1998 Upper crustal structure and Neogene tectonic development of the California continental borderland Robert G. Bohannon; Robert G. Bohannon 1U.S. Geological Survey, M.S. 999, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Eric Geist Eric Geist 1U.S. Geological Survey, M.S. 999, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1998) 110 (6): 779–800. https://doi.org/10.1130/0016-7606(1998)110<0779:UCSANT>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 Robert G. Bohannon, Eric Geist; Upper crustal structure and Neogene tectonic development of the California continental borderland. GSA Bulletin 1998;; 110 (6): 779–800. doi: https://doi.org/10.1130/0016-7606(1998)110<0779:UCSANT>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 Multichannel seismic-reflection data, sonobuoy seismic-refraction data, and regional geology are used to define the upper crustal structure of the southern California continental borderland and to delineate the characteristics of the main lithotectonic belts of the region. The Catalina Schist belt is separated on its west side from the gently deformed Nicolas forearc belt by faults that have steep west dips and pronounced normal separations. On its east side the schist belt is bounded by a large detachment fault that dips gently to the east beneath the west edge of the Peninsular Ranges belt at the coastline near Oceanside. The Catalina Schist was uplifted from middle crustal depths and exposed during a major event of extensional tectonism that started in early Miocene time in conjunction with about 10° of clockwise rotation of the western Transverse Ranges belt. Part of the uplift of the Catalina Schist could have occurred on the detachment fault, but it is thought to have mostly occurred on the steep faults that bound the west edge of the schist belt. A large amount of uplift is required, and it probably involved strong footwall flexural deformation in the wake of the translating and rotating western Transverse Ranges and Nicolas forearc belts. Extension, accompanied by probable large amounts of right slip, continued in the borderland region during and after middle Miocene time. The later stage of extension was accompanied by rapid clockwise rotation of the western Transverse Ranges of at least 90°. Most of the borderland, including the belt of schist that was uplifted in early Miocene time, was further deformed into numerous basins and ridges during this stage of oblique extension. The primary driving force for the deformation is thought to have been derived from the rapid northwest motion of the Pacific plate after it had become coupled to the Farallon plate system, which had previously been subducted beneath the borderland. 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.
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Bohannon et al. (1998) studied this question.