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dc.contributor.authorten Brink, Uri S.  Concept link
dc.contributor.authorZhang, Jie  Concept link
dc.contributor.authorBrocher, Thomas M.  Concept link
dc.contributor.authorOkaya, David A.  Concept link
dc.contributor.authorKlitgord, Kim D.  Concept link
dc.contributor.authorFuis, Gary S.  Concept link
dc.date.accessioned2018-11-07T16:07:55Z
dc.date.available2018-11-07T16:07:55Z
dc.date.issued2000-03-10
dc.identifier.citationJournal of Geophysical Research: Solid Earth 105 (2000): 5835-5857en_US
dc.identifier.urihttps://hdl.handle.net/1912/10688
dc.descriptionAuthor Posting. © American Geophysical Union, 2000. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 105 (2000): 5835-5857, doi:10.1029/1999JB900318.en_US
dc.description.abstractWe use new seismic and gravity data collected during the 1994 Los Angeles Region Seismic Experiment (LARSE) to discuss the origin of the California Inner Continental Borderland (ICB) as an extended terrain possibly in a metamorphic core complex mode. The data provide detailed crustal structure of the Borderland and its transition to mainland southern California. Using tomographic inversion as well as traditional forward ray tracing to model the wide-angle seismic data, we find little or no sediments, low (#6.6 km/s) P wave velocity extending down to the crust-mantle boundary, and a thin crust (19 to 23 km thick). Coincident multichannel seismic reflection data show a reflective lower crust under Catalina Ridge. Contrary to other parts of coastal California, we do not find evidence for an underplated fossil oceanic layer at the base of the crust. Coincident gravity data suggest an abrupt increase in crustal thickness under the shelf edge, which represents the transition to the western Transverse Ranges. On the shelf the Palos Verdes Fault merges downward into a landward dipping surface which separates “basement” from low-velocity sediments, but interpretation of this surface as a detachment fault is inconclusive. The seismic velocity structure is interpreted to represent Catalina Schist rocks extending from top to bottom of the crust. This interpretation is compatible with a model for the origin of the ICB as an autochthonous formerly hot highly extended region that was filled with the exhumed metamorphic rocks. The basin and ridge topography and the protracted volcanism probably represent continued extension as a wide rift until ;13 m.y. ago. Subduction of the young and hot Monterey and Arguello microplates under the Continental Borderland, followed by rotation and translation of the western Transverse Ranges, may have provided the necessary thermomechanical conditions for this extension and crustal inflow.en_US
dc.description.sponsorshipThe LARSE experiment was funded by NSF EAR-9416774, the U.S. Geological Survey’s Earthquake Hazards and Coastal and Marine Programs, and by the Southern California Earthquake Center (SCEC).en_US
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/1999JB900318
dc.titleGeophysical evidence for the evolution of the California Inner Continental Borderland as a metamorphic core complexen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/1999JB900318


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