Late Miocene Extensional Deformation in the Sierra Bacha, Coastal Sonora, Mexico: Implications for the Kinematic Evolution of the Proto-Gulf of California

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dc.contributor.author Darin, Michael Harrison
dc.date.accessioned 2012-04-20T23:14:33Z
dc.date.available 2012-04-20T23:14:33Z
dc.date.issued 2011-12
dc.identifier.uri http://hdl.handle.net/1794/12189
dc.description xv, 95 p. : ill. (some col.), maps (some col.) Plate 1. Geologic Map of the Sierra Bacha, Coastal Sonora, Mexico (1:30,000 scale) attached as a separate file. en_US
dc.description.abstract The Gulf of California is an active rift basin formed by late Cenozoic dextral-oblique extension along the Pacific-North America plate boundary. Well exposed volcanic and sedimentary rocks in the Sierra Bacha, coastal Sonora, Mexico, preserve a history of proto-Gulf (late Miocene) deformation and offer insight into the structures and kinematics responsible for localization of the plate boundary and inception of the Gulf at about 6 Ma. Geologic mapping, fault kinematic analysis, and paleomagnetic data suggest that proto-Gulf deformation in the Sierra Bacha occurred primarily by ENE-WSW extension and that vertical-axis rotation related to dextral strain was minor. Lack of significant dextral shear supports an emerging model for proto-Gulf deformation in which dextral strain was not ubiquitous across Sonora but instead became localized during latest Miocene time in a narrow coastal shear zone that mechanically weakened the lithosphere and helped facilitate continental rupture. This thesis includes the "Geologic Map of the Sierra Bacha, Coastal Sonora, Mexico" as supplemental material. en_US
dc.description.sponsorship Committee in charge: Dr. Rebecca J. Dorsey, Chairperson; Dr. Marli B. Miller, Member; Dr. Ray J. Weldon II, Member en_US
dc.language.iso en_US en_US
dc.publisher University of Oregon en_US
dc.relation.ispartofseries University of Oregon theses, Dept. of Geological Sciences, M.S., 2011;
dc.rights rights_reserved en_US
dc.subject Geology en_US
dc.subject Continental Dynamics en_US
dc.subject Plate Tectonics en_US
dc.subject Earth sciences en_US
dc.subject Extension en_US
dc.subject Gulf of California en_US
dc.subject Sonora en_US
dc.subject Strain localization en_US
dc.subject Transtension en_US
dc.title Late Miocene Extensional Deformation in the Sierra Bacha, Coastal Sonora, Mexico: Implications for the Kinematic Evolution of the Proto-Gulf of California en_US
dc.title.alternative Implications for the Kinematic Evolution of the Proto-Gulf of California en_US
dc.type Thesis en_US


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