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dc.contributor.authorDupuis, Carol A.
dc.date.accessioned2022-11-01T16:14:59Z
dc.date.available2022-11-01T16:14:59Z
dc.date.issued1997-05-31
dc.identifier.urihttp://hdl.handle.net/1808/33646
dc.descriptionM.S. University of Kansas, Geology 1997en_US
dc.description.abstractThe Arica Mountains lie along the northern edge of the Maria fold and thrust belt and along the western boundary of the Colorado River extensional corridor. The range lies within the hanging wall of the regional detachment fault system. Rocks within the AricaMountains consist of metamorpho.sed Paleozoic cratonal and Mesozoic metasedimentary rocks that have been ductilely deformed and juxtaposed against a Precambrian gneissic complex. Unfoliated Cretaceous granodiorite intrudes the Precambrian assemblage. Large-scale, isoclinal folds deform the Paleozoic and Mesozoic metasedimentary rocks and are refolded by a second system. These refolded folds are cut by the Priest Mine shear zone, a high-angle sinistral shear zone, that omits strata. These previously formed structures are truncated by the Arica shear zone a moderately-dipping normal-sense ductile shear zone. A felsite dike crosscuts the Arica shear zone and yields a U-Pb (zircon) age of 108 - 114 Ma.

A northeast dipping low-angle normal fault of presumed Tertiary age displaces hanging-wall rocks >800 meters to the east-southeast. Brittle faults bound the range to the west, south and east. The Arica Mountains have been tilted a minimum of 30° to the west, and prior to Tertiary extension, the range resided in a position close to the northern end of the Little Maria Mountains. Tertiary sediments in depositional contact with pre-Tertiary basement rocks within the Arica Mountains indicate that the range was at shallow-crustal levels at the onset of Tertiary extension.

Synextensional basin deposits within the hanging wall of the Colorado River extensional corridor have been divided into six structural domains. A new domain, the Rice domain, is proposed based on correlations of Tertiary deposits within the Arica and Riverside mountains. Based on varying dips within synextensional basin deposits, fault blocks within the Rice domain were first tilted between 23 and 20 Ma. This was followed by a second episode of tilting which occurred between 20 and 18 Ma. The presence of megabreccia deposits along the western trace of the breakaway zone suggest that movement along this segment of the zone began near its present position during the early Miocene.
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dc.publisherUniversity of Kansasen_US
dc.rightsThis item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.en_US
dc.titleThe Mesozoic and Tertiary deformational history of the Arica Mountains, southeastern Californiaen_US
dc.typeThesisen_US
dc.thesis.degreeDisciplineGeology
dc.thesis.degreeLevelM.S.
kusw.bibid1733000
dc.rights.accessrightsopenAccessen_US


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