INVESTIGATION OF CENOZOIC CRUSTAL EXTENSION INFERRED FROM SEISMIC REFLECTION PROFILES AND FIELD RELATIONS, SE ARIZONA

Persistent Link:
http://hdl.handle.net/10150/195881
Title:
INVESTIGATION OF CENOZOIC CRUSTAL EXTENSION INFERRED FROM SEISMIC REFLECTION PROFILES AND FIELD RELATIONS, SE ARIZONA
Author:
Arca, Mehmet Serkan
Issue Date:
2009
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Mid-Tertiary metamorphic core complexes in the Basin and Range province of the western North American Cordillera are characterized by large-magnitude extensional deformation. Numerous models have been proposed for the kinematic evolution of these metamorphic core complexes. Such models generally invoke footwall isotatic rebound due to tectonic denudation, and the presence of a weak middle crust capable of flow at mid-crustal levels. In popular models of Cordilleran-style metamorphic core-complex development, initial extension occurs along a breakaway fault, which subsequently is deformed into a synform and abandoned in response to isostatic rebound, with new faults breaking forward in the dominant transport direction. In southeast Arizona, the Catalina and Pinaleño Mountains core complexes have been pointed to as type examples of this model. In this study, the “traditional” core-complex model is tested through analysis of field relations and geochronological age constraints, and by interpretation of seismic reflection profiles along a transect incorporating these core complexes. Elements of these linked core-complex systems, from southwest to northeast, include the Tucson Basin, the Santa Catalina-Rincon Mountains, the San Pedro trough, the Galiuro Mountains, the Sulphur Springs Valley, the Pinaleño Mountains, and the Safford Basin. A new digital compilation of geological data, across highly extended terranes, in conjunction with reprocessing and interpretation of a suite of industry 2-D seismic reflection profiles spanning nearly sub-parallel to regional extension, illuminate subsurface structural features related to Cenozoic crustal extension and provide new constraints on evolution of core complexes in southeast Arizona. The main objective is to develop a new kinematic model for mid-Tertiary extension and core complex evolution in southeast Arizona that incorporates new geological and geophysical observations. Geological and seismological data indicate that viable alternative models explain observations at least as well as previous core-complex models. In contrast to the “traditional” model often employed for these structures, our models suggest that the southwest- and northeast-dipping normal-fault systems on the flanks of the Galiuro Mountains extend to mid-crustal depths beneath the San Pedro trough and Sulphur-Springs Valley, respectively. In our interpretations and models, these oppositely vergent fault systems are not the breakaway faults for the Catalina and Pinaleño detachment systems.
Type:
text; Electronic Dissertation
Keywords:
"Traditional" core-complex evolutionary models; Alternative core-complex kinematic models; Breakaway zone; Crustal extension; Low-angle (detachment) faulting; Metamorphic core complexes
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Johnson, Roy A.
Committee Chair:
Johnson, Roy A.

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleINVESTIGATION OF CENOZOIC CRUSTAL EXTENSION INFERRED FROM SEISMIC REFLECTION PROFILES AND FIELD RELATIONS, SE ARIZONAen_US
dc.creatorArca, Mehmet Serkanen_US
dc.contributor.authorArca, Mehmet Serkanen_US
dc.date.issued2009en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractMid-Tertiary metamorphic core complexes in the Basin and Range province of the western North American Cordillera are characterized by large-magnitude extensional deformation. Numerous models have been proposed for the kinematic evolution of these metamorphic core complexes. Such models generally invoke footwall isotatic rebound due to tectonic denudation, and the presence of a weak middle crust capable of flow at mid-crustal levels. In popular models of Cordilleran-style metamorphic core-complex development, initial extension occurs along a breakaway fault, which subsequently is deformed into a synform and abandoned in response to isostatic rebound, with new faults breaking forward in the dominant transport direction. In southeast Arizona, the Catalina and Pinaleño Mountains core complexes have been pointed to as type examples of this model. In this study, the “traditional” core-complex model is tested through analysis of field relations and geochronological age constraints, and by interpretation of seismic reflection profiles along a transect incorporating these core complexes. Elements of these linked core-complex systems, from southwest to northeast, include the Tucson Basin, the Santa Catalina-Rincon Mountains, the San Pedro trough, the Galiuro Mountains, the Sulphur Springs Valley, the Pinaleño Mountains, and the Safford Basin. A new digital compilation of geological data, across highly extended terranes, in conjunction with reprocessing and interpretation of a suite of industry 2-D seismic reflection profiles spanning nearly sub-parallel to regional extension, illuminate subsurface structural features related to Cenozoic crustal extension and provide new constraints on evolution of core complexes in southeast Arizona. The main objective is to develop a new kinematic model for mid-Tertiary extension and core complex evolution in southeast Arizona that incorporates new geological and geophysical observations. Geological and seismological data indicate that viable alternative models explain observations at least as well as previous core-complex models. In contrast to the “traditional” model often employed for these structures, our models suggest that the southwest- and northeast-dipping normal-fault systems on the flanks of the Galiuro Mountains extend to mid-crustal depths beneath the San Pedro trough and Sulphur-Springs Valley, respectively. In our interpretations and models, these oppositely vergent fault systems are not the breakaway faults for the Catalina and Pinaleño detachment systems.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subject"Traditional" core-complex evolutionary modelsen_US
dc.subjectAlternative core-complex kinematic modelsen_US
dc.subjectBreakaway zoneen_US
dc.subjectCrustal extensionen_US
dc.subjectLow-angle (detachment) faultingen_US
dc.subjectMetamorphic core complexesen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGeosciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorJohnson, Roy A.en_US
dc.contributor.chairJohnson, Roy A.en_US
dc.contributor.committeememberKapp, Paulen_US
dc.contributor.committeememberBeck, Susan L.en_US
dc.contributor.committeememberZandt, Georgeen_US
dc.contributor.committeememberBennett, Rick A.en_US
dc.identifier.proquest10664en_US
dc.identifier.oclc752260933en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.