QUANTITATIVE TECTONIC GEOMORPHOLOGY WITH APPLICATIONS TO NEOTECTONICS OF NORTHWESTERN ARIZONA

Persistent Link:
http://hdl.handle.net/10150/187532
Title:
QUANTITATIVE TECTONIC GEOMORPHOLOGY WITH APPLICATIONS TO NEOTECTONICS OF NORTHWESTERN ARIZONA
Author:
Mayer, Larry
Issue Date:
1982
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:
Quantitative tectonic geomorphology is based on a conceptual synthesis between historical and process geomorphology that integrates physical models of geodynamics and erosional kinematics. Geodynamic models of flexure, heat flow and isostasy provide a framework for regional investigation. Topographic analysis and related filtering techniques allow for the description or delineation of regional features. Erosional kinematics modeled by a diffusion equation of heat flow allow the quantitative dating of uplifts across known structures. For large uplifts, the geometry of streams crossing faults is the key element in analyzing age. Theoretically, these faulted stream channels will readjust their gradients with time and these changes can be described as a diffusion process. At this time, however, sufficient data are not available to rigorously constrain estimates of uplift age. For small uplifts, those that result in piedmont fault scarps, statistical analysis of hundreds of scarp profiles suggests that the age of the faulting can be constrained. The apparent morphologic age of fault scarps is strongly affected by variables such as the resistance to erosion of the faulted rock type, but for scarps in alluvium, morphologic dating methods appear to be robust. Quantitative tectonic geomorphology of northwest Arizona and environs suggests that regional topographic patterns can be explained by nonuniform extension of the lithosphere. This process probably began as sub lithospheric erosion about 35 m.y. ago and resulted from a prolonged period of plate convergence and subduction. Superimposed on this predominantly thermal event was younger Basin and Range crustal extension and the opening of the Gulf of California. The Grand Wash fault, the boundary between the Basin and Range and Colorado Plateau physiographic provinces, has been active, though in decreasing amounts, from late Miocene to late Pleistocene time. Morphology of Quaternary piedmont fault scarps that exhibit repeated faulting suggest recurrence intervals on the order of 50,000-100,000 years. The Pitaycachi fault in Sonora, Mexico, which has similar recurrence intervals, broke in 1877, suggesting perhaps that many of the late Pleistocene faults in northwestern Arizona and environs are also due to break.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Bull, William B.
Committee Chair:
Bull, William B.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleQUANTITATIVE TECTONIC GEOMORPHOLOGY WITH APPLICATIONS TO NEOTECTONICS OF NORTHWESTERN ARIZONAen_US
dc.creatorMayer, Larryen_US
dc.contributor.authorMayer, Larryen_US
dc.date.issued1982en_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.abstractQuantitative tectonic geomorphology is based on a conceptual synthesis between historical and process geomorphology that integrates physical models of geodynamics and erosional kinematics. Geodynamic models of flexure, heat flow and isostasy provide a framework for regional investigation. Topographic analysis and related filtering techniques allow for the description or delineation of regional features. Erosional kinematics modeled by a diffusion equation of heat flow allow the quantitative dating of uplifts across known structures. For large uplifts, the geometry of streams crossing faults is the key element in analyzing age. Theoretically, these faulted stream channels will readjust their gradients with time and these changes can be described as a diffusion process. At this time, however, sufficient data are not available to rigorously constrain estimates of uplift age. For small uplifts, those that result in piedmont fault scarps, statistical analysis of hundreds of scarp profiles suggests that the age of the faulting can be constrained. The apparent morphologic age of fault scarps is strongly affected by variables such as the resistance to erosion of the faulted rock type, but for scarps in alluvium, morphologic dating methods appear to be robust. Quantitative tectonic geomorphology of northwest Arizona and environs suggests that regional topographic patterns can be explained by nonuniform extension of the lithosphere. This process probably began as sub lithospheric erosion about 35 m.y. ago and resulted from a prolonged period of plate convergence and subduction. Superimposed on this predominantly thermal event was younger Basin and Range crustal extension and the opening of the Gulf of California. The Grand Wash fault, the boundary between the Basin and Range and Colorado Plateau physiographic provinces, has been active, though in decreasing amounts, from late Miocene to late Pleistocene time. Morphology of Quaternary piedmont fault scarps that exhibit repeated faulting suggest recurrence intervals on the order of 50,000-100,000 years. The Pitaycachi fault in Sonora, Mexico, which has similar recurrence intervals, broke in 1877, suggesting perhaps that many of the late Pleistocene faults in northwestern Arizona and environs are also due to break.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_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.advisorBull, William B.en_US
dc.contributor.chairBull, William B.en_US
dc.contributor.committeememberDickinson, W. R.en_US
dc.contributor.committeememberFlessa, K.en_US
dc.contributor.committeememberMcCullough, E. J.en_US
dc.contributor.committeememberSbar, M.en_US
dc.identifier.proquest8303399en_US
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