Investigating the Coupling Between Tectonics, Climate and Sedimentary Basin Development

Persistent Link:
http://hdl.handle.net/10150/217092
Title:
Investigating the Coupling Between Tectonics, Climate and Sedimentary Basin Development
Author:
Engelder, Todd
Issue Date:
2012
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:
Sedimentary deposits have been broadly used to constrain past climate change and tectonic histories within mountain belts. This dissertation summarizes three studies that evaluate the effects of climate change and tectonics on sedimentary basin development. (1) The paleoslope estimation method, a method for calculating the threshold slope of a fluvial deposit, does not account for the stochastic variations in water depth in alluvial channels caused by climatic and autogenic processes. Therefore, we test the robustness of applying the paleoslope estimation method in a tectonic context. Based on our numerical modeling results, we conclude that if given sufficient time gravel can prograde long distances at regional slopes less than the minimum transport slope calculated with the paleoslope estimation method if water depth varies stochastically in time, and thus, caution should be exercised when evaluating regional slopes measured from the rock record in a tectonic context. (2) The role of crustal thickening, lithospheric removal, and climate change in driving surface uplift in the central Andes in southern Bolivia and changes in the creation of accommodation space and depositional facies in the adjacent foreland basin has been a topic of debate over the last decade. Our numerical modeling results show that gradual rise of the Eastern Cordillera above 2-3 km prior to 22 Ma leads to sufficient sediment accommodation for the Oligocene-Miocene foreland basin stratigraphy, and thus, the Eastern Cordillera gained the majority of its modern elevation prior to 10 Ma. Also, we conclude that major changes in grain size and depositional rates are primarily controlled by mountain-belt migration (i.e., climate change and lithospheric removal are secondary mechanisms). (3) Existing equations for predicting the long-term bedload sediment flux in alluvial channels include mean discharge as a controlling variable but do not explicitly include variations in discharge through time. We develop an analytic equation for the long-term bedload sediment flux that incorporates both the mean and coefficient of variation of discharge. Our results show that although increasing aridity leads to an increase in large discharges with respect to small discharges, long-term bedload sediment transport rates decrease for both gravel and sand-bed rivers with increasing aridity.
Type:
text; Electronic Dissertation
Keywords:
diffusion; foreland basin; sediment transport; stochastic processes; Geosciences; central Andes; climate impacts
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Geosciences
Degree Grantor:
University of Arizona
Advisor:
Pelletier, Jon D.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleInvestigating the Coupling Between Tectonics, Climate and Sedimentary Basin Developmenten_US
dc.creatorEngelder, Todden_US
dc.contributor.authorEngelder, Todden_US
dc.date.issued2012-
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.abstractSedimentary deposits have been broadly used to constrain past climate change and tectonic histories within mountain belts. This dissertation summarizes three studies that evaluate the effects of climate change and tectonics on sedimentary basin development. (1) The paleoslope estimation method, a method for calculating the threshold slope of a fluvial deposit, does not account for the stochastic variations in water depth in alluvial channels caused by climatic and autogenic processes. Therefore, we test the robustness of applying the paleoslope estimation method in a tectonic context. Based on our numerical modeling results, we conclude that if given sufficient time gravel can prograde long distances at regional slopes less than the minimum transport slope calculated with the paleoslope estimation method if water depth varies stochastically in time, and thus, caution should be exercised when evaluating regional slopes measured from the rock record in a tectonic context. (2) The role of crustal thickening, lithospheric removal, and climate change in driving surface uplift in the central Andes in southern Bolivia and changes in the creation of accommodation space and depositional facies in the adjacent foreland basin has been a topic of debate over the last decade. Our numerical modeling results show that gradual rise of the Eastern Cordillera above 2-3 km prior to 22 Ma leads to sufficient sediment accommodation for the Oligocene-Miocene foreland basin stratigraphy, and thus, the Eastern Cordillera gained the majority of its modern elevation prior to 10 Ma. Also, we conclude that major changes in grain size and depositional rates are primarily controlled by mountain-belt migration (i.e., climate change and lithospheric removal are secondary mechanisms). (3) Existing equations for predicting the long-term bedload sediment flux in alluvial channels include mean discharge as a controlling variable but do not explicitly include variations in discharge through time. We develop an analytic equation for the long-term bedload sediment flux that incorporates both the mean and coefficient of variation of discharge. Our results show that although increasing aridity leads to an increase in large discharges with respect to small discharges, long-term bedload sediment transport rates decrease for both gravel and sand-bed rivers with increasing aridity.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectdiffusionen_US
dc.subjectforeland basinen_US
dc.subjectsediment transporten_US
dc.subjectstochastic processesen_US
dc.subjectGeosciencesen_US
dc.subjectcentral Andesen_US
dc.subjectclimate impactsen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineGeosciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorPelletier, Jon D.en_US
dc.contributor.committeememberDeCelles, Peteren_US
dc.contributor.committeememberKapp, Paulen_US
dc.contributor.committeememberChase, Clementen_US
dc.contributor.committeememberReiners, Peteren_US
dc.contributor.committeememberPelletier, Jon D.en_US
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