The Cretaceous - Tertiary Tectonic Evolution of the Lhasa terrane, Tibet

Persistent Link:
http://hdl.handle.net/10150/195070
Title:
The Cretaceous - Tertiary Tectonic Evolution of the Lhasa terrane, Tibet
Author:
Volkmer, John E.
Issue Date:
2010
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:
A thorough understanding of Tibetan Plateau growth requires knowledge of the geological evolution of the Tibetan terranes as they were accreted to the Eurasian margin during the Phanerozoic. This dissertation research addresses the tectonic evolution of the southernmost of these, the Lhasa terrane of Tibet from the Late Jurassic to Eocene. The data and insights presented herein are the result of extensive geologic fieldwork in the northern and central Lhasa terrane of Tibet. In this work I present new geologic mapping and thermochronologic data that reveals a terrane scale passive roof thrust belt in the northern Lhasa terrane that accommodates significant upper crustal shortening without exhuming basement rocks. Through the development of a geospatially referenced database of igneous crystallization ages, I show that Cretaceous magmatism on the Lhasa terrane was not static, but exhibited significant temporal-spatial migrations. I interpret these movements as the result of variations in Neo-Tethyan slab dip and suggest that these variations are a major factor in shaping the Cretaceous tectonics of the Lhasa terrane. Finally, I present the Cretaceous-Eocene tectonic evolution of the Lhasa terrane that shows that the Lhasa terrane was above sea level and likely had attained significant elevation prior to the accretion of India to Eurasia and that the development of the high elevation Plateau developed outward from a central core, rather than from south to north as is commonly thought. These insights refute the widely held view that the Tibetan Plateau is the result of the Cenozoic Indo-Asian collision.
Type:
text; Electronic Dissertation
Keywords:
magmatism; passive-roof thrust; tectonics; Tibet
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Kapp, Paul

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleThe Cretaceous - Tertiary Tectonic Evolution of the Lhasa terrane, Tibeten_US
dc.creatorVolkmer, John E.en_US
dc.contributor.authorVolkmer, John E.en_US
dc.date.issued2010en_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.abstractA thorough understanding of Tibetan Plateau growth requires knowledge of the geological evolution of the Tibetan terranes as they were accreted to the Eurasian margin during the Phanerozoic. This dissertation research addresses the tectonic evolution of the southernmost of these, the Lhasa terrane of Tibet from the Late Jurassic to Eocene. The data and insights presented herein are the result of extensive geologic fieldwork in the northern and central Lhasa terrane of Tibet. In this work I present new geologic mapping and thermochronologic data that reveals a terrane scale passive roof thrust belt in the northern Lhasa terrane that accommodates significant upper crustal shortening without exhuming basement rocks. Through the development of a geospatially referenced database of igneous crystallization ages, I show that Cretaceous magmatism on the Lhasa terrane was not static, but exhibited significant temporal-spatial migrations. I interpret these movements as the result of variations in Neo-Tethyan slab dip and suggest that these variations are a major factor in shaping the Cretaceous tectonics of the Lhasa terrane. Finally, I present the Cretaceous-Eocene tectonic evolution of the Lhasa terrane that shows that the Lhasa terrane was above sea level and likely had attained significant elevation prior to the accretion of India to Eurasia and that the development of the high elevation Plateau developed outward from a central core, rather than from south to north as is commonly thought. These insights refute the widely held view that the Tibetan Plateau is the result of the Cenozoic Indo-Asian collision.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectmagmatismen_US
dc.subjectpassive-roof thrusten_US
dc.subjecttectonicsen_US
dc.subjectTibeten_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.chairKapp, Paulen_US
dc.contributor.committeememberDeCelles, Peteren_US
dc.contributor.committeememberGehrels, Georgeen_US
dc.contributor.committeememberReiners, Peteren_US
dc.contributor.committeememberQuade, Jayen_US
dc.identifier.proquest10959en_US
dc.identifier.oclc659754883en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.