The Late Miocene through Modern Evolution of the Zhada Basin, South-Western Tibet

Persistent Link:
http://hdl.handle.net/10150/194652
Title:
The Late Miocene through Modern Evolution of the Zhada Basin, South-Western Tibet
Author:
Saylor, Joel Edward
Issue Date:
2008
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:
The uplift history of the Tibetan Plateau is poorly constrained in part due to its complex and extended tectonic history. This study uses basin analysis, stable isotope analysis, magnetostratigraphy, detrital zircon U-Pb dating, and paleoaltimetry, and frequency analysis to reconstruct the tectonic, spatial, and environmental evolution of the Zhada basin in southwestern Tibet since the late Miocene. The Zhada Formation, which occupies the Zhada basin and consists of ~ 850 m of fluvial, alluvial fan, eolian, and lacustrine sediments, is undeformed and lies in angular unconformity above Tethyan sedimentary sequence strata. The most negative Miocene δ¹⁸Opsw (paleo-surface water) values reconstructed from aquatic gastropods are significantly more negative than the most negative modern δ¹⁸O(sw) (surface water) values. In the absence of any known climate change which would have produced this difference, we interpret it as indicating a decrease in elevation in the catchment between the late Miocene and the present. Basin analysis indicates that the decrease in elevation was accomplished by two low-angle detachment faults which root beneath the Zhada basin and exhume mid-crustal rocks. This exhumation results from ongoing arc-parallel extension and provides accommodation for Zhada basin fill. Sequence stratigraphy shows that the basin evolved from an overfilled to an underfilled basin but that further evolution was truncated by an abrupt return to overfilled, incising conditions. This evolution is linked to progressive damming of the paleo-Sutlej River. During the underfilled portion of basin evolution, depositional environments were strongly influenced by Milancovitch cyclicity: particularly at the precession and eccentricity frequencies.
Type:
text; Electronic Dissertation
Keywords:
Arc-parallel Extension; Lacustrine Sequence Stratigraphy; Orbital Cycles; Paleoaltimetry; Tibetan Plateau; Zhada Basin
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
DeCelles, Peter G; Quade, Jay
Committee Chair:
DeCelles, Peter G; Quade, Jay

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleThe Late Miocene through Modern Evolution of the Zhada Basin, South-Western Tibeten_US
dc.creatorSaylor, Joel Edwarden_US
dc.contributor.authorSaylor, Joel Edwarden_US
dc.date.issued2008en_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.abstractThe uplift history of the Tibetan Plateau is poorly constrained in part due to its complex and extended tectonic history. This study uses basin analysis, stable isotope analysis, magnetostratigraphy, detrital zircon U-Pb dating, and paleoaltimetry, and frequency analysis to reconstruct the tectonic, spatial, and environmental evolution of the Zhada basin in southwestern Tibet since the late Miocene. The Zhada Formation, which occupies the Zhada basin and consists of ~ 850 m of fluvial, alluvial fan, eolian, and lacustrine sediments, is undeformed and lies in angular unconformity above Tethyan sedimentary sequence strata. The most negative Miocene δ¹⁸Opsw (paleo-surface water) values reconstructed from aquatic gastropods are significantly more negative than the most negative modern δ¹⁸O(sw) (surface water) values. In the absence of any known climate change which would have produced this difference, we interpret it as indicating a decrease in elevation in the catchment between the late Miocene and the present. Basin analysis indicates that the decrease in elevation was accomplished by two low-angle detachment faults which root beneath the Zhada basin and exhume mid-crustal rocks. This exhumation results from ongoing arc-parallel extension and provides accommodation for Zhada basin fill. Sequence stratigraphy shows that the basin evolved from an overfilled to an underfilled basin but that further evolution was truncated by an abrupt return to overfilled, incising conditions. This evolution is linked to progressive damming of the paleo-Sutlej River. During the underfilled portion of basin evolution, depositional environments were strongly influenced by Milancovitch cyclicity: particularly at the precession and eccentricity frequencies.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectArc-parallel Extensionen_US
dc.subjectLacustrine Sequence Stratigraphyen_US
dc.subjectOrbital Cyclesen_US
dc.subjectPaleoaltimetryen_US
dc.subjectTibetan Plateauen_US
dc.subjectZhada Basinen_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.advisorDeCelles, Peter Gen_US
dc.contributor.advisorQuade, Jayen_US
dc.contributor.chairDeCelles, Peter Gen_US
dc.contributor.chairQuade, Jayen_US
dc.contributor.committeememberKapp, Paulen_US
dc.contributor.committeememberGehrels, Georgeen_US
dc.contributor.committeememberDucea, Mihaien_US
dc.identifier.proquest10043en_US
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