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dc.contributor.advisorDeCelles, Peter G.en_US
dc.contributor.authorLeier, Andrew
dc.creatorLeier, Andrewen_US
dc.date.accessioned2011-12-05T22:03:20Z
dc.date.available2011-12-05T22:03:20Z
dc.date.issued2005en_US
dc.identifier.urihttp://hdl.handle.net/10150/193796
dc.description.abstractThe Tibetan plateau is arguably the most important geological feature on Earth, yet its formation and evolution are poorly understood. This investigation utilizes Cretaceous sedimentary strata exposed in the Lhasa terrane of southern Tibet in order to constrain the paleogeography and tectonic setting of the region prior to the Indo-Asian collision. Lower Cretaceous strata consist of clastic sedimentary units that were deposited in shallow marine and fluvial environments. In northern Lhasa these sediments were deposited in a peripheral foreland basin that formed in response to the Lhasa-Qiangtang collision. The lower Cretaceous sediments in southern Lhasa are quartzose and were derived from cover strata exposed by local uplifts. A marine limestone of Aptian-Albian age overlies the lower Cretaceous clastic strata and was deposited in a shallow continental seaway. The paleogeography of the Lhasa terrane during deposition of the carbonate units was dominated by the effects of the Lhasa-Qiangtang collision, although other conditions, such as a high eustatic sea-level, influenced sedimentation as well. The Upper Cretaceous Takena Formation is composed of a basal member of marine limestone and an overlying member of fluvial red beds. The arkosic strata of the Takena Formation were deposited in a retro-arc foreland basin that formed to the north of the Gangdese magmatic arc. Collectively, the Cretaceous sedimentary strata indicate significant tectonic activity occurred in southern Tibet prior to the Indo-Asian collision. Moreover, the data suggest the crust of southern Tibet was thickened and possibly at high elevations before the Cenozoic.
dc.language.isoENen_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.subjectTibeten_US
dc.subjectTakenaen_US
dc.subjectSedimentologyen_US
dc.subjectDetrital Zirconen_US
dc.subjectOsmiumen_US
dc.subjectMegafanen_US
dc.titleThe Cretaceous Evolution of the Lhasa Terrane, Southern Tibeten_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.contributor.chairDeCelles, Peter G.en_US
dc.identifier.oclc137355124en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberDeCelles, Peter G.en_US
dc.contributor.committeememberKapp, Paulen_US
dc.contributor.committeememberQuade, Jayen_US
dc.contributor.committeememberGehrels, Georgeen_US
dc.contributor.committeememberZandt, Georgeen_US
dc.identifier.proquest1340en_US
thesis.degree.disciplineGeosciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePhDen_US
refterms.dateFOA2018-04-26T12:33:35Z
html.description.abstractThe Tibetan plateau is arguably the most important geological feature on Earth, yet its formation and evolution are poorly understood. This investigation utilizes Cretaceous sedimentary strata exposed in the Lhasa terrane of southern Tibet in order to constrain the paleogeography and tectonic setting of the region prior to the Indo-Asian collision. Lower Cretaceous strata consist of clastic sedimentary units that were deposited in shallow marine and fluvial environments. In northern Lhasa these sediments were deposited in a peripheral foreland basin that formed in response to the Lhasa-Qiangtang collision. The lower Cretaceous sediments in southern Lhasa are quartzose and were derived from cover strata exposed by local uplifts. A marine limestone of Aptian-Albian age overlies the lower Cretaceous clastic strata and was deposited in a shallow continental seaway. The paleogeography of the Lhasa terrane during deposition of the carbonate units was dominated by the effects of the Lhasa-Qiangtang collision, although other conditions, such as a high eustatic sea-level, influenced sedimentation as well. The Upper Cretaceous Takena Formation is composed of a basal member of marine limestone and an overlying member of fluvial red beds. The arkosic strata of the Takena Formation were deposited in a retro-arc foreland basin that formed to the north of the Gangdese magmatic arc. Collectively, the Cretaceous sedimentary strata indicate significant tectonic activity occurred in southern Tibet prior to the Indo-Asian collision. Moreover, the data suggest the crust of southern Tibet was thickened and possibly at high elevations before the Cenozoic.


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