Kinematic and flexural isostasy modeling in central nepal: using erosional, depositional, and cooling histories to validate a balanced cross section

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dc.contributor McQuarrie, Nadine
dc.contributor Goodliffe, Andrew M.
dc.contributor Wielicki, Matthew M.
dc.contributor.advisor Robinson, D. M.
dc.contributor.author Olree, Elizabeth
dc.date.accessioned 2018-07-11T16:49:14Z
dc.date.available 2018-07-11T16:49:14Z
dc.date.issued 2018
dc.identifier.other u0015_0000001_0002953
dc.identifier.other Olree_alatus_0004M_13397
dc.identifier.uri http://ir.ua.edu/handle/123456789/3638
dc.description Electronic Thesis or Dissertation
dc.description.abstract Balanced cross sections present valid and admissible interpretations of surface and subsurface data. Thermochronologic and foreland basin provenance data are other aspects that must be adhered to when producing balanced cross sections. If a cross section is balanced, there is an implicit kinematic sequence that will produce the illustrated geometry, allowing the production of a kinematic forward model of deformation beginning with the original pre-deformation geometry. I produced a new balanced cross section in central Nepal through the Himalayan thrust belt from hinterland to foreland and forward modeled the cross section in 2D Move. A kinematic forward model illustrates the sequence of displacement on each fault; however, it does not include the effects on the basal decollement from flexure of the Indian plate due to loading, erosion of topographic relief, or isostatic rebound due to erosion. To address these shortcomings, a multi-step reconstruction was applied to the balanced cross section in 2D move that accounts for the loading of the Indian lithosphere as thrusts faults displace topography. This thrust induced load increases the dip of the basal decollement as a flexural response of the Indian crust after loading. As deformation propagates toward the foreland, the topographic profile evolves and the foreland basin migrates forelandward of the deformation front, increasing in stratigraphic thickness over time due to subsidence and resulting deposition of sediment eroded from the hinterland. The timing of erosional unroofing and deposition implied by the flexural isostasy model is inconsistent with provenance data from the foreland basin, suggesting that the implied kinematic sequence is not viable or that new timing constraints should be chosen. Because the thrust belt experienced rapid shortening, the subsurface thermal structure is too complex to estimate cooling ages from the flexural isostasy model using a constant geothermal gradient. Cooling ages should be modeled using thermokinematic modeling software to determine the evolution of the thrust belt thermal structure.
dc.format.extent 101 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.ispartof The University of Alabama Libraries Digital Collections
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated.
dc.subject.other Geology
dc.subject.other Geophysics
dc.subject.other Geomorphology
dc.title Kinematic and flexural isostasy modeling in central nepal: using erosional, depositional, and cooling histories to validate a balanced cross section
dc.type thesis
dc.type text
etdms.degree.department University of Alabama. Dept. of Geological Sciences
etdms.degree.discipline Geology
etdms.degree.grantor The University of Alabama
etdms.degree.level master's
etdms.degree.name M.S.


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