Parks, Victoria Marcelyn Buford
(2021)
Quantifying Timing and Rate of Deformation and Exhumation in the Central Andes: Insights from Thermokinematic and Landscape Models of Balanced Cross-Sections.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
In the central Andes, we couple detailed, sequentially deformed, forward modelled, balanced cross-sections, including flexural isostasy and erosion, with advection-diffusion thermal models (Pecube) and a physics-based surfaces processes model (CASCADE) in order to provide insight on the structural and morphological history evolution. Preserved basin histories in the Altiplano, along with geologic mapping and thermochronology sampling, assist in constraining the location and timing of exhumation, topographic development, and the geometry of active faulting. Thin-skinned surface exposures of Paleozoic folded and faulted rocks are balanced at depth by long basement thrust sheets. These basement thrust sheets, and their associated ramps, are the first-order control on cooling age patterns in the central Andes, as shown through our Pecube modelling. Incision level also has an important impact on the suite of thermal ages measured, and our new methodology allows us to synchronously track and thermally model interfluve and canyon elevations. We additionally use our sequentially deformed cross-section as the kinematic input to landscape evolution models, which apply realistic hillslope and fluvial erosion based on a suite of erosional and climatic patterns to produce a landscape based on the cross-section geometry and kinematics. Extracting geomorphic indices of uplift (eg river channel steepness, Ksn) from the modeled topography and comparing the modelled to modern-day, remotely acquired, Ksn, we are able to link these surface uplift indicators with subsurface geometry that can reproduce those metrics. We can trace the regional Ksn pattern to gain insight into the regional subsurface geometry and thus better locate active, or recently active, faults in the region along strike. The combination of traditional structural techniques, such as kinematically and flexurally sequentially modelled balanced cross-sections, and newer techniques of thermal and landscape modelling allow us to investigate the geomorphic response of viable thermo-kinematic models and derive potential regional variations in and along strike subsurface geometry and kinematics.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
20 January 2021 |
| Date Type: |
Publication |
| Defense Date: |
20 November 2020 |
| Approval Date: |
20 January 2021 |
| Submission Date: |
19 November 2020 |
| Access Restriction: |
2 year -- Restrict access to University of Pittsburgh for a period of 2 years. |
| Number of Pages: |
382 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Geology and Planetary Science |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
thermokinematic modelling
landscape modelling
thermal modelling
Andes
fold and thrust belt |
| Date Deposited: |
20 Jan 2021 19:03 |
| Last Modified: |
20 Jan 2023 06:15 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/39906 |
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