Tectonic, Climate, and Erosional Controls on Andean Plateau Incision and Width, South Peru
Final Report Abstract
In this collaborative project, we contributed across-strike data on (i) timing and magnitude of exhumation, (ii) structural geometries, and (iii) thermokinematic histories to evaluate drivers of eastern Andean Plateau exhumation and incision. Results show that the first-order thermochronometric age pattern is a function of rocks' vertical and lateral movement over basement ramps and resulting exhumational erosion. This pattern is superimposed with a regional and synchronous incision-related exhumation signal since the Pliocene. While this incision occurred independent of structural deformation, the exhumation magnitude and difference in interfluve and canyon thermochronometric ages require the presence of a tectonic contribution to exhumation. We conclude that uplift over a basement ramp in the Eastern Cordillera and a decrease in shortening rates since ~10 Ma set the stage for climate-enhanced incision to occur in southern Peru. Overall, I deem the project a success. The strength of this project was the combined expertise from different disciplines, broad sampling approach, and integration of various datasets. Our findings will guide future research in the eastern Central Andes and impact similar studies elsewhere. In most parts, the project developed according to plan. In parts, progress was slowed down by the corona pandemic, which particularly affected the analytical portion of the US collaborators' project. However, independent of that slowdown, the timely completion of all the project goals would have been more achievable with one less transect.
Publications
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Along-strike variations in the timing of exhumation in the eastern Peruvian Andes. GeoKarlsruhe 2021, Virtual conference, Deutsche Geologische Gesellschaft - Geologische Vereinigung E.V. (DGGV).
Falkowski, S. & Ehlers, T.A.
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Along-strike variations in the timing and magnitude of exhumation in the eastern Peruvian Andes.
Falkowski, Sarah; Ehlers, Todd; McQuarrie, Nadine; Buford, Parks Victoria; Glover, Chloë & Cárdenas, José
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Assessing Drivers of High Exhumation Magnitudes and Young Cooling Ages in the Southern Peruvian Andes (13-18° S). AGU Fall Meeting 2022, Chicago, USA, 12–16 December 2022, T52A-03.
Glover, Chloë O.; McQuarrie, Nadine; Falkowski, Sarah & Ehlers, Todd A.
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Assessing drivers of high exhumation magnitudes and young cooling ages in the eastern central Andes, southern Peru (13–18°S). Earth and Planetary Science Letters, 620, 118281.
Glover, Chloë O.; McQuarrie, Nadine; Falkowski, Sarah & Ehlers, Todd A.
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Drivers of eastern Andean Plateau incision from integrated thermochronology and thermo-kinematic modelling.
Falkowski, Sarah; Glover, Chloë; Buford, Parks Victoria; McQuarrie, Nadine; Perez, Nicholas & Ehlers, Todd A.
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Drivers of eastern Andean Plateau incision from integrated thermochronology and thermokinematic modelling. Thermo2023, 18th International Conference on Thermochronology, Riva del Garda, Italy, 3–8 September 2023.
Falkowski, S., Glover, C., Buford Parks, V., McQuarrie, N., Perez, N. & Ehlers, T.A.
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Exhumation and incision of the eastern Central Andes, southern Peru: Low-temperature thermochronology observations. Earth and Planetary Science Letters, 620, 118299.
Falkowski, Sarah; Ehlers, Todd A.; McQuarrie, Nadine; Glover, Chloë O.; Perez, Nicholas D. & Buford, Parks Victoria M.
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Low-temperature thermochronometric data (AHe, AFT, ZHe, ZFT) from three bedrock sample transects across the eastern Central Andes, southern Peru. PANGAEA
Falkowski, S. & Ehlers, T.A.
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Timing and drivers of exhumation and sedimentation in the eastern Peruvian Andes: Insights from thermokinematic modelling. Earth and Planetary Science Letters, 620, 118355.
Buford, Parks Victoria M.; McQuarrie, Nadine; Falkowski, Sarah; Perez, Nicholas D. & Ehlers, Todd A.
