Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


27960.pdf (9.17 MB)

ETD Abstract Container

Abstract Header

Quantifying Age and Rate of Landscape and Paleoenvironmental Change in Arid Tectonic Environments using Terrestrial Cosmogenic Nuclides: The Interplay of Climatic vs. Tectonic Drivers of Landscape Evolution in Arid Regions

Hedrick, Kathryn
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504869385627475

Abstract Details

2017, PhD, University of Cincinnati, Arts and Sciences: Geology.
Models attempting to define the links among climate, tectonics, erosion, and topography in high mountain environments have continued to evolve in recent years. Quantitative studies of the rates of catchment and bedrock erosion and the ages of significant depositional or erosional events are still needed to illuminate these complex links and their positive and negative feedbacks. Underlying climatic and tectonic forcings may exert significant control on the interplay of surface and tectonic processes and how mountain landscape systems develop. Regional variability poses an additional challenge to researchers in environments that are already dynamic and complex. To investigate how the interplay of these tectonic and climatic factors affect arid, mountainous regions and how they have affected the evolution of landscapes in mountain systems during the Quaternary, I present quantitative data bearing on the ages of moraines, strath and fluvial terraces, and alluvial fan surfaces using 10Be terrestrial cosmogenic nuclide (TCN) methods in the Pamir Range of western China and the Precordillera of Argentina, where optically-stimulated luminescence (OSL) dating was also applied. 10Be TCN methods were also used to determine catchment and bedrock erosion rates for a part of the Zanskar Range in the Indian Himalaya. My study examines the ages of these landforms within the context of each field area’s climatic and tectonic setting. Dating and erosion results were analyzed within their geologic context, building a whole-basin sedimentary history in China, a regional climatic framework in Argentina, and a line between erosion rates and basin morphology and tectonics in India. In the Pamir Himalaya, results illustrate the presence of remarkably well-preserved alluvial fan surfaces dating back to ~580 ka, despite evidence of significant Quaternary basin change, including the development and drainage of a large paleolake and multiple glaciations since >80 ka. In the Zanskar Himalaya, notably low erosion rates of both basins and bedrock rival those of hyper-arid desert regions. In the Precordillera of Argentina, results indicate erosion is highest in active stream channels and hillslopes and lower on alluvial fan and strath terrace surfaces compared to bedrock, with erosion occurring most slowly on longest-abandoned fan surfaces. These results suggest three key findings: 1) There is high potential for long-term landform and landscape stability in arid mountain regions; 2) Erosion rates and landscape change in high-altitude arid environments may still be driven primarily by climatic agents (e.g., periglacial processes); and 3) Broad regional correlation of alluvial fan surface ages allows us to determine climate as the dominant forcing factor in some arid, tectonically active regions. In detail, my studies illustrate the complexity and potential for variability in how arid and semi-arid mountain systems and adjacent forelands evolve and the sensitivity of these landscapes and their development to change. The results provide new quantitative data to further our understanding of these linked mountain systems, but indicate that in order to fully understand the interplay between various processes at work more research needs to be done.
Lewis Owen, Ph.D. (Committee Chair)
Marc Caffee, Ph.D. (Committee Member)
Craig Dietsch, Ph.D. (Committee Member)
Thomas Rockwell, Ph.D. (Committee Member)
Lindsay Schoenbohm, Ph.D. (Committee Member)
300 p.
Geology
Geology; Geomorphology; Cosmogenic dating; Tectonic Geomorphology

Recommended Citations

Citations

  • Hedrick, K. (2017). Quantifying Age and Rate of Landscape and Paleoenvironmental Change in Arid Tectonic Environments using Terrestrial Cosmogenic Nuclides: The Interplay of Climatic vs. Tectonic Drivers of Landscape Evolution in Arid Regions [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504869385627475

    APA Style (7th edition)

  • Hedrick, Kathryn. Quantifying Age and Rate of Landscape and Paleoenvironmental Change in Arid Tectonic Environments using Terrestrial Cosmogenic Nuclides: The Interplay of Climatic vs. Tectonic Drivers of Landscape Evolution in Arid Regions. 2017. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504869385627475.

    MLA Style (8th edition)

  • Hedrick, Kathryn. "Quantifying Age and Rate of Landscape and Paleoenvironmental Change in Arid Tectonic Environments using Terrestrial Cosmogenic Nuclides: The Interplay of Climatic vs. Tectonic Drivers of Landscape Evolution in Arid Regions." Doctoral dissertation, University of Cincinnati, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504869385627475

    Chicago Manual of Style (17th edition)

ucin1504869385627475
449
© 2017, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.