Thesis
Cratons Through the Ages: Impact of Rayleigh Number on Craton Shape
Washington State University
Master of Science (MS), Washington State University
2023
DOI:
https://doi.org/10.7273/000005105
Abstract
Cratonic lithosphere contains crucial details about planetary dynamics on Earth and understanding the shape of cratonic lithosphere may provide new insight into their history. Seismic imaging suggests that there are various margin shapes of the present day cratonic lithosphere, including regions with vertical or sloped margins. While prior studies have investigated the impact of viscosity, buoyancy, and intrinsic yield strength of cratonic lithosphere, there have been limited studies on the impact of cratonic lithosphere shape, particularly within changing mantle dynamics. This study investigates the influence of changing mantle dynamics, as represented by the Rayleigh number, on the shape of cratonic lithosphere. We used insights from numerical simulations to determine if different observed cratonic lithosphere shapes are long-lived and indicative of their original formation or if some shapes are the result of post-formation deformation. Our study suggests that cratonic lithosphere shape is an important, but secondary factor in cratonic lithosphere stability with changing Rayleigh number and that cratonic lithosphere viscosity contrast remains the primary driver. We also find that cratonic lithosphere with sloped margins can be maintained after initial craton formation billions of years ago, but that shape can also be formed as cratonic lithosphere with different initial shape evolves. As such, caution should be used when interpreting modern-day images of cratonic lithosphere structure and shape.
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Details
- Title
- Cratons Through the Ages: Impact of Rayleigh Number on Craton Shape
- Creators
- Alexus Chanel Richardson
- Contributors
- Catherine Cooper (Advisor)Jeffrey D. Vervoort (Committee Member)Sean P Long (Committee Member)C. Kent Keller (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Environment, School of the (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 71
- Identifiers
- 99901019935901842
- Language
- English
- Resource Type
- Thesis