Citation
Li, Haoyu (2024) Revisiting U-Pb and ²⁶Al-²⁶Mg Systematics of Calcium Aluminum-Rich Inclusions: Applications on Early Solar System Chronology and Evolution History. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ahbv-8z61. https://resolver.caltech.edu/CaltechTHESIS:05202024-220724726
Abstract
Stable isotope systematics are powerful tools for understanding the evolution history of the earth and Solar system. In this thesis, I present applications of uranium (U) and magnesium (Mg) isotopes in both geochemistry and cosmochemistry.
Uranium is a redox-sensitive to the dissolved oxygen level in aqueous environment, and these redox reactions are associated with resolvable isotopic fractionation. Thus, U isotopes are widely used in paleo-environment reconstruction as a proxy of marine anoxia. For this application, the work presented in this thesis includes (1) exploration of the potential of bioapatite as a novel paleoredox proxy. and (2) re-calibrate the U isotope composition of seawater. The U-Pb and Al-Mg systematics provide constraints on the time sequence and composition of the early Solar System. For this application, the work presented in this thesis includes (1) combined Pb-Pb and Al-Mg systematics on calcium-aluminum-rich inclusions (CAIs) to resolve the discrepancies between these two chronometers (2) Al-Mg systematics of bulk CAIs to understand their precursors. This thesis also presents the analytical techniques developed for the studies above and the development of a comprehensive uranium isotope database.
Item Type: | Thesis (Dissertation (Ph.D.)) | |||||||||||||||
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Subject Keywords: | uranium isotopes, magnesium isotope, paleoredox, early Solar System | |||||||||||||||
Degree Grantor: | California Institute of Technology | |||||||||||||||
Division: | Geological and Planetary Sciences | |||||||||||||||
Major Option: | Geochemistry | |||||||||||||||
Thesis Availability: | Restricted to Caltech community only | |||||||||||||||
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Defense Date: | 16 May 2024 | |||||||||||||||
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Record Number: | CaltechTHESIS:05202024-220724726 | |||||||||||||||
Persistent URL: | https://resolver.caltech.edu/CaltechTHESIS:05202024-220724726 | |||||||||||||||
DOI: | 10.7907/ahbv-8z61 | |||||||||||||||
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Default Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | |||||||||||||||
ID Code: | 16402 | |||||||||||||||
Collection: | CaltechTHESIS | |||||||||||||||
Deposited By: | Haoyu Li | |||||||||||||||
Deposited On: | 04 Jun 2024 20:32 | |||||||||||||||
Last Modified: | 04 Jun 2024 20:32 |
Thesis Files
PDF
- Final Version
Restricted to Caltech community only until 4 December 2024. See Usage Policy. 19MB |
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