Calibration of Rutile (U-Th)/He Thermochronology: assessing the thermal evolution of the KTB drill hole, Germany and adjacent Bohemian Massif
Issue Date
2009-05-12Author
Wolfe, Melissa Renee
Publisher
University of Kansas
Format
196 pages
Type
Thesis
Degree Level
M.S.
Discipline
Geology
Rights
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
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Show full item recordAbstract
This study empirically calibrates zircon and rutile (U-Th)/He dating by evaluating the experimentally-derived He diffusion kinetics and their extrapolation over geological time by (U-Th)/He dating a suite of borehole samples with a welldefined thermal history. Age dating is coupled with cycled step-heating diffusion experiments and thermal modeling of zircon and rutile. The German Continental Deep Drilling Project (KTB) is ideally suited for this approach given its depth and zircon- and rutile-bearing metamorphic rocks. Results from zircon (U-Th)/He
analyses display a helium partial retention zone between ~140-210°C which agrees well with laboratory-derived He diffusion kinetics. While regional rutile (U-Th)/He age data confirm the feasibility of rutile (U-Th)/He thermochronometry (Tc ≈ 220°C) in eclogites and granulites, anomalous rutile (U-Th)/He ages from the KTB drill hole illustrate the implications of retrograde rutile breakdown to titanite and the importance of petrographic characterization of rutile for obtaining reliable and meaningful thermochronometric data.
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- Geology Dissertations and Theses [232]
- Theses [3940]
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