The U-Pb system is an underappreciated tool for understanding the thermal evolution of the lithosphere. Minerals such as apatite, rutile, and titanite have closure temperatures between about 400 and 650 ˚C, making this method ideal for calibration middle- to lower-crustal thermal structure as a function of time, and fill a major temperature gap left by 40Ar/39Ar, Rb-Sr, and (U-Th)/He dating methods. Using these methods combined, one can determine the temperature history of a rock from the lower crust to the surface, allowing precise calibration of tectonic, metamorphic, and surficial processes. As with the other thermochronological methods, determining robust thermal histories using U-Pb dating requires a detailed understanding of how diffusion of the daughter product controls the recorded dates and how to evaluate other forms of open-system behavior. This involves integrating mineral characterization via imaging and geochemical microanalytical techniques in combination with numerical modeling.
Areas of research:
- thermal structure of mountain belts
- exhumation and preservation of Archean cratons
- diffusion of Pb in U-rich minerals
- the importance of recrystallization and metamorphism in U-Pb thermochronology