Its relatively stability under a variety of geological conditions, and resilience to radiation damage, make monazite a reliable geochronometer (Harrison et al., 2002).Early work on monazite showed large discrepancies between U-Pb and Th-Pb ages (Tilton and Nicolaysen, 1957), which were explained by Pb diffusion over significant and time (Shestakov, 1969), or by Pb loss (Michot and Deutsch, 1970).
He is also an Adjunct Professor of Astronomy, at the University of Maryland and an Adjunct Professor of Astronomy & Astrophysics at Pennsylvania State University.
This is why zircon geochronology and thermochronology is a particularly useful approach to detrital studies.
In cases where different sources are characterized by the same zircon U-Pb ages, differential metamorphism and/or exhumation may produce distinctive thermochronological ages.
Overall, the advancement of new approches and analytical techniques such as the one described by Hietpas et al., double and triple dating (e.g., Rahl., et al., 2003; Bernet et al., 2006; Carrapa et al., 2009), and geochronology combined with geochemical analysis (Flowerdew et al., 2007) of detrital minerals, open uncharted pathways into the complex tectono-thermal histories recorded by clastic material.
) at which the system became fully retentive (closed) depends on various parameters such as compositions, thermal history, and pressure, and on the details of diffusion.
He is a research scientist in gamma-ray astronomy active in instrument development and data analysis.