Metamorphic Petrology List server members,
Please encourage students interested in lab and field-oriented hard-rock
petrology to apply for a research assistantship (a full tuition waiver and
$10,900 academic year stipend) toward a M.Sc. degree at Vanderbilt
University to work on the project described below.
Thanks,
John C. Ayers
Laboratory and Field Investigations of Monazite Paragenesis, Growth
Kinetics, Textural Development, and U-Th-Pb Chronometry in Igneous and
High-Grade Metamorphic Rocks
Monazite grains in igneous and high-grade metamorphic rocks often contain
multiple growth zones that yield U,Th-Pb dates corresponding to multiple
events in the history of a rock. The proposed lab and field experiments are
designed to characterize monazite growth and recrystallization. In-situ
measurements of textural features, ages, and compositions of growth zones in
natural monazites collected from regions with well-characterized histories
(a pluton in southern Nevada, metamorphic terranes in North Carolina and
California) will help to establish the timing and conditions of monazite
growth. Lab experiments conducted under similar conditions will quantify
growth mechanisms and rates and corroborate textural interpretations of
zoning in natural monazites. Because growth and recrystallization often
appears to be related to fluid influx, experiments on rocks containing
monazite and fluid will help to identify characteristic textural features of
hydrothermal growth and recrystallization including crystal size
distributions, zoning patterns, inclusion/host relations, and wetting
angles. The dependence of these features on fluid composition, host grain
size and coarsening rate, and temperature will also be investigated to
identify conditions of growth of natural monazites. Results will refine
interpretations of texture and zoning in natural monazites and the
correlation of measured U,Th-Pb monazite ages with specific geochemical and
tectonic events.
For more information, contact:
Dr. John C. Ayers
Associate Professor
Department of Geology
Vanderbilt University
P.O. Box 105, Station B
Nashville, TN 37235
Phone: (615) 322-2158
FAX: (615) 322-2138
email: [log in to unmask]
web: http://geo.cas.vanderbilt.edu/users/Ayers/Web/Ayers/
or:
Professor Calvin Miller
Department of Geology
Vanderbilt University
P.O. Box 105, Station B
Nashville, TN 37235
Phone: (615) 322-2232
FAX: (615) 322-2138
email: [log in to unmask]
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