|
>
College of Letters and Science >
Department of Earth Sciences >
Faculty
and Staff
Todd C. Feeley
Associate Professor of Geology
 |
Contact Information
Office: Traphagen Hall #206
Phone: (406) 994-6917
Email:
tfeeley(AT)montana.edu
Education
B.A., University of California, Santa Barbara, 1985
M.S., Oregon State University, 1989
Ph.D., University of California, Los Angeles, 1993
|
Research Interests
My research centers on the behavior of magma in and on the Earth's
crust as deduced from field relationships and the chemical analysis of
rocks and minerals. The broad goal is to further understanding of the
origin and evolution of magmas in crustal reservoirs, their behavior
during volcanic eruptions, and their implications for magmatic,
volcanic, and tectonic processes. The methods I employ include major
and trace element analyses by XRF and ICP-MS, radiogenic isotope
analyses by TIMS, stable isotope analyses by conventional and laser
techniques, and mineral analyses by electron microprobe. My previous
and ongoing research projects include studies of large stratovolcanoes
in the Andean and Cascades volcanic arcs, Cenozoic volcanic fields in
the U.S. Cordillera, and basaltic lava fields in the back-arc of the
Aleutian subduction system.
Through support from the National Science Foundation (EAR-9983769), my
students and I have also been working at Mount St. Helens, where among
other things we have created a self-led geologic trail guide for the
trail linking the Johnston Ridge Observatory to Windy Ridge. Our PDF trail guide is formatted to print
double-sided on a single 11x17 sheet. Crease marks for folding are
marked. This guide will continue to be updated as eruptive activity at
the volcano continues.
Current Graduate Students
Gary
Michelfelder
Selected Publications
Chang, J.M., Feeley, T.C., and DeRaps, M.R.,
2009. Petrogenesis of basaltic volcanic rocks from the Pribilof
Islands, Alaska, by melting of metasomatically enriched depleted
lithosphere, crystallization differentiation, and magma mixing. Journal
of Petrology. 50:2249-2286; doi:10.1093/petrology/egp075
Feeley, T.C., Winer, G.S., 2009.
Volcano hazards and potential
risks on St. Paul Island, Pribilof Islands, Bering Sea, Alaska. Journal
of Volcanology and Geothermal Research 182; 57-66.
Feeley, T.C., Clynne, M.A., Winer, G.S.,
Grice, W.A., 2008. Oxygen Isotope Geochemistry of the Lassen Volcanic
Center, California: Resolving Crustal and Mantle Contributions
to Continental Arc Magmatism. Journal of Petrology 49:971-997;
doi:10.1093/petrology/egn013.
Grunder, A.L., Klemetti, E.W., Feeley, T.C.,
McKee, C.L. 2008. Eleven million years of arc volcanism at the
Auganquilcha Volcanic Cluster, northern Chilean Andes: Impliacations
for the lifespan and emplacement of plutons. Plutons and
Batholiths - Wallace Pitcher Memorial Issue, Transactions of the
Royal Society of Edinburgh: Earth Sciences, 97:415-436.
Feeley, T.C., Wilson, L.F., Underwood, S.J.,
2008. Distribution and Compositions of Magmatic Inclusions in the
Mount Helen Dome, Lassen Volcanic Center, California: Insights into
Mama Chamber Processes. Lithos 106: 173-189.
Winer, G.S., Feeley, T.C., & Cosca,
M.A., 2004. Basaltic volcanism in the Bering Sea: geochronology and
volcanic evolution of St. Paul Island, Pribilof Islands, Alaska.
Journal of Volcanology and Geothermal Research, 134: 277-301.
Feeley, T.C., 2003. Origin and tectonic
implications of across-strike geochemical variations in the Eocene
Absaroka volcanic province, United States. Journal of Geology,
111:329-346.
Feeley, T.C. & Cosca, M.A., 2003. Time
vs. composition trends of magmatism at Sunlight volcano, Absaroka
volcanic province, Wyoming. Geological Society of America Bulletin,
115:714-728.
Lindsay, C.R. & Feeley, T.C., 2003.
Magmagenesis at the Eocene Electric Peak-Sepulcher Mountain complex,
Absaroka Volcanic Province, USA. Lithos 67:53-76.
Feeley, T.C., Cosca, M.A., & Lindsay,
C.R., 2002. Petrogenesis and implications of cryptic hybrid magmas from
Washburn volcano, Yellowstone National Park, USA. Journal of Petrology,
43:663-703
Feeley, T.C. & Winer, G.S., 1999.
Evidence for fractionation of Quaternary basalts on St. Paul Island,
Alaska, with implications for the development of shallow magma chambers
beneath Bering Sea volcanoes. Lithos, 46:661-676.
Feeley, T.C., Dungan, M.A. & Frey, F.A.,
1998. Geochemical constraints on the origin of mafic and silicic magmas
at Cordon El Guadal, Tatara San Pedro complex, Chile. Contributions to
Mineralogy and Petrology, 131:393-411.
Singer, B.S., Wijbrans, J.R., Nelson, S.T.,
Pringle, M.S., Feeley, T.C., & Dungan, M.A., 1998. Inherited argon
in a Pleistocene andesite lava: 40Ar/39Ar
incremental-heating and laser-fusion analyses of plagioclase. Geology,
26:427-430.
Singer, B.S., Thompson, R.A., Dungan, M.A.,
Feeley, T.C., Pickens, J., Brown, L.L., Nelson, S.T., Wulff, A.W.,
Davidson, J.P., & Metzger, J., 1997. Volcanism and erosion during
the past 930 K.Y. at the Tatara-San Pedro complex, Chilean Andes.
Geological Society of America Bulletin, 109:127-142.
Feeley, T.C. & Dungan, M.A., 1996.
Compositional and dynamic controls on mafic-silicic magma interactions
at continental arc volcanoes: evidence from Cordon el Guadal, Tatara
San Pedro Complex, Chile. Journal of Petrology, 37:1547-1577.
Feeley, T.C. & Sharp, Z.D., 1996.
Geochemical and hydrogen isotopic evidence for in situ dehydrogenation
of biotite in silicic magma chambers. Geology, 24:1021-1024.
Feeley, T.C. & Hacker, M.D., 1995.
Intracrustal derivation of Na-rich andesitic and dacitic magmas: an
example from Volcan Ollague, Andean Central Volcanic Zone. The Journal
of Geology, 103:213-216.
Feeley, T.C. & Sharp, Z.D., 1995. 18O/16O
isotope
geochemistry of silicic lava flows erupted from Volcan Ollague,
Andean Central Volcanic Zone. Earth and Planetary Science Letters,
133:239-254.
Feeley, T.C. & Davidson, J.P., 1994.
Petrology of calc-alkaline lavas at Volcan Ollague and the origin of
compositional diversity at central Andean stratovolcanoes. Journal of
Petrology, 35:1295-1340.
Feeley, T.C., 1993. Crustal modification
during subduction-zone magmatism: evidence from the southern Salar de
Uyuni region (20o-22oS), central Andes. Geology,
21:1019-1022.
Feeley, T.C., Davidson, J.P., &
Armendia, A., 1993. The volcanic and magmatic evolution of Volcan
Ollague, a high-K, late Quaternary stratovolcano in the Andean Central
Volcanic Zone. Journal of Volcanology and Geothermal Research,
54:221-245.
Feeley, T.C. & Grunder, A.L., 1991.
Mantle contribution to the evolution of Middle Tertiary silicic
magmatism during early stages of crustal extension: The Egan Range
volcanic complex, east-central Nevada. Contributions to Mineralogy and
Petrology, 106:154-169.
|
