Ph.D. student since Fall 2012
Madison is working with quartz-hosted melt inclusions from large-volume, crystal-rich ignimbrites of the southern Rocky Mountain San Juan volcanic field, Colorado. These ignimbrites represent some of the largest volcanic eruptions on Earth, as individual eruptions involved thousands of cubic kilometers of what is thought to represent remobilized granodioritic plutons erupted from very large calderas. The goal is to understand how such large bodies of nearly solidified magma become rapidly reheated and recharged with volatiles to make them eruptible. To solve this, the use of trace elements and volatiles in quartz-hosted melt inclusions, together with cathodoluminescence zonation imagery, will be used to provide a record of magmatic processes and compositions present before reheating. These can then be compared to reentrants and external matrix glass to get a record of changing conditions during the reheating and remobilization processes that eventually led to eruption.
M.S. student since Fall 2011
James' research involves using olivine melt inclusions to better constrain across-arc (west to east) variations in magmatic volatiles in the southern Washington Cascades. This work is important for improving our understanding of the subduction processes that control magma generation and hydration, which ultimately drive volcanic eruptions. In support of this research, James will be conducting fieldwork around Mount St. Helens, Mt. Adams and the Simcoe Mountains Volcanic Field.
M.S. student since Fall 2011
Robin is interested in the eruption dynamics of basaltic volcanism, specifically the role of water and carbon dioxide in driving energetic lava fountains. Robin's research is focused on the 1959 Kilauea Iki eruption and the 1960 Kapoho eruption of Kilauea Volcano, Hawai'i. Robin will be using melt inclusions to measure the true carbon dioxide composition and then calculate the storage/formation pressure of Kilauea olivine crystals. Robin will use an experimental furnace technique to rehomogenize melt inclusions by redissolving carbon-dioxide rich shrinkage bubbles at high temperature and then rapidly quenching the host olivine crystals. Robin will measure volatile contents of these rehomogenized inclusions with the FTIR and the electron microprobe.
M.S. student since Fall 2010
Lucy uses geochemical tools to quantify the release of harmful aerosols during Holocene explosive cinder cone eruptions in the Central and Southern Cascades (OR: Collier Cone, Yapoah Crater, Garrison Butte, Four-in-One Fissure; CA: Cinder Cone, Basalt of Railroad Grade and Basalt of Highway 44). To measure such aerosols she analyzes dissolved volatiles trapped within olivine-hosted melt inclusions and quenched tephra groundmass glass. She hopes this research can improve real-time assessment of volcanic hazards that local Cascades communities may face during a future cinder cone eruption.
Ph.D. student since Fall 2010
Kristina is a PhD student who works on melt inclusions from primitive magmas in the Cascade Arc. Her current work focuses on cross-arc variations in volatile and trace elements in olivine-hosted melt inclusions (acquired using FTIR, EPMA, and LA-ICP-MS) from cinder cones in the Lassen region of Northern California to understand the influence of subducting warm oceanic lithosphere on dehydration reactions in the slab and melt production in the mantle wedge. She also uses melt inclusion data to inspect the plumbing systems of individual monogenetic cones, such as Cinder Cone (which erupted ~1666). Her research in the near future will also include experimentally growing quartz-hosted melt inclusions from a hydrous rhyolitic melt.
Stephanie used experimental techniques to study mantle melting in subduction zones. She used piston-cylinder apparatus to conduct hydrous rock-melting experiments at pressures up to 2.5 GPa and temperatures to 1350 C. The majority of her work focused on primitive lavas that erupted along the Trans-Mexican Volcanic Belt but she has also studied primitive basalts from the Aleutian Islands. Stephanie received her MS at University of Oregon under the guidance of Dana Johnston, who also co-advised her PhD work. Stephanie now works for ExxonMobil Exploration Company in Houston, TX.
Publications (with Paul):
Weaver, S.L., Wallace, P.J., and Johnston, A.D. (2011) A comparative study of continental vs. intraoceanic arc mantle melting: Experimentally determined phase relations of hydrous primitive melts. Earth and Planetary Science Letters, 308 (1-2), 97-106
Stan began his geological vocation in the Blue Ridge mountains of the Appalachians mapping Neo-Proterozoic meta-volcanics as an undergraduate. As a Masters student, he uses olivine-hosted melt inclusions to calculate crystallization pressures inside Oregon Cascade shield volcanoes. His primary field sites, Belknap Crater, Mount Washington, and North Sister, represent shields of varying ages and magma type. Using the volatile data, he intends to distinguish the magmatic plumbing systems of the Cascade shield volcanoes from those of the Cascade cinder cones.
Laboratory Manager, Earth & Environmental Sciences, Rensselaer Polytechnic Institute, Troy NY 12180.
Adjunct Faculty, Department of Geological Sciences, University of Oregon
Assistant Professor, Instituto Politecnico Nacional (IPN), Mexico, D.F.
Honors Thesis, 2012
Cascade Arc Magma Genesis: Volatile and Major Element Indicators in Primitive Basalts from
the Lassen Region
Dan studied magma generation processes in the Cascades utilizing olivine-hosted melt inclusions. The ultimate aim of his study was to investigate the role of slab-derived H2O in generating Cascade arc magmas. His research involved obtaining volatile (H2O, CO2, S, Cl, F) and major element compositions of a calc-alkaline basalt and a low-K tholeittic basalt erupted from monogenetic vents in the Lassen Region of Northern CA. This required field work near Lassen Peak and melt inclusion preparation and analysis using FTIR spectroscopy and EPMA. His data will be added to a growing database of volatile and major element contents of primitive magmas to better understand along arc trends.