Dr. Wendy A. Bohrson

Ph.D. 1993, University of California at Los Angeles

Professor
Department of Geological Sciences
Central Washington University
Ellensburg, WA 98926-7418
office:509. 963-2835
fax:509.963-2821
bohrson@geology.cwu.edu


Research

Current Interests, Projects and Research Students:

Wendy integrates investigations of the physics and chemistry of magmas to understand how magma bodies evolve. By combining field, analytical, and theoretical modeling studies, she documents the changes in magma properties as melts rise from their mantle source regions (~100 km depth) to Earth's surface.

An important component of her research is documentation of the chemical and physical changes that magmas experience while stored in a magma plumbing system and en route to the surface. One approach that Bohrson uses to better understand how magma bodies evolve is to integrate crystal size distribution analysis, Nomarski imaging, electron microprobe analysis and laser ablation studies. Current projects include studies at Mt. Etna, Crater Lake, Rainier, Mt. Bachelor and Mt. St. Helens.

Her current project involves documenting and modeling magma evolution at Filicudi, Alicudi, and Salina, three islands in the Aeolian Islands of Italy. This work is in collaboration with Drs. Frank Spera and Benedetto DeVivo.

Additional studies involve development and use of the computational code Energy-Constrained Recharge, Assimilation and Fractional Crystallization (EC-RAFC) to document the evolution of magma bodies as they undergo open-system processes. More information about EC-RAFC can be found at the following link.

A new generation of computation model is now under development. The Magma Chamber Simulator combines the major element and phase equilibria constraints of MELTS (Ghiorso and Sack, 1995) with the energy-constrained philosophy and trace element/isotope capabilities of EC-RAFC. This project is a collaboration among Bohrson, Frank Spera and Mark Ghiorso. A proto-type of the Magma Chamber Simulator is almost complete. Check back for updates on this powerful new quantitative tool.

Michelle Tebbe, Aaron Mayfield, Rachel Hunt, and Michelle Harris are currently doing MS theses under Bohrson's supervision, and Brad Pitcher is completing a research project on Mt. Etna.


Background

Bohrson received her Ph.D. from UCLA in 1993. From 1994-1998, she held a University of California Office of the President Postdoctoral Fellowship and a National Science Foundation Postdoctoral Fellowship, and was employed in the Department of Geological Sciences at the University of California, Santa Barbara as a researcher and lecturer.

At Central Washington University, Bohrson has been the Director of the Office of Undergraduate Research (2000-2003), and the Interim Director of Unviersity Research (2002-2003). She is currently the Director of the CWU Science Talent Expansion Program.


Selected Publications

•Salisbury MJ, Bohrson WA, Clynne M, Ramos FC, Hoskin P, 2008, Origin of the 1915 Lassen Peak eruption by magma mixing: Evidence for formation of chemically distinct plagioclase populations from crystal size distribution and in situ chemical data, Journal of Petrology, doi: 10.1093/petrology/egn045.

• Bohrson, W. A., and F. J. Spera, 2007, Energy-Constrained Recharge, Assimilation, and Fractional Crystallization (EC-RAXFC): A Visual Basic computer code for calculating trace element and isotope variations of open-system magmatic systems, Geochem. Geophys. Geosyst., 8, Q11003, doi:10.1029/2007GC001781.

•Spera, FJ, Bohrson WA, Till CB, Ghiorso MS, 2007, Partitioning of Trace Elements among Coexisting Crystals, Melt and Supercritical Fluid during Isobaric Fractional Crystallization and Fractional Melting, American Mineralogist 92: 1881-1898.

•Bohrson WB, 2007, (INVITED), Insight into subvolcanic magma plumbing systems, Geology 35: 767-768.

•Fowler, SJ, Spera FJ, Bohrson WA, Belkin HE, De Vivo B, 2007, Phase Equilibria Constraints on the Chemical and Physical Evolution of the Campanian Ignimbrite, Journal of Petrology 48: 459-493.

•Bohrson WA, Spera FJ, Fowler SJ, Belkin HE, DeVivo B, Rolandi G, 2006, (INVITED), Petrogenesis of the Campanian Ignimbrite: Implications for Crystal-Melt Separation and Open-System Processes from Major and Trace Elements and Th Isotope Data, in Volcanism in the Campania Plain, Vesuvius, Campi Flegrei and Ignimbrites, Developments in Volcanology 9, B. De Vivo (ed.), Elsevier, New York, pgs. 249-288.

•Spera FJ and Bohrson WA, 2004, (INVITED), Open-System Magma Chamber Evolution: an Energy-Constrained Geochemical Model Incorporating the Effects of Concurrent Eruption, Recharge, Variable Assimilation and Fractional Crystallization (EC-E RAÇFC), Journal of Petrology 45:2459-2480.

•Fowler SJ, Bohrson WA, Spera FJ, 2004, Magmatic Evolution of the Skye Igneous Center, Western Scotland, Journal of Petrology 45: 2481-2505.

•Bohrson WA and Spera FJ, 2003, (INVITED), Energy-Constrained Open-System Magmatic Processes IV: Geochemical, Thermal and Mass Consequences of Energy-Constrained Recharge, Assimilation and Fractional Crystallization (EC-RAFC), Geochemistry, Geophysics, Geosystems (G3) 4: doi: 10.1029/2002GC00316.

•Spera FJ and Bohrson WA, 2002, (INVITED), Energy-Constrained Open-System Magmatic Processes III: Energy-Constrained Recharge, Assimilation and Fractional Crystallization (EC-RAFC), Geochemistry, Geophysics, Geosystems (G3) 3: doi:10.1029/2002GC00315.

•Davis AS, Clague DA, Bohrson WA, Dalrymple GB, and Greene HG, 2002, Seamounts at the Continental Margin of California: A Different Kind of Oceanic Intra-Plate Volcanism, Geological Society of America Bulletin 114: 316-333.

•De Vivo B, Rolandi G, Gans PB, Calvert A, Bohrson WA, Spera FJ and Belkin H, 2001, New constraints on the pyroclastic eruptive history of the Campanian volcanic Plain (Italy), Mineralogy and Petrology 73: 47-65

•Bohrson WA and Spera FJ, 2001, Energy-Constrained Open-System Magmatic Processes II: Application of Energy-Constrained Assimilation Fractional Crystallization (EC-AFC) Model to Magmatic Systems, Journal of Petrology 42: 1019-1041.

•Spera FJ and Bohrson WA, 2001, Energy-Constrained Open-System Magmatic Processes I: General Model and Energy-Constrained Assimilation and Fractional Crystallization (EC-AFC) Formulation, Journal of Petrology 42: 999-1018.



Teaching Interests and Schedule

Courses

Dr. Bohrson teaches undergraduate major course in Rocks and Minerals, as well as upper-level undergraduate/graduate level courses in Igneous Petrology, Volcanology, and Geochemistry. She also teaches graduate classes in her discipline and contributes to the core graduate classes, including research methods and field geology of the Pacfic Northwest.

Fall, 2011

  • Research Leave

Winter, 2012

  • GEOL 487
  • GEOL 504
  • GEOL 388 FIELD TRIP TO HAWAII

Spring, 2012