Assistant Visiting Professor
Office: Traphagen Hall 206A
Phone: (406) 994-6906
Office Hours: Spring 2013
MWF 12:30 - 1:30 pm
B.S. Geology, Tennessee Tech University, 2001
M.S. Geology, Southern Illinois University at Carbondale, 2006
Ph.D. Geology, University of Maryland at College Park, 2011
My doctoral research was directed at investigating two topics: liquid/liquid and liquid/solid phase relationships and redox equilibria in metal–oxide systems. These were experimental investigations with the primary focus of better understanding conditions of core formation in the Earth by constraining the high pressure behavior of the investigated systems. Experimental techniques included diamond anvil cells, multi anvil press, piston cylinder press, synchrotron x-ray diffraction, focused ion beam (sectioning diamond cell samples), and electron microprobe. More recently, I have conducted experiments directed at determining the temperature dependence of stable isotope fractionation at high pressures in metal-silicate systems as an additional constraint on core formation conditions in the Earth.
New areas of interest are:
- Hadean and Archean geology, in particular the relationship between very old metamorphic and igneous rocks and early Earth differentiation
- Deep mantle plumes, i.e. do they even exist, and if so then what relationship do they have to physical geological evidence available for examination; a related problem is how long in geologic history has plate tectonics operated
- The question of a layered mantle structure (e.g. is there mass transfer between the lower and upper mantles?), upper mantle heterogeneity and its relationship to variations in magma compositions as observed in the various basalt types.
Much of my previous geological work was in the general areas of surficial geology and hydrogeology. Prior to my most recent employment as an environmental geologist, I did a stint as a hydrogeologist with the Wetlands Geology Section of the Illinois State Geological Survey. My master's thesis work examined the Quaternary geology in southwest Illinois, where I investigated the glacial history of the Ames 7.5' Quadrangle. A geologic map based on my thesis research has been published in the Illinois Geologic Quadrangle (IGQ) Series. Before moving to southern Illinois, I spent a fair amount of time wandering around in Tennessee and looking at karst hydrogeology, contaminant transport, and geomorphology.
Shofner, G.A., Campbell, A.J., Righter, K., Danielson, L.R., and Rahman, Z. High pressure and temperature metal–silicate partitioning of W and constraints on core formation conditions in the Earth. Manuscript in preparation.
Shofner, G.A., Campbell, A.J., Righter, K., Danielson, L.R., Fischer, R.A., and Deane, J. The W–WO2, Co–CoO, and Cr–Cr2O3 oxygen buffers at high pressures and temperatures, with application to metal–silicate partitioning. Manuscript in preparation.
Shofner, G.A. (2011) High pressure redox geochemistry of tungsten in metal–silicate systems: implications for core formation in the Earth. Dissertation (Ph.D.), University of Maryland, Col-lege Park, 175p.
Fischer R. A., Campbell A. J., Lord O. T., Shofner G. A., Dera P., and Prakapenka V. B. (2011) Phase transition and metallization of FeO at high pressures and temperatures. Geophys. Res. Lett., 38, L24301.
Fischer, R.A., Campbell, A.J., Shofner, G.A., Lord, O.T., Dera, P., and Prakapenka, V.B. (2011) Equation of state and phase diagram of FeO. Earth Planet. Sci. Lett., 304, 496-502.
Grimley, D.A. and Shofner G.A. (2008) Surficial Geology of Ames Quadrangle, Monroe and Randolph Counties, Illinois. Illinois State Geological Survey Illinois Geologic Quadrangle Map, IGQ Ames-SG, 2 sheets, 1:24,000.
Pociask, G.E. and Shofner, G.A. (2007) Level II hydrogeologic characterization report, Sugar Camp Creek potential wetland compensation site. Illinois State Geological Survey Open File Series 2007-2, 57 p.
Shofner, G.A. (2006) The Quaternary geology of the Ames 7.5 minute quadrangle, Monroe and Randolph counties, Illinois. Thesis (M.S.), Southern Illinois University at Carbondale, 3 map sheets, 156 p.
Shofner, G.A., Hart-Carstens, K., and Carr, K.W. (2005) Level II hydrogeologic characterization report, Edgewood and Larkinsburg potential wetland compensation sites. Illinois State Geological Survey Open File Series 2005-10, 38 p.
Bradshaw, D., Bynum, K., Cohoe-Griego, S., Dillehay, G., Hillis, E., McCarty, K., Lynn, J., and Shofner, G. (2001) Following the water in the Falling Water River. Proceedings from The Eleventh Annual Tennessee Water Resources Symposium, v. 11, p. P-2 - P-5.
Shofner, G.A., Mills, H.H., and Duke, J.E. (2001) A simple map index of karstification and its relationship to sinkhole and cave distribution in Tennessee. Journal of Cave and Karst Studies, v. 63, n. 2, p. 67-75.
Shofner, G.A., Campbell, A.J., Danielson, L.R., Righter, K., and Rahman, Z. (2010) Met-al/silicate partitioning of tungsten at high pressures and temperatures. Fall AGU Meeting, Ab-stract V44B-05.
Shofner, G.A., Danielson, L., Righter, K., and Campbell, A.J. (2010) High pressure/temperature metal silicate partitioning of tungsten. 41st Lunar and Planetary Science Conference, Abstract 2612.
Shofner, G.A., Campbell, A.J., Danielson, L. and Righter, K. (2009) Synchrotron x-ray diffrac-tion studies of metal-oxide pairs. COMPRES Annual Meeting, Bretton Woods, NH.