My major research focus concerns magma production and evolution at subduction zones and the surface volcanism that results. My pet subduction zone is the Central American subduction zone which exhibits some of most diverse and abundant volcanic activity on Earth.
Walker, J.A., Teipel, A.P., Ryan, J.G. and Syracuse, E., 2009, Light elements and Li isotopes across the northern portion of the Central American subduction zone: Geochemistry, Geophysics and Geosystems, v. 10, Q06S16, doi:10.1029/2009GC002414.
Walker, J.A., Mickelson, J.E., Thomas, R.B., Patino, L.C., Cameron, B.I., Carr, M.J., Feigenson, M.D. and Edwards R.L., 2007, U-series disequilibria in Guatemalan lavas, crustal contamination and implications for magma genesis along the Central American subduction zone: Journal of Geophysical Research, V. 112, B06205, doi:10.1029/2006JB004589.
de Leeuw, G.A.M., Hilton, D.R., Fischer, T.P. and Walker J.A., 2007, The He-CO2 isotope and relative abundance characteristics of geothermal fluids in El Salvador and Honduras: new constraints on volatile mass balance of the Central American volcanic arc: Earth and Planetary Science Letters, v. 258, p. 132-146.
Elkins, L.J., Fischer, T.P., Hilton, D.R., Sharp, Z.D., McKnight, S. and Walker, J., 2006, Tracing nitrogen in volcanic and geothermal volatiles from the Nicaraguan volcanic front: Geochimica et Cosmochimica Acta, v. 70, p. 5215-5235.
Cameron, B.I. and Walker, J.A., 2006, Diverse volcanism in southeastern Guatemala: the role of crustal contamination: in Rose, W.I., Bluth, G.J.S., Carr, M.J., Ewert, J.W., Patino, L.C. and Vallance, J.W., eds., Volcanic Hazards in Central America: Geological Society of America Special Paper 412, p. 121-139.
Walker, J.A., Templeton, S. and Cameron, B.I., 2006, The chemistry of spring waters and fumarolic gases encircling Santa María volcano, Guatemala: insights into regional hydrothermal activity and implications for volcano monitoring: in Rose, W.I., Bluth, G.J.S., Carr, M.J., Ewert, J.W., Patino, L.C. and Vallance, J.W., eds., Volcanic Hazards in Central America: Geological Society of America Special Paper 412, p. 59-83.

Professor
Igneous Petrology/Geochemistry, Volcanology
815-753-7936
E-mail: jwalker@niu.edu
412A Davis Hall
Ph.D., Rutgers University, 1982
M.S., Rutgers University, 1980 B.S., Upsala College, 1975
815-753-1943
815-753-1945 (fax)
askeae@niu.edu