Ph.D., University of California, Berkeley
Director of Undergraduate and Graduate Studies
Director of Environmental Science/Studies Program
GEOL 1305 - Oceanography
GEOL 3330 - Resources and the Environment
GEOL 5384 - Hydrogeology
GEOL 5386 - Geochemistry
GEOL 6370 - Aquatic and Mineral-Water Interface Geochemistry
John Walther's research efforts are geared to increase our understanding of mineral-solution interaction at the Earth's surface and in its crust, from both a theoretical and experimental standpoint. Under this umbrella a variety of projects concerning the composition and transport of fluids in groundwater, hydrothermal systems, and during metamorphism are proceeding.
He uses a unique large volume apparatus in the hydrothermal lab to measure mineral solubilities in H2O at the supercritical temperatures and pressures found in the crust. Walther also supervises research in the wet chemical lab to look at rates of reactions between minerals and solutions at near earth surface conditions and to characterize the adsorptive properties of mineral surfaces.
1986, Walther, J.V. and B.J. Wood (eds.), Fluid-Rock Interactions During Metamorphism, Adv. Phys. Geochem., 5, Springer-Verlag, New York, 211 pp.
2005, Walther, J.V., Essentials of Geochemistry, Jones and Bartlett Publishers, Boston, 704 pp.
2009, Walther, J.V., Essentials of Geochemistry, 2nd ed., Jones and Bartlett Publishers, Boston, 797 pp.
2013, Walther, J.V., Earth’s Natural Resources, Jones and Bartlett Publishers, Boston, 410 pp. in production
2001, Mukhopadhyay, B. and Walther, J.V., Acid-base chemistry of albite surfaces in aqueous solutions at surficial conditions, Chemical Geology, Chem Geology, v.174, p. 415-443.
2001, Walther, J.V., Experimental determination and analysis of the solubility of corundum in 0.1 and 0.5 m NaCl solutions between 400 and 600°C from 0.5 to 2.0 kbar, Geochim. Cosmochim. Acta, v. 65, p. 2843-2851.
2002, Walther, J.V., Experimental determination and analysis of the solubility of corundum in 0.1 molal CaCl2 solutions between 400 and 600°C at 0.6 to 2.0 kbar, Geochim. Cosmochim. Acta, v. 66, p. 1621-1625.
2003 Nour, M. H., Smith, E. H. and Walther, J.V., Spectroscopic evidence of silica-lignin complexes: implications for treatment of non-wood pulp wastewater, 7th International Water Association Symposium on Forest Industry Wastewaters, Seattle, WA, USA, June 1-4, 2003, PL-40, Proceedings (CD-ROM)
2004, Walther, J.V., Comment on: “Negative pressure of stretched liquid water. Geochemistry of soil capillaries,” by L. Mercury and Y. Tardy (2001) Geochim.Cosmochim. Acta, 65, 3391-3408 and “Thermodynamic properties of solutions in metastable systems under negative or positive pressures, by Mercury L., Azaroual M., Zeyen H., and Tardy Y. (2003): Geochim. Cosmochim. Acta, 67, 1769-1785. Geochim. Cosmochim. Acta, v. 68, 2771-2773.
2007, Walther, J.V., Comment: MAGic: A Phanerozoic model for the geochemical cycling of major rock-forming components: Amer. J. Sci.,. v. 307, p. 856-857.
2008, Walther, J.V., Comment: The thermodynamics and kinetics of microbial metabolism: Amer. J. Sci., v. 308, p. 1115-1116.
2011, Halder, S. and Walther, J.V., Far from equilibrium enstatite dissolution rates in alkaline solutions at earth surface conditions, Geochim. Cosmochim. Acta, v. 75. p. 7486-7493.