Webster, James main content.

James Webster

A man, James Webster, on small boat wearing a windbreaker and life preserver jacket. Water and hills in background.

Curator Emeritus, Department of Earth and Planetary Sciences, Division of Physical Sciences
Professor Emeritus, Richard Gilder Graduate School

In Memoriam

Education

  • Arizona State University, Ph.D, 1987
  • Colorado School of Mines, M.S., 1980
  • North Carolina State University, B.S., 1978

Research Interests

Dr. Webster investigates how the volatiles water, fluorine, chlorine, sulfur, and carbon dioxide influence how magmas evolve chemically; how they control the formation of metallic ore deposits; and how they impact volcanic eruptions. He investigates how ore deposits are generated through late-stage hydrothermal and mineralizing processes in magmas.  Dr. Webster also studies the influence of volatiles on the melting behavior and stability of minerals, and how and when magmatic-hydrothermal fluids are released from magma. This research involves study of silicate melt inclusions, which are microscopic inclusions of silicate melt trapped in minerals from mineralizing and/or erupting magmas. To assist in this research, he has recently constructed a Vernadsky-style heating stage for observing silicate melt inclusions, with a microscope, while they are melted at high temperatures.  He is presently working on hydrothermal experiments involving apatite, silicate melts, and volatile-rich fluids to better understand magmatic processes. With scientists from the University of Hannover, Germany, he is developing a model to compute Cl solubilities in silicate melts.  Other research – with museum colleagues – on sulfur, chlorine, carbon dioxide, and water provides information on the nature of gases released during explosive volcanism at Augustine volcano, Alaska, and Dr. Webster has recently begun a new study on sapphire- and spinel-bearing metamorphic rocks of the Mogok region of Myanmar. 

Publications

  • Goldoff, B., Webster, J.D., Harlov, D. (2012) Characterization of fluor-chlorapatites by electron probe microanalysis with a focus on time-dependent intensity variation of halogens.  American Mineralogist 97, 1103-1115.
  • Webster, J.D., Botcharnikov, R.E. (2011) Distribution of sulfur between melt and fluid in S-O-H-C-Cl-bearing magmatic systems at shallow crustal pressures and temperatures. In: H. Behrens and J.D. Webster, eds., Sulfur in Magmas and Melts and its Importance for Natural and Technical Processes, Reviews in Mineralogy and Geochemistry 74, 247-283.
  • Di Martino, C., Forni, F., Frezzotti, M.L., Palmeri, R., Webster, J.D., Ayuso, R., Lucchi, F., Tranne, C.A. (2010) Formation of cordierite-bearing lavas during anatexis in the lower crust of Lipari (Aeolian Islands, Italy). Contributions to Mineralogy and Petrology, DOI:http://www.springerlink.com/content/0010- 7999/?k=beryllium&Article+Category=Original+Paper&o=10.
  • Thomas, R., Webster, J.D., and Davidson, P. (2010) Be daughter minerals in fluid and melt inclusions – Implications for the enrichment of Be in granite-pegmatite systems. Contributions to Mineralogy and Petrology 161, 483-495.
  • Webster, J.D., Mandeville, C.W., Goldoff, B., Coombs, M.L., Tappen, C. (2010) Augustine volcano, Alaska: The influence of volatile components in magmas erupted AD 2006 to 2100 years before present.  In: J. Power, M.L. Coombs, J. Freymueller, eds., The 2006 Eruption of Augustine Volcano, U.S. Geol. Surv. Prof. Paper 1769, 383-423.

Teaching Experience

Faculty Appointments

  • Co-PI and Co-Manager of AMNH Physical Sciences REU Program
  • AMNH Masters of Arts in Teaching Program

Courses Taught

  • Fluids in the Earth, University of Naples, Italy

Graduate Advisees

  • Alexander Iveson, Washington State University-Pullman
  • Angela Doherty, University of Messina, Italy

Graduate Committees

  • Alexander Lloyd, LDEO, Columbia University