Frank Spear

Department Head and Professor, Earth and Environmental Sciences

My research group is focused in two major directions in metamorphic geochemistry.

Studies of crustal evolution:A major focus of my research group over the past three decades has been on the development of new techniques for the interpretation of metamorphic petrogenesis. These studies involve modeling mineral reactions, textures, and chemical zonation in both major and accessory phases. The goal of this work is to construct pressure-temperature-deformation-time histories that can be used to interpret the tectonic evolution of a terrane. We have applied these techniques to areas in the Alps, New England, southern Chile, the Mojave desert, British Columbia, the Adirondacks of New York, and the Cyclades Blueschist Belt of Greece. Current field projects are underway in Central New England The Ruby-Humboldt range of eastern Nevada Adirondack Mountains of New York Cyclades Blueschist Belt, Greece 

MetPetDB: A database for metamorphic geochemistry. The field of metamorphic petrology involves the collection of large amounts of data including sample characterization, field and thin section descriptions, photomicrographs of phase assemblages and reaction textures, SEM (backscatter secondary electron images of thin sections, X-ray maps depicting the distribution and zoning of elements in phases, cathodoluminescence images of phases such as zircon or quartz to reveal trace element zoning, as well as analyses of whole-rock and mineral chemistry and isotope abundances. Managing such large quantities of data is a large effort and preserving these data for the future is not yet routine except for the small amounts that see their way into publication. MetPetDB (Metamorphic Petrology Database) is an NSF-funded project involving collaboration between metamorphic petrologists and computer scientists at Rensselaer Polytechnic Institute with an international working group. The goal is the development of an informatics system that will prove to be a valuable resource for both the preservation of valuable data as well as serving as a platform for new, innovative research directions. The database can be accessed here: http://MetPetDB.rpi.edu and a summary of published articles currently uploaded into the database may be examined here: http://metpetdb.rpi.edu/MetPetRest/parse_publications.html

Education

Ph.D., 1976 University of California, Los Angeles B.A., 1971 Amherst College, Amherst MA.

Select Works
  • Spear, F.S. (1993) Metamorphic Phase Equilibria and Pressure-Temperature-Time Paths, 799 p. Mineralogical Society of America, Washington, D. C.
  • Spear, F.S., Wolfe, O.M. (2022) Nucleation theory applied to the development of contrasting garnet crystal densities. Contributions to Mineralogy and Petrology 177, 14p.
  • Wolfe, O.M., Spear, F.S., Harrison, T.M. (2021) Pronounced and rapid exhumation of the Connecticut Valley Trough revealed through quartz in garnet Raman barometry and diffusion modeling of garnet dissolution-reprecipitation reactions. Journal of Metamorphic Geology, 39, 1045-1069.
  • Spear, F.S., Wolfe, O.M. (2020) Revaluation of "equilibrium" P-T paths from zoned garnet in light of quartz inclusion in garnet (QuiG) barometry. Lithos, 372: 10.
  • Wolfe, O.M., Spear, F.S. (2020) Regional quartz inclusion barometry and comparison with conventional thermobarometry and intersecting isopleths from the Connecticut Valley trough, Vermont and Massachusetts, USA. Journal of Petrology.
  • Spear, F. S., and Wolfe, O. M. (2019) Implications of overstepping of garnet nucleation for geothermometry, geobarometry and P–T path calculations: Chemical Geology, v. 530, 11 pp.
  • Kohn, M. J., Castro, A.E., Kerswell, B., Ranero, C.R., and Spear, F.S. (2018) Shear heating reconciles thermal models with the metamorphic rock record of subduction. Proceedings of the National Academy of Sciences.
  • Wolfe, O. M. and Spear, F. S. (2018) Determining the amount of overstepping required to nucleate garnet during Barrovian regional metamorphism, Connecticut Valley Synclinorium. Journal of Metamorphic Geology, 36, 79-94.