Research Interests - Trace element and isotope geochemistry
. (Funding sources include National Science Foundation, U.S. Geological Survey and private industry) My students and I have studied the geochemistry & origins of massif-type anorthosites, cumulate processes associated with Platinum Group Element deposits of the Stillwater Complex, granites spatially & temporally associated with U mineralization, and mass balance relationships in assimilation-fractional crystallization processes & their implications for the development of the continental crust. A recent addition to this research area is the geochemistry & sourcing of obsidian artifacts.
. (Funding by Petroleum Research Fund of the American Chemical Society) My students and I have studied the distribution and isotopic compositions of the inorganic constituents N 2 , CO 2 , He and Ar in anomalous natural gases of eastern Colorado . Limiting, steady-state diffusion calculations indicate rapid leakage of these gases, and by analogy CH 4 , through reservoir caprocks; natural gas reservoirs are a highly dynamic system with ongoing depletion and replenishment. Isotopic compositions of these inorganic constituents require a multiplicity of sources, including thermal breakdown of organic material within the sedimentary column, breakdown and degassing of silicates within the crystalline basement, and a small, but clearly identifiable "mantle" component. Clearly, natural gas reserves represent complex mixtures of constituents from a variety of sources.
(Funding provided by the Colorado Advanced Materials Institute, and the Colorado State Historical Society) The chemical compositions of lithic materials used as raw materials by Pre-Columbian native Americans can be used to identify localities where the material originated. This information is essential to locating and tracing ancient trade and migrations routes. Currently active projects include analysis of obsidian debitage material from Nicaragua , and a feasibility study of petrified wood within the state of Colorado .
Selected Publications ( * indicates Geochemistry PhD student research)
Recent Presentations Related to Archaeomaterials Research
E.C. Simmons, K.L. Aggen , M.E. Eberhart, and F.J. Fraikor, “Preliminary Sourcing of Obsidian Debitage Associated with Evidence for Metallurgical Activity in Managua , Nicaragua ,” Proceedings of the 55 th Annual Meeting , Geological Society of America , Rocky Mountain Chapter, Ft. Lewis, College, CO, May 7-9, 2003.
T. Casias, H. Kleebe, F.J. Fraikor and E.C. Simmons, “Electron Microscopy Analysis of Petrified Wood Samples,” Proceedings of the 55 th Annual Meeting , Geological Society of America , Rocky Mountain Chapter, Ft. Lewis, College, CO, May 7-9, 2003.
F.J. Fraikor, T. Casias, E.C. Simmons and S. Kalasz, “ Scanning Electron Microscopy of Petrified Wood Archaeological Artifacts”, First Prize, Category 5, International Metallographic Contest, The VII InterAmerican Congress on Electron Microscopy , San Antonio, Tx, Aug. 3-7, 2003.
K. Black, S. Kalasz, F.J. Fraikor and E.C. Simmons, “The Colorado Petrified Wood Sourcing Project,” 6 th Biennial Meeting of the Rocky Mountain Anthropological Conference, Estes Park, CO, Sept. 20, 2003.
S. Kalasz, K. Black, F.J. Fraikor and E.C. Simmons, “CCPA Petrified Wood Project Sourcing Proogress Report,” 2004 CCPA Conference, UCCS, Colorado Springs, CO, March 26, 2004 .
: Introduction to Geochemistry, Isotope Geochemistry, Geochemistry of Igneous Rocks.
: Thermodynamics, Chemical Thermodynamics for Geologists, Introductory Chemistry.