Mitchell Bennett


Mitchell Bennett is a Geologist at the U.S. Geological Survey in Denver, CO. He assists with melt and fluid inclusion petrography and analysis in the Denver Inclusion Analysis Laboratory ( At present he aids in the study of ore-forming hydrothermal fluids encountered in the Yellow Pine Au-Sb-W deposit in Idaho and in IOA-IOCG deposits in SE Missouri. In addition, he runs and maintains the USGS Experimental Petrology Lab's cold-seal pressure vessels used in high temperature melt and fluid inclusion experiments.

Prior to joining the USGS, Mitchell worked as an intern at the National Renewable Energy Laboratory (NREL) within the Technology Systems and Sustainability Analysis Group in Golden, CO, where he provided research support during development of NREL’s Open Energy Information (OpenEI) website. As a part of this work he prepared case study reports on active and producing geothermal resource areas and worked with a team of geologists and developers to construct a comprehensive database of geothermal exploration efforts used to define different geothermal prospects throughout the United States.

During his M.Sc. research he used fluid inclusion and cathodoluminescence petrography to study multi-stage vein quartz from a range of different porphyry deposit classes, including those at Far Southeast in the Philippines, Butte in Montana, Bingham Canyon in Utah, and in the Maricunga Belt in Chile. He examined how these characteristics relate to vein-scale processes associated with ore mineral deposition and emplacement depth within the larger context of the parent hydrothermal systems. Based on these investigations he developed new laboratory preparation and analytical procedures that utilize simple petrographic techniques to identify transported porphyry quartz grains in fluvial sands, to be implemented in conjunction with routine geochemical surveys as a new exploration technique for porphyry deposits. His areas of expertise include: fluid inclusion petrography and microthermometry, cathodoluminescence petrography, melt inclusion analysis, ore deposits, and geothermal systems.



Monecke, T., Monecke, J., Reynolds, T.J., Tsuruoka, S., Bennett, M., Skewes, W., and Palin, R., 2018. Quartz Solubility in the H2O-NaCl System: A Framework for Understanding Vein Formation in Porphyry Copper Deposits: Economic Geology, v. 113, no. 5, p. 1007–1046, doi: 10.5382/econgeo.2018.4580. [Link]

Young, K.R., Witherbee, K., Levine, A., Keller, A., Balu, J., and Bennett, M., 2014. Geothermal Permitting and NEPA Timelines: Geothermal Resources Council Transactions, GRC Annual Meeting 2014, Portland, Oregon. [Link]

Young, K.R., Bennett, M., and Atkins, D., 2014. Geothermal Exploration Case Studies on OpenEI: Proceedings, Thirty-Ninth Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California, SGP–TR–202. [Link]

Bennett, M., 2014. Cathodoluminescence and Fluid Inclusion Characteristics of Hydrothermal Quartz from Porphyry Deposits: M.Sc. Thesis, Colorado School of Mines, 157 p. [Link]

Zhao, Xin-Fu, Zhou, Mei-Fu, Hitzman, M.W., Li, Jian-Wei, Bennett, M., Meighan, C., and Anderson, E., 2012. Late Paleoproterozoic to Early Mesoproterozoic Tangdan Sedimentary Rock-Hosted Strata-bound Copper Deposit, Yunnan Province, Southwest China: Economic Geology, v. 107, p. 357-375. [Link]

Easley, E., Garchar, L., Bennett, M., Morgan, P., and Wendlandt, R., 2011. A Geochemical and Isotopic Study of Two Geothermal Resources In the Rio Grande Rift, Colorado and New Mexico: The Mountain Geologist, v. 48, no. 4, p. 95-106. [Link]

Bennett, M., Monecke, T., Reynolds, J., Kelly, N., Lowers, H., Gӧtze, J., and Arribas, A., In Review. Hydrothermal Alteration of Quartz and Inheritance of Fluid Inclusion Assemblages: A Case Study on Vein Quartz from the Far Southeast Porphyry Cu-Au Deposit, Philippines: Economic Geology.