GRC Transactions, Vol. 39, 2015 Preliminary Ranking of Geothermal Potential in the Cascade and Aleutian Volcanic Arcs, Part I: Data Collection Lisa Shevenell1, Mark Coolbaugh1,2, Nicholas H. Hinz2, Pete Stelling3, Glenn Melosh4, William Cumming5, and Corné Kreemer2 1ATLAS Geoscience, Inc., Reno NV, USA 2Nevada Bureau of Mines and Geology, UNR, Reno NV, USA 3Western Washington University, Bellingham WA, USA 4GEODE, Santa Rosa CA, USA • 5Cumming Geoscience, Santa Rosa CA, USA
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[email protected] Keywords Cascade, Aleutian, volcanic, geothermal, potential, structure, database ABSTRACT As part of a DOE funded project on Geothermal Play Fairway Analysis, a geothermal assessment of volcanic centers in the Cascade and Aleutian volcanic arcs is being conducted that includes a large data gathering effort dis- cussed in this paper, and a statistical modeling effort to qualitatively rank the geothermal potential of individual VCs in these two US arcs, discussed in a second companion paper. The data compiled from the Cascades and Aleutians are compared to geologic, geochemical and geophysical information from productive volcanic arc centers in the other parts of the world. Seven other volcanic arc segments from around the globe are used in this comparative study. Preliminary findings from data evaluation indicate that there are systematic changes in structural setting, from an extensional influ- ence south of Mt. Hood (in part due to encroachment of the back arc in the southern half) to more compressional north of Mt. Hood. Comparison with productive geothermal fields around the world shows that large fumarolic areas are associated with most >240°C power-producing geothermal systems outside the US arcs (e.g., Kamojang, Indonesia, among others), whereas there is a general absence of large fumarolic areas in the Cascades and Aleutian arcs, aside from of the Lassen volcano area.