Conceptual Subsurface Model of the Blackfoot Volcanic Field, Southeast Idaho: A Potential Hidden Geothermal Resource

Abstract

Development of a conceptual model for the Blackfoot Volcanic field in southeast Idaho seeks to understand mechanisms and pathways for heat transfer and loss. This potential hidden geothermal resource is a young bimodal, volcanic rift system consisting of features similar to the Coso geothermal field. However the Blackfoot Volcanic field lacks significant geothermal surficial features, alteration and has relatively low temperatures at depths inconsistent with young 58 ka (Heumann, 2004) felsic volcanism. Development of a conceptual model has generated several hypotheses regarding explanations of heat transfer and loss. These hypotheses include isothermal drawdown; heat transfer and loss pathways along faults; and the intersection of two major thrusts at depths similar to the estimated depthof the rhyolitic magma chamber.