| Title | Potential Hydrothermal Resource Areas and Their Reservoir Temperatures in the Eastern Snake River Plain, Idaho |
|---|---|
| Authors | Ghanashayam NEUPANE, Earl D. MATTSON, Cody J. CANNON, Trevor A. ATKINSON, Travis L. MCLING, Thomas R. WOOD, Wade C. WORTHING, Patrick F. DOBSON, and Mark E. CONRAD |
| Year | 2016 |
| Conference | Stanford Geothermal Workshop |
| Keywords | Eastern Snake River Plain, ESRP, RTEst, geothermal, geothermometer |
| Abstract | The Eastern Snake River Plain (ESRP) in southern Idaho is a region of high heat flow. Sustained volcanic activities in the wake of the passage of the Yellowstone Hotspot have turned this region into an area with great potential for geothermal resources as evidenced by numerous hot springs scattered along the margins of the plain and several hot-water producing wells and hot springs within the plain. Despite these thermal expressions, it is hypothesized that the pervasive presence of an overlying groundwater aquifer in the region effectively masks thermal signatures of deep-seated geothermal resources. The dilution of deeper thermal water and re-equilibration at lower temperature are significant challenges for the evaluation of potential resource areas in the ESRP. Over the past several years, we collected approximately 100 water samples from springs/wells for chemical analysis as well as assembled existing water chemistry data from the literature. We applied several geothermometric and geochemical modeling tools to these chemical compositions of ESRP water samples. Geothermometric calculations based on principles of multicomponent equilibrium geothermometry with inverse geochemical modeling capability (e.g., Reservoir Temperature Estimator, RTEst) have been useful for evaluating reservoir temperatures, and have indicated numerous potential moderate to high temperature geothermal prospects in the ESRP. Specifically, areas around southern/southwestern side of the Mount Bennett Hills and within the Camas Prairie in the western-northwestern regions of the ESRP and its margins suggest temperatures in the range of 140-200°C. In the northeastern portions of the ESRP, Lidy Hot Springs, Ashton, Newdale, and areas east of Idaho Falls have expected reservoir temperatures ≥140 °C. In the southern ERSP, areas near Buhl and Twin Falls are found to have temperatures as high as 160 °C. These areas are likely to host potentially economic geothermal resources; however, further detailed study is warranted at each site to evaluate hydrothermal suitability for economic use. |