Geothermal Exploration of Mount Baker Hot Springs Through Ground-Based Magnetic and Gravity Surveys

The Washington State Division of Geology and Earth Resources (WDGER), together with the USGS, Altarock Energy Inc., Colorado College, Temple University, Innovate Geothermal Ltd., University of British Columbia, and Western Washington University(WWU), conducted phase two of a geothermal play fairway...

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Bibliographic Details
Main Authors: Schermerhorn, William D., Ritzinger, Brent, Anderson, Megan, Witter, Jeffrey, Glen, Jonathan, Forson, Corina, Stelling, Pete, Fournier, Dominique
Language:unknown
Published: 2022
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Online Access:http://www.osti.gov/servlets/purl/1839983
https://www.osti.gov/biblio/1839983
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Summary:The Washington State Division of Geology and Earth Resources (WDGER), together with the USGS, Altarock Energy Inc., Colorado College, Temple University, Innovate Geothermal Ltd., University of British Columbia, and Western Washington University(WWU), conducted phase two of a geothermal play fairway exploration at three plays (Mount Baker, Mount St. Helens seismic zone, and Wind River valley) along the Washington Cascade Range. The Mount Baker (MB) play is an ideal location for further investigation as a potential geothermal resource due to the presence of thermal features, young volcanic centers, existing geothermal leases, accessibility, and its proximity to existing transmission lines at the Baker Lake Dam. The goal of phase II exploration at all three plays is to collect geologic and geophysical data to help constrain spatial changes in subsurface lithology and structures that may be associated with the geothermal systems. Furthermore, this paper discusses the geothermal potential of the southeast flank of Mount Baker, WA by interpreting newly collected ground-based gravity and magnetic data. The Mount Baker play was surveyed from July-September, 2016 by the USGS, WDGER, and WWU. Results of a detailed magnetic and gravity surveys of the region surrounding the Baker hot springs, the primary surface expression of the hydrothermal system, are presented here. Gravity data were collected at 495 stations in the study area amounting to an area of roughly 150 square km. Approximately 93 km of line magnetometer data were collected within the study area, over a dozen magnetic susceptibility measurements were taken at 50 locations and about 50 hand samples were collected for density measurements. Preliminary data and modeling suggest pronounced magnetic anomalies trending NE/SW, generally in line with previously mapped lineaments identified in LiDAR. We present a series of preliminary two-dimensional forward models of the gravity and magnetic data as well as a 3D inversion model of magnetic susceptibility and interpret ...