A direct comparison of resistivity models from helicopter transient electromagnetic and magnetotelluric datasets collected over a blind geothermal system in East Hawthorne, Nevada, USA.
Year: 2024
Type: report
Abstract: The thermal anomaly at Grover Point was first identified by gradient wells in the 1970's where a maximum measured temperature of 72.6°C at 88 meters depth was recorded.It was listed as part of a known geothermal area called Clan Alpine Ranch in the early 2000s and later characterized as associated with a fault step -over in the 2010s by the Nevada Bureau of M ines and Geology at University of Nevada Reno.In 2022, the DOE-funded BRIDGE project (Basin and Range Investigations for Developing Geothermal Energy) flew a network of airborne resistivity surveys over Dixie Valley, Nevada and other prospective areas in the Basin and Range.Shallow low-resistivity zones were identified in several profiles of this geothermal area, referred to as Grover Point in this study, that were consistent with geothermal clay alteration of poorly consolidated sediments over and adjacent to a previously unmapped northeast-striking, northwestdipping normal fault.Deeper low resistivity zones were also detected, but close to the limits of the method's depth of inves tigation.This inspired follow-up exploration activities including LiDAR analysis, a 2-meter temperature survey, geochemical sampling of nearby wells, analysis of existing airborne magnetic data, and the collection of a 110-station gravity survey.The preliminary results of this study further define the conceptual elements of a blind geothermal system through the BRIDGE project's research in exploration methodology and conceptual modeling.This workflow is being developed and applied by BRIDGE in the interest of providing the geothermal energy community with cost-effective exploration tools for efficient discovery of blind geothermal systems.
DOI: 10.2172/2584998
Authors: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States), Matthew Folsom, Geothermal Technologies Program, Steven Sewell, William Cumming, Jade Zimmerman, Andrew Sabin, Christine Downs, Nicholas Hinz, Carmen Winn, Paul Schwering
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Awards: G11630931, G413247060, G855168022
OpenAlex ID: W4413636452