Exploring for fault-hosted geothermal systems using low temperature thermochronology and thermo-kinematic modeling
Geothermal energy serves a critical role in the transition to a carbon-free energy future. A major uncertainty when exploring for naturally occurring geothermal systems is whether an active fault mapped at the surface is permeable at depth and is acting as an upwards pathway for hydrothermal fluids. Tools that can assess the fluid flow history and the present behavior of faults prior to drilling are therefore critical to reducing risk and accelerating geothermal development. Funded by the TomKat Center for Sustainable Energy at Stanford University and Zanskar Geothermal and Minerals Inc.
High-resolution thermochronology from rocks within and increasingly distant from the surface trace of major faults is a promising means for constraining recent hydrothermal activity. Low temperature thermochronometers such as the Helium system in the mineral apatite are sensitive to even short-lived thermal disturbances and thus offer the potential to quantify transient hydrothermal events along a fault system. Rapid and affordable low temperature thermochronology is now possible thanks to dramatically declining costs in mass spectrometry and improved computational modeling, making it a novel and cost effective tool for geothermal exploration. The proposed study seeks to demonstrate these methods in assessing the geothermal potential of an active regional fault system in western Alaska, the Kigluaik normal fault system, just north of Nome near the Pilgrim Hot Springs. Combined with 3D geologic modeling, the results are anticipated to add to our understanding of fault controlled geothermal systems and help test whether this previously unexplored type of system exists within the Central Hot Springs Belt of Alaska.
As a power source whose efficiencies are increased in colder climates, geothermal offers an important means to decarbonizing Arctic societies where high latitude and extreme climates make solar, wind, hydro, and battery sources of energy significantly less cost-effective. Arctic communities such as a town the size of Nome, spend ~ $8M/year on diesel generated electricity.
Funded by the TomKat Center for Sustainable Energy at Stanford University and Zanskar Geothermal and Minerals Inc. Our innovation team includes Elizabeth Miller, Dr. Carl Hoiland of Zanskar and Jason Craig, Ph.D. student, Stanford (MS in geothermal exploration, UNR).
View our proposal TomKat Research Grant (pdf)
View our illustrated explanatory poster Poster TomKat Alaska Project (pdf)
View our previously published NSF-funded geologic map of the Kigluaik Mts, AK Geologic Map of the Kigluaik Mts (Amato and Miller, 2004) (pdf)
Publications
Amato, J. A., and E. L. Miller. 1998. “Bedrock Geologic Map of the Kigluaik Mountains, Seward Peninsula, Alaska,” Division of Geological and Geophysical Surveys, Public Data File 97-31,
Miller, Elizabeth. 2017. “Circum-Arctic Lithosphere Evolution (CALE) Transect C: Displacement of the Arctic Alaska–Chukotka Microplate towards the Pacific during Opening of the Amerasia Basin of the Arctic.” Geological Society London Special Publication: Circum Arctic Lithosphere Evolution. DOI: 10.1144/SP460.9
Dumitru, T. A., E. L. Miller, P. B. OSULLIVAN, J. M. Amato, K. A. Hannula, et al. 1995. “CRETACEOUS TO RECENT EXTENSION IN THE BERING STRAIT REGION, ALASKA.” TECTONICS 14 (3). AMER GEOPHYSICAL UNION: 549–63.
Klemperer, S., A Grantz, E. Miller, D. Scholl, and the Bering-Chukchi Working Group. 2002. “Crustal Structure of the Bering and Chukchi Shelves: Deep Seismic Reflection Profiles across the North American Continent between Alaska and Russia.” Geological Society of America Special Paper 360,
Akinin, Vycheslav V., Elizabeth L. Miller, Jaime Toro, Andrey Prokopiev, Eric S. Gottlieb, et al. 2020. “Episodicity and the Dance of Late Mesozoic Magmatism and Deformation along the Northern Circum-Pacific Margin: North-Eastern Russia to the Cordillera.” EARTH-SCIENCE REVIEWS 208. ELSEVIER. DOI: 10.1016/j.earscirev.2020.103272
Amato, J. M., E. L. Miller, D. Whitney, C. Teyssier, and C. S. Siddoway. 2004. Geologic Map and Summary of the Evolution of the Kigluaik Mountains Gneiss Dome, Seward Peninsula, Alaska. Edited by D. Whitney, C. Teyssier, and C. S. Siddoway. Gneiss Domes in Orogeny. Geological Society of America Special Paper. Geological Society of America.
Amato, J. M., J. E. Wright, P. B. Gans, and E. L. Miller. 1994. “MAGMATICALLY INDUCED METAMORPHISM AND DEFORMATION IN THE KIGLUAIK GNEISS DOME, SEWARD PENINSULA, ALASKA.” TECTONICS 13 (3). AMER GEOPHYSICAL UNION: 515–27.
Amato, J., and E. L. Miller. 2002. “Orogenic Mass Transfer and Orthogonal Flow Directions in Extending Continental Crust: An Example from the Cretaceous Kigluaik Gneiss Dome, Seward Peninsula, Alaska,” Geological Society of America Special Paper 360,
Miller, E. L., A. T. Calvert, and T. A. Little. 1992. “STRAIN-COLLAPSED METAMORPHIC ISOGRADS IN A SILLIMANITE GNEISS DOME, SEWARD PENINSULA, ALASKA.” GEOLOGY 20 (6). GEOLOGICAL SOC AMERICA: 487–90.
Hannula, K. A., E. L. Miller, T. A. Dumitru, J. Lee, and C. M. Rubin. 1995. “STRUCTURAL AND METAMORPHIC RELATIONS IN THE SOUTHWEST SEWARD PENINSULA, ALASKA - CRUSTAL EXTENSION AND THE UNROOFING OF BLUESCHISTS.” GEOLOGICAL SOCIETY OF AMERICA BULLETIN 107 (5). GEOLOGICAL SOC AMER, INC: 536–53.
Miller, E.L., A. Grantz, and S. Klemperer. 2002. “Tectonic Evolution of the Bering Shelf-Chukchi Sea-Arctic Margin and Adjacent Landmasses.” Geological Society of America Special Paper 360.