Structural controls on geothermal circulation in Surprise Valley, California: A re-evaluation of the Lake City fault zone

Abstract

Research Article| March 01, 2014 Structural controls on geothermal circulation in Surprise Valley, California: A re-evaluation of the Lake City fault zone Anne E. Egger; Anne E. Egger † 1Geological Sciences, Central Washington University, 400 E. University Way, Ellensburg, Washington 98926-7418, USA †E-mail: eggera@cwu.edu Search for other works by this author on: GSW Google Scholar Jonathan M.G. Glen; Jonathan M.G. Glen 2U.S. Geological Survey, 345 Middlefield Road, MS989, Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar Darcy K. McPhee Darcy K. McPhee 2U.S. Geological Survey, 345 Middlefield Road, MS989, Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Anne E. Egger † 1Geological Sciences, Central Washington University, 400 E. University Way, Ellensburg, Washington 98926-7418, USA Jonathan M.G. Glen 2U.S. Geological Survey, 345 Middlefield Road, MS989, Menlo Park, California 94025, USA Darcy K. McPhee 2U.S. Geological Survey, 345 Middlefield Road, MS989, Menlo Park, California 94025, USA †E-mail: eggera@cwu.edu Publisher: Geological Society of America Received: 01 Sep 2012 Revision Received: 30 Aug 2013 Accepted: 17 Oct 2013 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2014 Geological Society of America GSA Bulletin (2014) 126 (3-4): 523–531. https://doi.org/10.1130/B30785.1 Article history Received: 01 Sep 2012 Revision Received: 30 Aug 2013 Accepted: 17 Oct 2013 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Anne E. Egger, Jonathan M.G. Glen, Darcy K. McPhee; Structural controls on geothermal circulation in Surprise Valley, California: A re-evaluation of the Lake City fault zone. GSA Bulletin 2014;; 126 (3-4): 523–531. doi: https://doi.org/10.1130/B30785.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Faults and fractures play an important role in the circulation of geothermal fluids in the crust, and the nature of that role varies according to structural setting and state of stress. As a result, detailed geologic and geophysical mapping that relates thermal springs to known structural features is essential to modeling geothermal systems. Published maps of Surprise Valley in northeastern California suggest that the “Lake City fault” or “Lake City fault zone” is a significant structural feature, cutting obliquely across the basin and connecting thermal springs across the valley. Newly acquired geophysical data (audio-magnetotelluric, gravity, and magnetic), combined with existing geochemical and geological data, suggest otherwise. We examine potential field profiles and resistivity models that cross the mapped Lake City fault zone. While there are numerous geophysical anomalies that suggest subsurface structures, they mostly do not coincide with the mapped traces of the Lake City fault zone, nor do they show a consistent signature in gravity, magnetics, or resistivities that would suggest a through-going fault that would promote connectivity through lateral fluid flow. Instead of a single, continuous fault, we propose the presence of a deformation zone associated with the growth of the range-front Surprise Valley fault. The implication for geothermal circulation is that this is a zone of enhanced porosity but lacks length-wise connectivity that could conduct fluids across the valley. Thermal fluid circulation is most likely controlled primarily by interactions between N-S–trending normal faults. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.