Stress state and fluid-pressure level along the Whipple detachment fault, California

Research Article| September 01, 1994 Stress state and fluid-pressure level along the Whipple detachment fault, California Gary J. Axen; Gary J. Axen 1Departamento de Geología Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico Search for other works by this author on: GSW Google Scholar Jane Selverstone Jane Selverstone 2Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309-0250 Search for other works by this author on: GSW Google Scholar Geology (1994) 22 (9): 835–838. https://doi.org/10.1130/0091-7613(1994)022<0835:SSAFPL>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Gary J. Axen, Jane Selverstone; Stress state and fluid-pressure level along the Whipple detachment fault, California. Geology 1994;; 22 (9): 835–838. doi: https://doi.org/10.1130/0091-7613(1994)022<0835:SSAFPL>2.3.CO;2 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 SocietyGeology Search Advanced Search Abstract Brittle structures in the upper 200 m of the footwall of the Whipple detachment fault are used to characterize the state of stress under which the detachment slipped. They are younger than or coeval with chloride brecciation, and those that record shear typically are either moderately northeast-dipping normal structures or steep, northwest-striking, southwest-down structures that we interpret as conjugate shears. From this, we infer that the maximum principal stress was oriented 55°-80° from the detachment while they were active. The angle between the conjugate faults averages about 30°, indicating failure in the transtensional regime. During conjugate faulting the effective least principal stress was nearly equal to the tensile strength, the Whipple fault probably had a normal coefficient of static friction, and it slipped under hydrostatic to only moderately elevated fluid pressure. Rapid mineralization in the surroundings of major fault zones allows transtensional failure there and permits differential stress to be higher than if cohesionless friction limits strength. This causes resolved shear stress sufficient for slip on faults severely misoriented relative to the maximum principal stress. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.