Late Cenozoic structure and correlations to seismicity along the Olympic-Wallowa Lineament, northwest United States

Abstract

Research Article| July 01, 1993 Late Cenozoic structure and correlations to seismicity along the Olympic-Wallowa Lineament, northwest United States GARY M. MANN; GARY M. MANN 1U S. Geological Survey, M. S. 999, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar CHARLES E. MEYER CHARLES E. MEYER 1U S. Geological Survey, M. S. 999, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Author and Article Information GARY M. MANN 1U S. Geological Survey, M. S. 999, 345 Middlefield Road, Menlo Park, California 94025 CHARLES E. MEYER 1U S. Geological Survey, M. S. 999, 345 Middlefield Road, Menlo Park, California 94025 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1993) 105 (7): 853–871. https://doi.org/10.1130/0016-7606(1993)105<0853:LCSACT>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation GARY M. MANN, CHARLES E. MEYER; Late Cenozoic structure and correlations to seismicity along the Olympic-Wallowa Lineament, northwest United States. GSA Bulletin 1993;; 105 (7): 853–871. doi: https://doi.org/10.1130/0016-7606(1993)105<0853:LCSACT>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 SocietyGSA Bulletin Search Advanced Search Abstract Late Cenozoic fault geometry, structure, paleoseismicity, and patterns of recent seismicity at two seismic zones along the Olympic-Wallowa lineament (OWL) of western Idaho, northeast Oregon, and southeast Washington indicate limited right-oblique slip displacement along multiple northwest-striking faults that constitute the lineament. The southern end of the OWL originates in the Long Valley fault system and western Snake River Plain in western Idaho, where it accommodates basin-and-range extension. Several kilometers west of the Long Valley fault system, post-middle Miocene displacement along the OWL has resulted in adjacent areas of uplift and subsidence.The OWL in northeast Oregon consists of a wide zone of northwest-striking faults and is associated with several large, inferred, pull-apart basins. The OWL then emerges from the Blue Mountain uplift as a much narrower zone of faults in the Columbia Plateau known as the Wallula fault zone (WFZ). Structural relationships in the WFZ strongly suggest that it is a right-slip extensional duplex. An ash horizon that correlates with the Mount St. Helens "J" composition (10.7 Ka) is displaced vertically 5 m by a normal fault along a segment of the WFZ. The intensity center for a damaging M = 6.1 earthquake in 1936 is located in the WFZ only a few kilometers northeast of this Holocene fault. Other youthful-appearing, strike-slip and thrust faults are located farther northwest along the OWL and may pose a seismic hazard to adjacent population centers and critical facilities. 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.