Structural development of an accretionary prism by thrust and strike-slip faulting: Shumagin region, Aleutian Trench

Abstract

Research Article| May 01, 1988 Structural development of an accretionary prism by thrust and strike-slip faulting: Shumagin region, Aleutian Trench STEPHEN D. LEWIS; STEPHEN D. LEWIS 1Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 Search for other works by this author on: GSW Google Scholar JOHN W. LADD; JOHN W. LADD 1Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 Search for other works by this author on: GSW Google Scholar TERRY R. BRUNS TERRY R. BRUNS 2U.S Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1988) 100 (5): 767–782. https://doi.org/10.1130/0016-7606(1988)100<0767:SDOAAP>2.3.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation STEPHEN D. LEWIS, JOHN W. LADD, TERRY R. BRUNS; Structural development of an accretionary prism by thrust and strike-slip faulting: Shumagin region, Aleutian Trench. GSA Bulletin 1988;; 100 (5): 767–782. doi: https://doi.org/10.1130/0016-7606(1988)100<0767:SDOAAP>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 A combination of SEABEAM swath bathymetric data, closely spaced single-channel seismic reflection profiles, and multichannel seismic reflection profiles from the Shumagin Islands region indicates that the large-scale deformation of the accretionary prism in this segment of the Aleutian Trench occurs progressively through several stages: (1) folding along axes perpendicular to the plate-convergence direction in the region, (2) thrust faulting in the direction of plate convergence and (3) oblique strike-slip faulting along conjugate west-northwest-trending right-lateral and north-northeast-trending left-lateral faults. Strike-slip faults occur in distinct domains, with right-lateral oblique faults present west of a major transverse fault at long 161°W. and left-lateral oblique faults prevalent east of 161°W.The structural development of the modern Aleutian Trench fore arc in this region is probably affected by pre-Eocene inherited structures that are still active in the present-day stress regime. A major domain boundary fault located at long 161°W. is probably part of a strike-slip fault system that also bounds Sanak Basin farther landward on the Shumagin shelf. This fault zone is nearly coincident with the mapped position of the western edge of the Shumagin seismic gap. These transverse structures in the Shumagin fore arc probably influence the spatial distribution of stress buildup related to subduction, and hence the locations of rupture zones of great interplate earthquakes, along this segment of the Aleutian Trench. 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.