Structure of central part of Sawtooth Range, Montana

Abstract

Research Article| August 01, 1943 Structure of central part of Sawtooth Range, Montana CHARLES DEISS CHARLES DEISS Search for other works by this author on: GSW Google Scholar GSA Bulletin (1943) 54 (8): 1123–1168. https://doi.org/10.1130/GSAB-54-1123 Article history received: 04 Jan 1943 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation CHARLES DEISS; Structure of central part of Sawtooth Range, Montana. GSA Bulletin 1943;; 54 (8): 1123–1168. doi: https://doi.org/10.1130/GSAB-54-1123 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 The Sawtooth Range is south of Glacier National Park and forms 85 miles of the Rocky Mountain front in northwestern Montana. The range averages 9 miles in width, consists of a broad northeastward-pointing arc, and extends north across the Saypo quadrangle.The sedimentary rocks exposed in the Sawtooth Range are approximately 5500 feet thick, are Paleozoic and Mesozoic in age, and are divided into nine formations: Pagoda and Steamboat (Middle Cambrian), Switchback (Middle and Upper Cambrian), and Devils Glen (Upper Cambrian), unnamed formation (Upper Devonian), Hannan (Mississippian), Ellis (Upper Jurassic), and Kootenai and Colorado (Lower and Upper Cretaceous).Three structural provinces occur in the central part of the Range: an eastern province, characterized by westward-dipping high-angle to moderately low-angle thrusts that increase in number northward; a central province, characterized by closely spaced, westward-dipping, high-angle thrusts, and by drag-folding of the Devonian and Mississippian rocks comprising the imbricated slices; and a western province, characterized by folded, low-angle overthrusts, above which the rocks are compressed into large open folds.The structures were produced by stresses from the west during the Laramide orogeny. The mountains were maturely eroded during the Tertiary, when the east-west courses of the main streams were established. Uplift in the Pliocene? raised the range to its present altitude but did not cause additional deformation. 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.