Displacement of the Lewis thrust sheet in southwestern Canada: New evidence from seismic reflection data

Abstract

Research Article| September 01, 1994 Displacement of the Lewis thrust sheet in southwestern Canada: New evidence from seismic reflection data Arie J. van der Velden; Arie J. van der Velden 1Department of Geology and Geophysics, University of Calgary, Calgary, Alberta T2N 1N4, Canada Search for other works by this author on: GSW Google Scholar Frederick A. Cook Frederick A. Cook 1Department of Geology and Geophysics, University of Calgary, Calgary, Alberta T2N 1N4, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Arie J. van der Velden 1Department of Geology and Geophysics, University of Calgary, Calgary, Alberta T2N 1N4, Canada Frederick A. Cook 1Department of Geology and Geophysics, University of Calgary, Calgary, Alberta T2N 1N4, Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1994) 22 (9): 819–822. https://doi.org/10.1130/0091-7613(1994)022<0819:DOTLTS>2.3.CO;2 Article history First Online: 02 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 Arie J. van der Velden, Frederick A. Cook; Displacement of the Lewis thrust sheet in southwestern Canada: New evidence from seismic reflection data. Geology 1994;; 22 (9): 819–822. doi: https://doi.org/10.1130/0091-7613(1994)022<0819:DOTLTS>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 Seismic reflection data across the Rocky Mountain trench in the southern Canadian Cordillera reveal prominent reflections from Mesoproterozoic (Aldridge Formation) sills that allow a direct stratigraphic correlation across the trench when 10 km of extension is restored. Trun cated reflections at ∼11-15 km depth on the west side of the trench are interpreted as a footwall cutoff of the Lewis thrust in Belt-Purcell strata that lies ∼115 km west of the leading edge of the Lewis thrust, exposed in the Waterton area; retrodeformation of the Lewis sheet requires a minimum of 75 km of transport on the Lewis thrust and 40 km of transport by the development of footwall-domain duplexes. The trench is located above a major change in slope of the top of the North American basement that coincides with a pronounced increase in thickness of lower Belt-Purcell strata in their retrodeformed position. This transition may represent part of an ancient margin that was initially established in Paleoproterozoic time. 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.