Shiftings of the Mississippi River in relation to glaciation

Abstract

Research Article| September 01, 1942 Shiftings of the Mississippi River in relation to glaciation FRANK LEVERETT FRANK LEVERETT Search for other works by this author on: GSW Google Scholar GSA Bulletin (1942) 53 (9): 1283–1298. https://doi.org/10.1130/GSAB-53-1283 Article history received: 02 Jan 1942 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 FRANK LEVERETT; Shiftings of the Mississippi River in relation to glaciation. GSA Bulletin 1942;; 53 (9): 1283–1298. doi: https://doi.org/10.1130/GSAB-53-1283 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 Preglacial drainage of the present Mississippi watershed was in two distinct systems. A western system headed in southern Minnesota and flowed southeastward across northeastern Iowa to Muscatine, thence southward along the present course, except for a few miles opposite the lower rapids. The eastern system from St. Paul, Minnesota, southward to the upper rapids, turned eastward at LeClaire, Iowa, and discharged through the lower part of the Illinois valley.These drainage systems were displaced and shifted back and forth by ice sheets lying both east and west of the river. In the Nebraskan and Kansan stages disturbance by the Keewatin ice sheet initiated the cutting of a new valley from Muscatine eastward to the old eastern drainage. In the third or Illinoian stage the Labrador ice sheet covered the eastern system below Clinton, Iowa, and forced all of the drainage into a brief or temporary course through eastern Iowa outside the Illinoian ice border. When the Illinoian ice sheet melted drainage from eastern Iowa down the old valley south from Muscatine was reopened. The entire present Mississippi became established in early Wisconsin time, about 80,000 years ago. In late Wisconsin time it also carried the Glacial Lake Agassiz drainage. 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.