Magnetostratigraphy of Upper Cretaceous (Lancian) to Middle Paleocene (Tiffanian) strata in the northeastern Crazy Mountains Basin, Montana, U.S.A.

Research Article| November 01, 2018 Magnetostratigraphy of Upper Cretaceous (Lancian) to Middle Paleocene (Tiffanian) strata in the northeastern Crazy Mountains Basin, Montana, U.S.A. Gregory A. Buckley Gregory A. Buckley Department of Physics and Earth Science, UNA Box 5065, University of North Alabama, Florence, Alabama 35632-0001, U.S.A. email: gbuckley@una.edu Search for other works by this author on: GSW Google Scholar Author and Article Information Gregory A. Buckley Department of Physics and Earth Science, UNA Box 5065, University of North Alabama, Florence, Alabama 35632-0001, U.S.A. email: gbuckley@una.edu Publisher: University of Wyoming Received: 29 May 2018 Revision Received: 30 Sep 2018 Accepted: 12 Nov 2018 First Online: 27 Nov 2018 Online Issn: 1555-7340 Print Issn: 1555-7332 © 2018, University of WyomingUniversity of Wyoming Rocky Mountain Geology (2018) 53 (2): 59–74. https://doi.org/10.24872/rmgjournal.53.2.59 Article history Received: 29 May 2018 Revision Received: 30 Sep 2018 Accepted: 12 Nov 2018 First Online: 27 Nov 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Gregory A. Buckley; Magnetostratigraphy of Upper Cretaceous (Lancian) to Middle Paleocene (Tiffanian) strata in the northeastern Crazy Mountains Basin, Montana, U.S.A.. Rocky Mountain Geology 2018;; 53 (2): 59–74. doi: https://doi.org/10.24872/rmgjournal.53.2.59 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 SocietyRocky Mountain Geology Search Advanced Search ABSTRACT A magnetostratigraphic study in the northeast part of the Crazy Mountains Basin of Montana sampled strata that includes both the Cretaceous–Paleogene boundary sequence as well as numerous, well-documented fossil mammal and invertebrate localities. Ninety-five horizons were sampled from nine separate sections, with a composite stratigraphic range from the upper part of the Hell Creek Formation, through the Bear and Lebo Members of the Fort Union Formation, and into the lower part of the Melville Member of the Fort Union. Data show that the (1) Hell Creek Formation–Bear Member contact lies within a magnetozone of reverse polarity (chron C29r); (2) Simpson Quarry and the Bear Member–Lebo Member contact occurs within the overlying normal polarity magnetozone (chron C29n); (3) magnetozones defining chron C28 fall completely within the Lebo Member; and (4) Gidley and Silberling quarries and the Lebo Member–Melville Member contact occurs within a reverse polarity magnetozone (chron C27r). The resulting high-resolution chronostratigraphic framework—incorporating both biostratigraphic and magnetostratigraphic data—places the Crazy Mountains Basin strata and fossil localities into a more well-defined context with other depositional basins in the Western Interior of North America. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.