Evidence from the Crow Creek Member (Pierre Shale) for an impact-induced resuspension event in the late Cretaceous Western Interior Seaway

Abstract

Research Article| December 01, 2007 Evidence from the Crow Creek Member (Pierre Shale) for an impact-induced resuspension event in the late Cretaceous Western Interior Seaway Ryan D. Weber; Ryan D. Weber 1Paleo-Data Inc., 6619 Fleur de Lis Drive, New Orleans, Louisiana 70124, USA Search for other works by this author on: GSW Google Scholar David K. Watkins David K. Watkins 2Department of Geosciences, University of Nebraska, Lincoln, Nebraska 68588, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Ryan D. Weber 1Paleo-Data Inc., 6619 Fleur de Lis Drive, New Orleans, Louisiana 70124, USA David K. Watkins 2Department of Geosciences, University of Nebraska, Lincoln, Nebraska 68588, USA Publisher: Geological Society of America Received: 26 Jan 2007 Revision Received: 31 Jul 2007 Accepted: 06 Aug 2007 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 The Geological Society of America, Inc. Geology (2007) 35 (12): 1119–1122. https://doi.org/10.1130/G24209A.1 Article history Received: 26 Jan 2007 Revision Received: 31 Jul 2007 Accepted: 06 Aug 2007 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Ryan D. Weber, David K. Watkins; Evidence from the Crow Creek Member (Pierre Shale) for an impact-induced resuspension event in the late Cretaceous Western Interior Seaway. Geology 2007;; 35 (12): 1119–1122. doi: https://doi.org/10.1130/G24209A.1 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 The 1–3-m-thick Crow Creek Member is a unique marlstone with rip-up clasts and a basal coarse layer in the Upper Cretaceous Pierre Shale in South Dakota and Nebraska. Although the Member has been thought to represent a marine transgression along the eastern margin of the Western Interior Seaway, the presence of impact ejecta from the Manson Impact Structure suggests an impact-induced genesis.An upper Campanian in situ nannofossil assemblage with a lower Campanian reworked assemblage (from older Niobrara Chalk) occurs in the Crow Creek at most localities. The reworked assemblage decreases in abundance upward through the marlstone, a pattern consistent with an origin involving gravitational settling rather than marine transgression. Gray marlstone clasts in the basal coarse layer have nannofossils derived from the underlying Gregory Member and Niobrara Chalk. The reworked assemblage decreases in abundance with increased distances from the Manson Impact Structure and the Sioux Ridge (a paleotopographic high). The nonuniform geographic distribution of reworking suggests that Crow Creek deposition was linked to the Manson Impact. These observations, and a fining upward trend, the presence of impact ejecta, and coeval deposition with the Manson Impact Structure, support a resuspension-event origin for the Crow Creek Member. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.