Benthic foraminifera at the Cretaceous-Tertiary boundary around the Gulf of Mexico

Research Article| October 01, 2001 Benthic foraminifera at the Cretaceous-Tertiary boundary around the Gulf of Mexico Laia Alegret; Laia Alegret 1Departamento de Ciencias de la Tierra, Universidad de Zaragoza, 50009 Zaragoza, Spain Search for other works by this author on: GSW Google Scholar Eustoquio Molina; Eustoquio Molina 1Departamento de Ciencias de la Tierra, Universidad de Zaragoza, 50009 Zaragoza, Spain Search for other works by this author on: GSW Google Scholar Ellen Thomas Ellen Thomas 1Departamento de Ciencias de la Tierra, Universidad de Zaragoza, 50009 Zaragoza, Spain Search for other works by this author on: GSW Google Scholar Author and Article Information Laia Alegret 1Departamento de Ciencias de la Tierra, Universidad de Zaragoza, 50009 Zaragoza, Spain Eustoquio Molina 1Departamento de Ciencias de la Tierra, Universidad de Zaragoza, 50009 Zaragoza, Spain Ellen Thomas 1Departamento de Ciencias de la Tierra, Universidad de Zaragoza, 50009 Zaragoza, Spain Publisher: Geological Society of America Received: 29 Jan 2001 Revision Received: 10 May 2001 Accepted: 31 May 2001 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2001) 29 (10): 891–894. https://doi.org/10.1130/0091-7613(2001)029<0891:BFATCT>2.0.CO;2 Article history Received: 29 Jan 2001 Revision Received: 10 May 2001 Accepted: 31 May 2001 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 Laia Alegret, Eustoquio Molina, Ellen Thomas; Benthic foraminifera at the Cretaceous-Tertiary boundary around the Gulf of Mexico. Geology 2001;; 29 (10): 891–894. doi: https://doi.org/10.1130/0091-7613(2001)029<0891:BFATCT>2.0.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 Cretaceous-Tertiary (K-T) boundary sections in northeastern Mexico contain marly formations separated by a controversial clastic unit. Benthic foraminifera in seven sections indicate middle and lower bathyal depths of deposition for the marls, with the exception of the upper bathyal northernmost section. Mixed neritic-bathyal faunas were present in the clastic unit, indicating redeposition in the deep basin by mass-wasting processes resulting from the K-T bolide impact in the Gulf of Mexico. Benthic foraminifera in the Mexican sections, and at other deep-sea locations, were not subject to major extinction at the time of impact, but there were temporary changes in assemblage composition. Benthic faunas indicate well- oxygenated bottom waters and mesotrophic conditions during the late Maastrichtian and increased food supply during the latest Maastrichtian. The food supply decreased drastically just after the K-T boundary, possibly because of the collapse of surface productivity. Cretaceous and early Paleogene benthic foraminifera, however, did not exhibit the benthic-pelagic coupling of present-day faunas, as documented by the lack of significant extinction at the K-T collapse of surface productivity. Much of the food supplied to the benthic faunas along this continental margin might have been refractory material transported from land or shallow coastal regions. The decrease in food supply at the K-T boundary might be associated with the processes of mass wasting, which removed surface, food-rich sediment. Benthic faunas show a staggered pattern of faunal recovery in the lowermost Paleogene, consistent with a staged recovery of the vertical organic flux but also with a gradual buildup of organic matter in the sediment. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.