Global environmental changes preceding the Cretaceous-Tertiary boundary: Early-late Maastrichtian transition

Abstract

Research Article| October 01, 1994 Global environmental changes preceding the Cretaceous-Tertiary boundary: Early-late Maastrichtian transition Enriqueta Barrera Enriqueta Barrera 1Department of Geological Sciences, University of Michigan Ann Arbor, Michigan 48109-1063 Search for other works by this author on: GSW Google Scholar Author and Article Information Enriqueta Barrera 1Department of Geological Sciences, University of Michigan Ann Arbor, Michigan 48109-1063 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 (10): 877–880. https://doi.org/10.1130/0091-7613(1994)022<0877:GECPTC>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 Enriqueta Barrera; Global environmental changes preceding the Cretaceous-Tertiary boundary: Early-late Maastrichtian transition. Geology 1994;; 22 (10): 877–880. doi: https://doi.org/10.1130/0091-7613(1994)022<0877:GECPTC>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 Stable carbon, oxygen, and strontium isotope data from Maastrichtian planktic and benthic foraminifera from southern high-latitude Ocean Drilling Program Sites 690, 750, and 761 reveal major changes in climate and ocean chemistry during the early to late Maastrichtian transition, some 4 to 6 m.y. prior to the Cretaceous-Tertiary (K-T) boundary. The δ18O results suggest accelerated cooling, resulting in the lowest marine temperatures of the Late Cretaceous. The late Maastrichtian rise in the seawater 87Sr/86Sr ratio begins at the time of this change and suggests increased rates of continental weathering and/or runoff. The δ13C values show a negative shift of ∼0.5‰ followed by a positive shift of ∼1‰. These δ13C fluctuations may reflect change in deep water chemistry with cooling, variation in reduced carbon storage in coastal areas caused by eustatic sea-level fluctuation, and increased surface-water productivity. These findings contradict the common representation of stable and climatically equable environmental conditions in the latest Cretaceous before the K-T boundary event. 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.