Onset of seawater 87Sr/86Sr excursion prior to Cenomanian-Turonian oceanic anoxic event 2? New Late Cretaceous strontium isotope curve from the Central Pacific Ocean

Online Access: Get full text
doi: 10.2113/gsjfr.39.4.322
Author(s): Ando, Atsushi; Nakano, Takanori; Kaiho, Kunio; Kobayashi, Toshinori; Kokado, Emi; Khim, Boo-Keun
Author Affiliation(s): Primary:
Research Institute for Humanity and Nature, Kyoto, Japan
Tohoku University, Japan
Pusan National University, South Korea
Volume Title: Journal of Foraminiferal Research
Source: Journal of Foraminiferal Research, 39(4), p.322-334. Publisher: Cushman Foundation for Foraminiferal Research, Ithaca, NY, United States. ISSN: 0096-1191 CODEN: JFARAH
Note: In English. Includes 4 appendices. 58 refs.; illus., incl. 1 table, strat. col.
Summary: A seawater Sr isotopic excursion toward lower values across the Cenomanian/Turonian boundary has been interpreted to indicate an episode of mantle plume volcanism that might have ultimately triggered Oceanic Anoxic Event (OAE) 2. However, the standard Sr isotope curve is not definitive enough to confirm the exact coincidence of the onset of the 87Sr/86Sr excursion and the genesis of OAE 2, as revealed by the black shale deposition or positive δ13C excursion. New high-precision 87Sr/86Sr data from Upper Cretaceous chalks in a diagenetically well-constrained Pacific deep-sea section (Deep Sea Drilling Project Site 463), in conjunction with δ13C stratigraphy and revised planktonic foraminiferal zonation, show that the onset of the 87Sr/86Sr shift might have predated OAE 2, presumably by >0.6 m.y. Our results point to the possibility that the massive volcanism and associated Cenomanian-Turonian global change might have preconditioned the climatic and oceanic regimes for OAE 2, but not have actually triggered the event.
Year of Publication: 2009
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Assemblages; Biostratigraphy; C-13/C-12; Carbon; Cenomanian; Chemostratigraphy; Cretaceous; DSDP Site 463; Deep Sea Drilling Project; Foraminifera; IPOD; Invertebrata; Isotope ratios; Isotopes; Leg 62; Lithostratigraphy; Mesozoic; Metals; Microfossils; Mid-Pacific Mountains; North Pacific; Northwest Pacific; Pacific Ocean; Protista; SEM data; Sr-87/Sr-86; Stable isotopes; Strontium; Turonian; Upper Cretaceous; West Pacific
Coordinates: N212101 N212101 E1744004 E1744004
Record ID: 2010007868
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Abstract, Copyright, Cushman Foundation for Foraminiferal Research, Reference includes data from GeoScienceWorld, Alexandria, VA, United States