An age-calibrated record of upper Campanian - Maastrichtian climate change in the Boreal Realm

Author(s): Thibault, N.; Schovsbo, N.; Harlou, R.; Stemmerik, L.; Surlyk, F.
Author Affiliation(s): Primary:
University of Copenhagen, Department of Geography and Geology, Copenhagen, Denmark
Other:
Geological Survey of Denmark and Greenland, Denmark
Volume Title: AGU 2011 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2011; American Geophysical Union 2011 fall meeting, San Francisco, CA, Dec. 5-9, 2011. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English. 2 refs.
Summary: The latest Cretaceous climate of the Boreal Realm was recorded through high-resolution bulk carbon- and oxygen-stable isotopes and a nannofossil temperature index (NTI) on the Stevns-1 core (Denmark) which recovered 456 m of upper Campanian to basal Danian chalk with ∼100% recovery and an excellent continuity. Carbon isotope stratigraphy and nannofossil biostratigraphy were used to correlate Stevns-1 to two sites that bear an excellent magnetostratigraphic record: DSDP Site 525A and ODP Site 762C. The correlation of δ13C trends between the three sites and the use of the recent astronomical calibration of upper Campanian - Maastrichtian magnetochrons (Husson et al., 2011; K-Pg boundary at 66 Ma) led to the establishment of a precise age-model for Stevns-1. The good correlation between bulk δ18O and the NTI (R=-0.81) allows the use of oxygen stable isotopes to estimate past variations of sea surface temperatures (SSTs) in the Boreal Realm. Three warming events punctuate the overall cooling trend of the latest Cretaceous: (1) the late Campanian climatic optimum (73.9-71.6 Ma) is characterized by maximum SSTs of 20°C, (2) the mid-Maastrichtian warming (69.7-68 Ma) is characterized by stable SSTs around 17°C and (3) the end-Maastrichtian warming (66.37-66.03) is characterized by increasing SSTs up to 18°C. The two cooling events of the early (71.6-69.7 Ma) and late Maastrichtian (68-66.37 Ma) are both characterized by stable SSTs around 16°C. This Boreal record of SSTs derived from the δ18O of bulk nannofossil chalk is in agreement with planktic biotic events of the latest Cretaceous and matches well with climatic trends of intermediate- and deep-waters from other oceanic basins recorded through benthic foraminiferal δ18O (Barrera and Savin, 1999). However, most planktic foraminiferal δ18O data do not record well the mid- and end-Maastrichtian warmings. This suggests that the influence of changes in seawater pH and depth habitats of Campanian-Maastrichtian planktonic foraminifer species have to be reconsidered before deriving past SSTs from planktic foraminiferal δ18O data in this time interval. References Barrera, E. and Savin, S.M., 1999. In: Barrera, E., and Johnson, C.C., Eds., Evolution of the Cretaceous Ocean-Climate System: Boulder, Colorado, Geol. Soc. America Spec. Paper 332, 245-282. Husson, D., Galbrun, B., Laskar, J., Hinnov, L., Thibault, N., Gardin, S., Locklair, R., 2011. Earth Planet. Sci. Lett., 305, 328-340.
Year of Publication: 2011
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Boreal Realm; C-13/C-12; Campanian; Carbon; Climate change; Cretaceous; DSDP Site 525; Deep Sea Drilling Project; Exmouth Plateau; Foraminifera; IPOD; Indian Ocean; Isotope ratios; Isotopes; Leg 122; Leg 74; Maestrichtian; Mesozoic; Microfossils; O-18/O-16; ODP Site 762; Ocean Drilling Program; Oxygen; PH; Paleoenvironment; Paleotemperature; Sea water; Sea-surface temperature; South Atlantic; Stable isotopes; Upper Campanian; Upper Cretaceous; Walvis Ridge
Coordinates: S290415 S290414 E0025908 E0025907
Record ID: 2018028732
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