Astronomically tuned age model for the early Eocene carbon isotope events; a new high-resolution δ13Cbenthic record of ODP Site 1263 between ≈49 and ≈54 Ma

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doi: 10.1127/nos/2016/0077
Author(s): Lauretano, V.; Hilgen, F. J.; Zachos, J. C.; Lourens, L. J.
Author Affiliation(s): Primary:
Utrecht University, Department of Earth Sciences, Utrecht, Netherlands
Other:
University of California Santa Cruz, United States
Volume Title: Newsletters on Stratigraphy
Source: Newsletters on Stratigraphy, 49(2), p.383-400. Publisher: Gebrüder Bornträger, Berlin-Stuttgart, Germany. ISSN: 0078-0421 CODEN: NLSGAO
Note: In English. 51 refs.
Summary: The early Eocene represents a time of major changes in the global carbon cycle and fluctuations in global temperatures on both short- and long-time scales. These perturbations of the ocean-atmosphere system have been linked to orbital forcing and changes in net organic carbon burial, but accurate age models are required to disentangle the various forcing mechanisms and assess causal relationships. Discrepancies between the employed astrochronological and radioisotopic dating techniques prevent the construction of a robust time frame between ∼ 49 and ∼ 54 Ma. Here we present an astronomically tuned age model for this critical time period based on a new high-resolution benthic δ13 C record of ODP Site 1263, SE Atlantic. First, we assess three possible tuning options to the stable long-eccentricity cycle (405-kyr), starting from Eocene Thermal Maximum 2 (ETM2, ∼ 54 Ma). Next we compare our record to the existing bulk carbonate δ13 C record from the equatorial Atlantic (Demerara Rise, ODP Site 1258) to evaluate our three initial age models and compare them with alternative age models previously established for this site. Finally, we refine our preferred age model by expanding our tuning to the 100-kyr eccentricity cycle of the La2010d solution. This solution appears to accurately reflect the long- and short-term eccentricity-related patterns in our benthic δ13 C record of ODP Site 1263 back to at least 52 Ma and possibly to 54 Ma. Our time scale not only aims to provide a new detailed age model for this period, but it may also serve to enhance our understanding of the response of the climate system to orbital forcing during this super greenhouse period as well as trends in its background state.
Year of Publication: 2016
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Astronomical time scale; Atlantic Ocean; C-13; Carbon; Carbon cycle; Carbonate rocks; Cenozoic; Chalk; Clastic rocks; Clastic sediments; Cyclic processes; Demerara Rise; Eocene; Eocene Thermal Maximum 2; Equatorial Atlantic; Foraminifera; Geochemical cycle; Invertebrata; Isotopes; Leg 207; Leg 208; Lower Eocene; Marl; Microfossils; North Atlantic; Northwest Atlantic; ODP Site 1258; ODP Site 1263; Ocean Drilling Program; Ooze; Paleoclimatology; Paleogene; Protista; Sedimentary rocks; Sediments; South Atlantic; Southeast Atlantic; Stable isotopes; Tertiary; Time scales; Walvis Ridge; West Atlantic
Coordinates: S283200 S283200 E0024700 E0024700
N092600 N092600 W0544400 W0544400
Record ID: 2017045439
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from Geoline, Bundesanstalt fur Geowissenschaften und Rohstoffe, Hanover, Germany