High-resolution integrated cyclostratigraphy from the Oyambre section (Cantabria, N Iberian Peninsula); constraints for orbital tuning and correlation of middle Eocene Atlantic deep-sea records

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doi: 10.1002/2017GC007367
Author(s): Dinarès-Turell, Jaume; Martínez-Braceras, Naroa; Payros, Aitor
Author Affiliation(s): Primary:
Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy
Other:
University of the Basque Country, Spain
Volume Title: Geochemistry, Geophysics, Geosystems - G<sup>3</sup>
Source: Geochemistry, Geophysics, Geosystems - G>3`, 19(3), p.787-806. Publisher: American Geophysical Union and The Geochemical Society, United States. ISSN: 1525-2027
Note: In English. 48 refs.; illus., incl. sketch map
Summary: The astronomical timescale accuracy generally exceeds other dating methods. Precise age models are pivotal for paleoclimatic research. The middle Eocene astronomical timescale has been poorly constrained due to scarcity of suitable records leading to the so call "Eocene astronomical timescale gap." We present magnetic susceptibility and color proxy records from an expanded 60 m long cyclic hemipelagic succession from the Oyambre Cape in northern Spain (∼1.3 My long stratigraphic section tuned to the ∼43.1-44.4 Ma interval in the Lutetian stage). We use the strong eccentricity amplitude modulation of precession in the sedimentary record for orbital tuning. The tuned record is correlated at precession level with previously tuned Ocean Drilling Program (ODP) Site 1260 from the equatorial Atlantic (the only oceanic record that registers geochemical variations in the precession band) and to other lower resolution deep-sea records at eccentricity level from the Southern Atlantic. Our data is consistent with a very long eccentricity minimum (driven by a ∼2.4 My periodicity) at 43.15 Ma in the orbital solutions and an age for the C20n/C20r reversal boundary at ∼43.45 Ma. However, we challenge previous correlations between these Atlantic sites (shifts of one 100 ky eccentricity cycle). Data allows to rule out correlation to either younger or older 405 ky eccentricity cycles, which constrains chronologies for the middle Eocene, emphasizing the need for consistent astrochronological frameworks involving expanded outcrops. This should aid to overcome oceanic drilling shortcomings and sedimentary complexities. Our study highlights this integration need to achieve accuracy and stability of orbital timescales underpinning Eocene paleoclimatic records. Abstract Copyright (2018), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2018
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Cantabria Spain; Cenozoic; Climate forcing; Correlation; Cyclostratigraphy; Demerara Rise; Eocene; Equatorial Atlantic; Europe; Iberian Peninsula; Leg 114; Leg 207; Leg 208; Lutetian; Magnetic properties; Magnetic susceptibility; Marine sediments; Middle Eocene; North Atlantic; Northwest Atlantic; ODP Site 1258; ODP Site 1260; ODP Site 1263; ODP Site 702; Ocean Drilling Program; Orbital forcing; Oyambre Cape; Paleoclimatology; Paleogene; Paleomagnetism; Periodicity; Quaternary; Sediments; South Atlantic; Southern Europe; Spain; Tertiary; Walvis Ridge; West Atlantic
Coordinates: N432400 N440000 W0040000 W0050000
Record ID: 2018049408
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom, Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union