Cyclostratigraphy and eccentricity tuning of the early Oligocene through early Miocene (30.1-17.1 Ma); Cibicides mundulus stable oxygen and carbon isotope records from Walvis Ridge Site 1264

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doi: 10.1016/j.epsl.2016.06.007
Author(s): Liebrand, Diederik; Beddow, Helen M.; Lourens, Lucas J.; Palike, Heiko; Raffi, Isabella; Bohaty, Steven M.; Hilgen, Frederik J.; Saes, Mischa J. M.; Wilson, Paul A.; van Dijk, Arnold E.; Hodell, David A.; Kroon, Dick; Huck, Claire E.; Batenburg, Sietske J.
Author Affiliation(s): Primary:
University of Southampton, National Oceanography Centre Southampton, Southampton, United Kingdom
Other:
Utrecht University, Netherlands
Universita degli Studi "G. d'Annunzio" di Chieti-Pescara, Italy
University of Cambridge, United Kingdom
University of Edinburgh, United Kingdom
Goethe-University Frankfurt am Main, Germany
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.450, p.392-405. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. Includes appendix. 52 refs.; illus., incl. 1 table
Summary: Few astronomically calibrated high-resolution (≤5 kyr) climate records exist that span the Oligocene-Miocene time interval. Notably, available proxy records show responses varying in amplitude at frequencies related to astronomical forcing, and the main pacemakers of global change on astronomical time-scales remain debated. Here we present newly generated X-ray fluorescence core scanning and benthic foraminiferal stable oxygen and carbon isotope records from Ocean Drilling Program Site 1264 (Walvis Ridge, southeastern Atlantic Ocean). Complemented by data from nearby Site 1265, the Site 1264 benthic stable isotope records span a continuous ∼13-Myr interval of the Oligo-Miocene (30.1-17.1 Ma) at high resolution (∼3.0 kyr). Spectral analyses in the stratigraphic depth domain indicate that the largest amplitude variability of all proxy records is associated with periods of ∼3.4 m and ∼0.9 m, which correspond to 405- and ∼110-kyr eccentricity, using a magnetobiostratigraphic age model. Maxima in CaCO3 content, δ18O and δ13C are interpreted to coincide with ∼110 kyr eccentricity minima. The strong expression of these cycles in combination with the weakness of the precession- and obliquity-related signals allow construction of an astronomical age model that is solely based on tuning the CaCO3 content to the nominal (La2011\ecc3L) eccentricity solution. Very long-period eccentricity maxima (∼2.4-Myr) are marked by recurrent episodes of high-amplitude ∼110-kyr δ18O cycles at Walvis Ridge, indicating greater sensitivity of the climate/cryosphere system to short eccentricity modulation of climatic precession. In contrast, the responses of the global (high-latitude) climate system, cryosphere, and carbon cycle to the 405-kyr cycle, as expressed in benthic δ18O and especially δ13C signals, are more pronounced during ∼2.4-Myr minima. The relationship between the recurrent episodes of high-amplitude ∼110-kyr δ18O cycles and the ∼1.2-Myr amplitude modulation of obliquity is not consistent through the Oligo-Miocene. Identification of these recurrent episodes at Walvis Ridge, and their pacing by the ∼2.4-Myr eccentricity cycle, revises the current understanding of the main climate events of the Oligo-Miocene.
Year of Publication: 2016
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Benthic taxa; Carbon; Carbon cycle; Cenozoic; Cibicides; Cibicides mundulus; Climate forcing; Cyclostratigraphy; Eccentricity; Foraminifera; Geochemical cycle; Invertebrata; Isotope ratios; Isotopes; Leg 208; Microfossils; Miocene; Neogene; O-18/O-16; ODP Site 1264; ODP Site 1265; Obliquity of the ecliptic; Ocean Drilling Program; Oligocene; Orbital forcing; Orbitoidacea; Oxygen; Paleoclimatology; Paleogene; Precession; Protista; Rotaliina; South Atlantic; Stable isotopes; Tertiary; Walvis Ridge
Coordinates: S283200 S283200 E0025100 E0025100
S285000 S285000 E0023800 E0023800
Record ID: 2016081445
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands