The astronomical theory of climate and the age of the Brunhes-Matuyama magnetic reversal

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doi: 10.1016/0012-821X(94)90244-5
Author(s): Bassinot, Franck C.; Labeyrie, Laurent D.; Vincent, Edith; Quidelleur, Xavier; Shackleton, Nicholas J.; Lancelot, Yves
Author Affiliation(s): Primary:
CNRS-Luminy, Laboratoire de Géologie du Quaternaire, Marseilles, France
CNRS/CEA Centre des Faibles Radioactivités, Gif-sur-Yvette, France
Institut de Physique du Globe, Paris, France
Cambridge University, Cambridge, United Kingdom
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 126(1-3), p.91-108. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. DBT, Contrib. No. 696; Lab. Geol. Quat., Contrib. No. 94004; Cent. Faibles Radioact., Contrib. No. 1588; Inst. Phys. Globe Paris, Contrib. No. 1322. 36 refs.; illus. incl. 4 tables
Summary: Below oxygen isotope stage 16, the orbitally derived time-scale developed by Shackleton et al. [1] from ODP site 677 in the equatorial Pacific differs significantly from previous ones [e.g., 2-5], yielding estimated ages for the last Earth magnetic reversals that are 5-7% older than the K/Ar values [6-8] but are in good agreement with recent Ar/Ar dating [9-11]. These results suggest that in the lower Brunhes and upper Matuyama chronozones most deep-sea climatic records retrieved so far apparently missed or misinterpreted several oscillations predicted by the astronomical theory of climate. To test this hypothesis, we studied a high-resolution oxygen isotope record from giant piston core MD900963 (Maldives area, tropical Indian Ocean) in which precession-related oscillations in δ18O are particularly well expressed, owing to the superimposition of a local salinity signal on the global ice volume signal [12]. Three additional precession-related cycles are observed in oxygen isotope stages 17 and 18 of core MD900963, compared to the SPECMAP composite curves [4,13], and stage 21 clearly presents three precession oscillations, as predicted by Shackleton et al. [1]. The precession peaks found in the δ18O record from core MD900963 are in excellent agreement with climatic oscillations predicted by the astronomical theory of climate. Our δ18O record therefore permits the development of an accurate astronomical time-scale. Based on our age model, the Brunhes-Matuyama reversal is dated at 775±10 ka, in good agreement with the age estimate of 780 ka obtained by Shackleton et al. [1] and recent radiochronological Ar/Ar datings on lavas [9-11]. We developed a new low-latitude, Upper Pleistocene δ18O reference record by stacking and tuning the δ18O records from core MD900963 and site 677 to orbital forcing functions.
Year of Publication: 1994
Research Program: ODP Ocean Drilling Program
Key Words: 03 Geochronology; 24 Surficial Geology, Quaternary Geology; Brunhes Chron; Cenozoic; Chemostratigraphy; Cores; Cycles; Geochronology; High-resolution methods; Indian Ocean; Isotope ratios; Isotopes; Magnetic declination; Magnetostratigraphy; Marine sediments; Matuyama Chron; Milankovitch theory; O-18/O-16; Oxygen; Paleoclimatology; Paleomagnetism; Pleistocene; Quaternary; Reversals; Sediments; Stable isotopes; Time scales; Upper Cenozoic; Upper Pleistocene; Upper Quaternary
Coordinates: N050318 N050318 E0735236 E0735236
Record ID: 1994047778
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands