TY - JOUR
T1 - Lower Maastrichtian cyclostratigraphy of the Bidart section (Basque Country, SW France)
T2 - A remarkable record of precessional forcing
AU - Husson, Dorothée
AU - Thibault, Nicolas
AU - Galbrun, Bruno
AU - Gardin, Silvia
AU - Minoletti, Fabrice
AU - Sageman, Brad
AU - Huret, Emilia
N1 - Funding Information:
We thank Heather M. Stoll for providing her isotopic data of ODP Hole 762C. We thank Jaume Dinarès-Turell and an anonymous reviewer for their helpful suggestions and comments. This study was supported by the Agence Nationale de la Recherche grant ASTS-CM .
PY - 2014/2/1
Y1 - 2014/2/1
N2 - Cyclostratigraphic analysis of the Maastrichtian limestone-marl alternations of Bidart (SW France) allows the hypothesis of orbital control on lithological cycles to be evaluated. Magnetic susceptibility (MS), oxygen and carbon isotope measurements, sampled at a high resolution, are analyzed using various cyclostratigraphic tools. A statistically significant orbital signal is detected, with a remarkable record of the precession corresponding to the limestone-marl couplets. This well expressed orbital forcing allows the building of a relative cyclostratigraphic time scale for the MS and δ13C records based on the 100kyr eccentricity cycle. The total duration of the section is estimated at 1.44±0.22Myr. Correlation based on calcareous nannofossil biostratigraphy and comparison of the scaled Bidart δ13C record to the astronomically calibrated δ13C signal of ODP Hole 762C shows that the studied section extends from -71.5 to -70Ma, covering the upper part of Chron C32n.1n and 2/3 of Chron C31r. Oxygen isotope data suggest a 2°C cooling of sea-surface temperatures during the studied interval. When placed on the long-term δ18O trend of the Bidart section, this interval is here recognized as the onset of the early Maastrichtian cooling event. With its excellent record of the precessional forcing, the Bidart section, along with other sections of the Basque Country, is a useful tool for the refinement of the Maastrichtian timescale.
AB - Cyclostratigraphic analysis of the Maastrichtian limestone-marl alternations of Bidart (SW France) allows the hypothesis of orbital control on lithological cycles to be evaluated. Magnetic susceptibility (MS), oxygen and carbon isotope measurements, sampled at a high resolution, are analyzed using various cyclostratigraphic tools. A statistically significant orbital signal is detected, with a remarkable record of the precession corresponding to the limestone-marl couplets. This well expressed orbital forcing allows the building of a relative cyclostratigraphic time scale for the MS and δ13C records based on the 100kyr eccentricity cycle. The total duration of the section is estimated at 1.44±0.22Myr. Correlation based on calcareous nannofossil biostratigraphy and comparison of the scaled Bidart δ13C record to the astronomically calibrated δ13C signal of ODP Hole 762C shows that the studied section extends from -71.5 to -70Ma, covering the upper part of Chron C32n.1n and 2/3 of Chron C31r. Oxygen isotope data suggest a 2°C cooling of sea-surface temperatures during the studied interval. When placed on the long-term δ18O trend of the Bidart section, this interval is here recognized as the onset of the early Maastrichtian cooling event. With its excellent record of the precessional forcing, the Bidart section, along with other sections of the Basque Country, is a useful tool for the refinement of the Maastrichtian timescale.
KW - Carbon-isotope stratigraphy
KW - Cyclostratigraphy
KW - Maastrichtian
KW - Magnetic susceptibility
KW - Marl-limestone alternations
KW - Precession
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U2 - 10.1016/j.palaeo.2013.12.008
DO - 10.1016/j.palaeo.2013.12.008
M3 - Article
AN - SCOPUS:84893064165
VL - 395
SP - 176
EP - 197
JO - Palaeogeography, Palaeoclimatology, Palaeoecology
JF - Palaeogeography, Palaeoclimatology, Palaeoecology
SN - 0031-0182
ER -