RT journal article
T1 Integrated astrochronology of the Barremian Stage (Early Cretaceous) and its biostratigraphic subdivisions
A1 Martinez, Mathieu
A1 Aguado, Roque
A1 Company, Miguel
A1 Sandoval, Jose
A1 O'Dogherty Luy, Luis Carlos
A2 Ciencias de la Tierra
K1 Barremian Stage
K1 Early Cretaceous
K1 Astrochronology
K1 Milankovitch
K1 Episodes of environmental change
AB The ages and durations of the stages in the Early Cretaceous commonly show discrepancies of several million years when the Geologic Time Scale (2020) from the International Commission of Stratigraphy (ICS) and recently published radio-astrochronologic data are compared. Here, we provide an astronomical time scale for the Barremian Stage and its subdivisions based on spectral analyses performed on magnetic susceptibility and calcium carbonate content series in two sections studied located in the Subbetic Domain of southeastern Spain. The sections are tied to Tethyan ammonite and calcareous nannofossil zones, allowing detailed correlations with other sections in the Subbetic Domain and other basins in the Tethyan Realm. Eccentricity cycles are observed throughout the series and can be correlated with the eccentricity cycles observed in other sections in the Subbetic Domain, showing that the results are reproducible. Based on the number of 405-kyr eccentricity cycles in the study interval, and considering uncertainties linked to variations in the sedimentation rates within an eccentricity cycle, the duration of the Barremian Stage is calculated at 4.58����� 0.29 +0.15 Myr. From the astronomical time scale proposed here, together with recently published radio-astrochronological studies, the base of the Barremian Stage is dated at 125.98 ± 0.21 Ma and the top at 121.40 ± 0.34 Ma. The age of the Barremian/Aptian boundary differs from the ICS Geologic Time Scale 2020 by 3.6 Myr, but fits with the age of the base of magnetochron M0r recently deduced from a synthesis of radiochronologic data. The episodes of environmental change of the late Hauterivian–Barremian show an average pacing of 2.2 Myr, suggesting an orbital control on the expansion of oceanic anoxic conditions in the Tethys.
PB Elsevier
SN 0921-8181
YR 2020
FD 2020
LK http://hdl.handle.net/10498/35274
UL http://hdl.handle.net/10498/35274
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 11-nov-2026