Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8907022 | Earth and Planetary Science Letters | 2018 | 12 Pages |
Abstract
New high-resolution authigenic 10Be/9Be ratio (Be-ratio) records covering the last geomagnetic reversal, i.e. the Matuyama-Brunhes transition (MBT), have been obtained and set on a time scale using benthic δ18O (Cibicides wuellerstorfi) records. The geographic distribution of the four studied sites allows global comparison between the North Atlantic, Indian and Pacific Oceans. All Be-ratio records contain a two-fold increase triggered by the geomagnetic dipole moment (GDM) collapse associated with the MBT. The stratigraphic position of the Be-ratio spike, relative to marine isotope stages, allows establishment of a robust astrochronological framework for the MBT, anchoring its age between 778 and 766 ka (average mid-peaks at 772 ka), which is consistent with all other available 10Be-proxy records from marine, ice and loess archives. The global 10Be atmospheric production doubling represents an increase of more than 300 atomsâmâ2âsâ1 that is compatible with the increased magnitude of atmospheric 10Be production obtained by simulations between the present GDM and a null-GDM. The minimum 10Be-derived GDM average computed for the 776-771 ka interval is 1.7±0.4Ã1022 Am2, in agreement with model simulations and absolute paleointensities of transitional lava flows.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Earth and Planetary Sciences (General)
Authors
Quentin Simon, Nicolas Thouveny, Didier L. Bourlès, Franck Bassinot, Tatiana Savranskaia, Jean-Pierre Valet, ASTER Team ASTER Team,