High-resolution 10Be and paleomagnetic recording of the last polarity reversal in the Chiba composite section: Age and dynamics of the Matuyama–Brunhes transition

Autor: Quentin Simon, Karim Keddadouche, Yusuke Suganuma, Makoto Okada, Georges Aumaître, Yuki Haneda, D.L. Bourles
Přispěvatelé: Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), JSPS Kakenhi GrantMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of ScienceGrants-in-Aid for Scientific Research (KAKENHI) [16H04068, 15K13581, 17H06321], INSU/CNRSCentre National de la Recherche Scientifique (CNRS), ANR through the EQUIPEX 'ASTER-CEREGE' actionFrench National Research Agency (ANR), IRD, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Earth and Planetary Science Letters
Earth and Planetary Science Letters, Elsevier, 2019, 519, pp.92-100. ⟨10.1016/j.epsl.2019.05.004⟩
Earth and Planetary Science Letters, 2019, 519, pp.92-100. ⟨10.1016/j.epsl.2019.05.004⟩
Earth And Planetary Science Letters (0012-821X) (Elsevier BV), 2019-08, Vol. 519, P. 92-100
ISSN: 0012-821X
DOI: 10.1016/j.epsl.2019.05.004⟩
Popis: International audience; We present new magnetic (direction and relative paleointensity) and beryllium isotope (10 Be, 9 Be and 10 Be/ 9 Be ratio) results covering the last geomagnetic reversal, i.e., the Matuyama-Brunhes transition (MBT), from the Chiba composite section (CbCS), east-central Japan. The very high sedimentation rates (>90 cm/ka) of the studied site, a candidate site for the global boundary stratotype section and point (GSSP) of the Lower-Middle Pleistocene boundary, allow the acquisition of a dataset of exceptional resolution. Coupled cosmogenic 10 Be and magnetic results measured on the same samples demonstrate that the magnetization acquisition conserved the timing of rapid geomagnetic features, allowing accurate paleomagnetic interpretations. A polarity switch (PS) capturing most of the angular deviation occurring between 771.9 and 773.9 ka was followed by a directional instability rebound (IC1) until 768.5 ka. This sequence with 5.4 ka duration was characterized by a weak dipole field as low as 2.3 ± 0.3 × 10 22 Am 2. Four rapid episodes of directional instabilities preceding and following the PS-IC1 phase completed the reversal sequence. The asymmetry observed between the long-term dipole decay and sharp recovery, and rapid oscillations (
Databáze: OpenAIRE
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