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Geomagnetic moment instability between 0.6 and 1.3 Ma from cosmonuclide evidence
Author(s) -
Carcaillet Julien T.,
Thouveny Nicolas,
Bourlès Didier L.
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl017550
Subject(s) - paleomagnetism , geology , earth's magnetic field , authigenic , excursion , secular variation , paleontology , magnetostratigraphy , geophysics , volcano , geomagnetic secular variation , sedimentary rock , seismology , geomagnetic reversal , magnetic field , geomagnetic storm , law , physics , quantum mechanics , political science
The reliability of paleomagnetic records as proxies of the geomagnetic field intensity is still a matter of controversy since volcanic materials hardly provide continuous records, and marine sediments are suspected to carry a remanence biased by post‐depositional realignments and/or by overprints. Such long standing debate emphasizes the need for the development of methods independent from paleomagnetism to decipher geomagnetic intensity variations. High resolution measurements of authigenic 10 Be/ 9 Be along with a detailed sedimentary record of directional and relative paleointensity variations evidence, over the 0.6–1.3 Ma time interval, frequent and recurrent excursions or short events in the late Matuyama and the early Brunhes epochs, among which two Brunhes‐Matuyama reversal precursors and an intra‐Jaramillo excursion. The results of this study confirm the idea of a highly unstable geomagnetic field as suggested by paleomagnetic evidences.