Article Dans Une Revue Physics of the Earth and Planetary Interiors Année : 1994

Absolute paleointensities between 60 and 160 kyear BP from Mount Etna (Sicily)

Résumé

Paleointensity measurements were conducted on 17 distinct lava flows from Mount Etna (Sicily) in order to obtain records of absolute paleointensities for the period covering the last 60–160 kyear. A complementary aspect of this study was to improve and extend the calibration of relative paleointensities obtained for the same interval from sedimentary sequences based on absolute values of virtual axial dipole moments. Seventy-three samples have been subjected to double heating Thellier-Coe experiments under vacuum and care was taken to perform additional studies dealing with the magnetic mineralogy and to scrutinize the effects of heating upon magnetic minerals. Potassium-argon (KAr) datings provided precise ages in most cases. Absolute paleointensities were obtained with success for ten lavas flows. The succession of the virtual axial geomagnetic dipoles (VADM) oscillate between extrema centered around a mean value of 6.3 ± 2.6 × 1022 A m2. This result is in good agreement with the sedimentary record published for the same period and confirms that there has been an appreciable decrease in geomagnetic field intensity between 80 and 150 kyear.

Dates et versions

hal-03610494 , version 1 (16-03-2022)

Identifiants

Citer

Emmanuel Tric, Jean-Pierre Valet, Pierre-Yves Gillot, Isabelle Lemeur. Absolute paleointensities between 60 and 160 kyear BP from Mount Etna (Sicily). Physics of the Earth and Planetary Interiors, 1994, 85 (1-2), pp.113-129. ⟨10.1016/0031-9201(94)90011-6⟩. ⟨hal-03610494⟩
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