[SEM20-P03] Variation of geomagnetic field intensity at about 30 Ma recorded in the Ethiopian flood basalt
Keywords:paleointensity, Ethiopian flood basalt
An overall mean of the paleointensity data is 13.2±10.9 µT and an averaged virtual dipole moment (VDM) is 2.7±2.3 1022 Am2, indicating a weak intensity at about 30 Ma in the past 10 million years. Among seven polarity zones recorded in the lave sequences, a normal polarity one shows very low intensity (4.5±2.7 µT) with smaller variation of intensity, and the VDM variation shows a tendency that the VDM was weaker in normal polarity zones than reverse polarity ones. In a period when polarity changes occurred in short intervals, a larger variation of VDM is observed, and higher values of VDM are detected from samples with large co-latitude of VGP from a mean paleomagnetic pole of the lava sequences.