Astronomy and Astrophysics – Astronomy
Scientific paper
Apr 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007geoji.169...41y&link_type=abstract
Geophysical Journal International, Volume 169, Issue 1, pp. 41-59.
Astronomy and Astrophysics
Astronomy
5
40Ar/39Ar Dating, Geomagnetic Excursion, Palaeointensity
Scientific paper
Volcanic rock samples from several sites in the Society Islands, French Polynesia were found to be transitionally magnetized. To better characterize these geomagnetic events, we performed laser-heating 40Ar/39Ar dating and additional palaeomagnetic measurements on these samples. The measurements give virtual geomagnetic pole (VGP) latitudes of 0.7-52.4°N and virtual dipole moment (VDM) values of 0.433-0.682 × 1022 A m2 which are typical for the transitional geomagnetic field. These transitional events occurred at 2.77 +/- 0.02 Ma (Raiatea), 3.20 +/- 0.03 Ma (Tahaa) and 4.40 +/- 0.01 Ma (Maupiti). Considering the reported radioisotopic ages for known geomagnetic events, it is suggested the first event is a previously unknown geomagnetic excursion (Raiatea excursion) while the latter two probably correspond to known polarity transitions (upper boundary ages of the Mammoth reversed subchron and the Nunivak normal subchron). The existence of the proposed Raiatea excursion is supported by the contemporaneous palaeointensity low recognized in the relative palaeointensity stack from the equatorial Pacific.
Ishizuka Osamu
Sudo Masafumi
Uto Kozo
Yamamoto Yasufumi
No associations
LandOfFree
40Ar/39Ar ages and palaeomagnetism of transitionally magnetized volcanic rocks in the Society Islands, French Polynesia: Raiatea excursion in the upper-Gauss Chron does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with 40Ar/39Ar ages and palaeomagnetism of transitionally magnetized volcanic rocks in the Society Islands, French Polynesia: Raiatea excursion in the upper-Gauss Chron, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 40Ar/39Ar ages and palaeomagnetism of transitionally magnetized volcanic rocks in the Society Islands, French Polynesia: Raiatea excursion in the upper-Gauss Chron will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1080254