M. Ohno et al., PALEOMAGNETIC RECORD OVER THE PAST 35,000 YEARS OF A SEDIMENT CORE FROM OFF SHIKOKU, SOUTHWEST JAPAN, Geophysical research letters, 20(13), 1993, pp. 1395-1398
The paleomagnetism of a sediment core (KT89-18, P4), recovered from th
e sea floor off Southwest Japan, was studied to investigate geomagneti
c field variation over the past 35,000 years. Alternating fields demag
netization revealed that the remanent magnetization of the unconsolida
ted sediments was stable and not affected by any secondary overprints.
C-14 datings were made on 21 horizons, using a Tandetron accelerator
mass spectrometer, providing a detailed time scale to the core. The in
clination record agrees with that from Lake Biwa [Kawai et al., 1975],
and supports the existence of the geomagnetic excursions which had be
en found in the Lake Biwa core. The ages of the excursions are estimat
ed to be during ca. 32 ky.B.P. is similar to ca. 28 ky.B.P. and ca. 26
ky.B.P. is similar to ca. 24 ky.B.P.