白亜系の国際対比と古地磁気学  [in Japanese] Paleomagnetism and international correlation of the Cretaceous System  [in Japanese]

Paleomagnetic methods relevant with the international correlation of the Cretaceous System are reviewed. Paleomagnetic works can contribute to the geological correlation by two means: One is as a magnetic reversal time marker, and the other is as a direction pointer for the paleoreconstruction of oceans and continents. Focussing on the correlation of the Japanese Cretaceous system with other areas, we find several specific problems. In this paper, we note, at first, some technical problems concerning with the identification of the primary remanent magnetization of relatively old rocks from orogenic belt such as Japanese Islands. Secondly, we refer to the recent status of the geomagnetic reversal time scal e ofCretaceous period, which ischaracterized by the presence of long normal polarity interval called as Cretaceous Normal Superchron. Lastly, some recent topics on the apparent polar wander path (APWP) relative to the Eurasian plate are presented. APWP for Eurasia is only conventional reference to make discussion about the paleoposition of the Japanese Islands at the present stage of the study.