いわゆるLepidocyclina-Miogypsina ZoneとMioggpsina-Operculina Zoneの時代についての2・3の問題

概要

論文の詳細を見る
Geological age of the Lepidocyclina-Miogypsina and Miogypsina-Operculina populations in the Japanese Neogene are considered on reference to the planktonic foraminifers of the Fossa Magna and the Hokuriku districts. Generally, Lepidocyclina-Miogypsina populations occur within the interval from Blow's Zone N. 8 (partly N. 7) to early N. 9 in the Pacific side, exclusively Fossa Magna district where they possibly range up to Zone N. 10 or N. 11. Miogypsina-Operculina populations are found within the late Zone N. 8 or early Zone N. 9 in the Toyama sedimentary basin, Japan Sea side. The distribution of these two populations are distinctly in the different region and there is no example of the Miogypsina-Operculina population overlies directly on the Lepidocyclina-Miogypsina population in Japan. Almost of all Lepidocyclina-Miogypsina populations and Miogypsina-Operculina populations were extinct from Japan in the Zone 9 but the former reocurred in the Zone N. 14 only in the Izu Peninsula.
日本地質学会の論文
1973-03-31