Lithostratigraphy and calcareous microfossil biochronology of the Cretaceous strata in the Oyubari area, Hokkaido, Japan

Abstract

In the Oyubari area of central Hokkaido, the Cretaceous Yezo Group is exposed and it comprises strata ranging in age from the Albian to Campanian. This group, consisting dominantly of hemipelagic mudstone and turbidites, attains a thickness of over 8000m. This paper presents both a revised scheme of lithostratigraphy and the first calcareous planktonic microfossil records sufficient for establishing an international correlation. -from English summary