Smaller Foraminifers included within the fissure filling sediments in the northern area of the Akasaka Limestone, Gifu Prefecture, Central Japan

Abstract

Many isolated micro-fossils consisting of various biota have been obtained from the unconsolidated fissure filling sediments developed in the Upper and Uppermost Formations of the Permian Akasaka Limestone, Gifu Prefecture, Central Japan. The tests of all the specimens sustain some influences of mechanical and chemical actions. Therefore the detailed paleontological description of the Smaller foraminifera is impossible. However, the identification at generic level is possible based on the chamberform and arrangement conjectured from the scanning electoronic micrographs of the inner casts. They are variostomatids, Climaccammina spp., Cribrogenerina spp., Nankinella sp., cf. Geinitzina sp.,and cf. Astacolus sp. It is noteworthy that the last two species and some variostomatid specimens can not be compared with any Permian species, but have characteristics very similar to those reported from the Lower Triassic in China.