Late Paleozoic foraminifers contained in limestone conglomerate of the Maizuru Group in the Oye area, Kyoto Prefecture, Japan

Abstract

Limestone conglomerate of the Permian Maizuru Group in the Oye area, Fukuchiyama City, Kyoto Prefecture is divided into two main types based on the difference of their matrices as well as that in other areas. Limestone conglomerate with a calcareous argillaceous matrix yields Lepidolina kumaensis, L. takagamiensis, and other foraminifers characteristic in the Lepidolina kumaensis fauna. Presence of Colaniella parva contained in this conglomerate as a bioclast indicates that the limestone conglomerate having the Lepidolina kumaensis fauna in the Middle and Upper formations of the Maizuru Group ranges into the Lopingian in age and is not restricted to the Capitanian (Midian) as previously thought. Pre-Capitanian fossils are exclusively found in limestone conglomerate with an arenaceous matrix in the Upper and Gujyo formations of the Maizuru Group. Various forms of foraminifers from the Early Carboniferous (Serpukhovian) to Early Permian (Artinskian) have been identified in the Oye area. Two species of Lepidolina, L. kumaensis and L. takagamiensis, are systematically described from the limestone conglomerate of calcareous argillaceous matrix.