[BCG07-P03] Taxonomy of Silurian conodonts from the Yokokurayama Group, Kurosegawa tectonic zone, distributed in Kochi Prefecture
Keywords:Silurian conodonts, limestone
The group is mainly made up of clastic sedimentary rocks, except for the Fukata Formation composed of carbonate rocks. The Fukata Formation, which is about 200 m in thickness, consists of light grey, massive limestones and limestone conglomerates. Kuwano (1974) reported several Ordovician and Silurian conodonts from the formation (The Ordovician specimens are thought to be a reworked assemblage). The massive limestone comprises lime mudstone an wackestone, under a microscope, and contains macrofossil fragments and very fine-sized quartz grains. Three conodont species belonging to three genera are identified from the formation: Ozarkodina sp., Panderodus unicostatus, and Wurmiella excavata. These species indicate that the Fukata Formation was deposited during middle to late Silurian.