Diatoms from the Onogami Formation, an Early Pleistocene Lacustrine Deposit, Central Japan

Abstract

The Onogami Formation, an early Pleistocene lacustrine deposit, is located 120 km northwest of Tokyo. Samples were collected from the type locality of the Onogami Formation. The diatom assemblages are composed of 26 species belonging to 18 genera. The diatoms of this formation are characterized by Cyclotella radiosa (Grun. ) Lemm., C. reczickiae Churs. et Log., Stephanodiscus alpinus Hust., S. sp., Aulacoseira ambigua (Grun. ) Sim., Ellerbeckia arenaria (Ralfs) Crawford var. teres (Brun. ) Crawford.