Chiyomi Yamakawa

Lake Biwa Museum · Research Group

Morphological and cuticular features of Cunninghamia protokonishii were examined by studying the original material and additional fossils that were collected from the lowest Miocene to the lower Pleistocene of Japan and Korea. The species is characterized by foliar morphology that superficially resembles C. konishii, but differs by large terminal s...

A latest Pliocene (2.6 Ma) wetland forest vegetation that was dominated by Glyptostrobus and Metasequoia was reconstructed from in situ woods, fruits and seeds, and pollen assemblages in deposits of the Kobiwako Group exposed in the Yasu River, Shiga Prefecture, central Japan. Based on species composition of stumps and autochthonous plant macrofoss...

A late Pliocene (1.8–1.9 Ma) wetland fossil forest community that was dominated by Metasequoia and Glyptostrobus was reconstructed based on the species composition of the stumps and other plant macrofossil assemblages. The plant fossils were recovered from a fossil forest preserved in deposits of the Kobiwako Group that are exposed in the Echi Rive...

The Middle Pleistocene Terabayashi Formation around Mt. Ibuki, in Terabayashi, Maibara City, Shiga Prefecture, central Japan, interbeds the Terabayashi I and II volcanic ash layers that were laid down about 248-247ka ago (Late Middle Pleistocene) and which lie above the Aso-1 volcanic ash layer. The sediments correspond to oxygen isotope stages 8 t...

伊吹山山麓の寺林地域には, 年代未確定の礫質堆積層が分布している. 本論では, この堆積層を寺林層として詳細に記載した. 寺林層は, 下位から最下部層, 下部層, 中部層, 上部層の4層に区分される. 基盤岩の凹地を直接埋める最下部層は, 縞状泥層, 有機質泥層, 基質支持の塊状礫層からなる. 下部層と上部層は, そのほとんどが基質支持の礫層からなっており, その主たる構成物である基質支持の礫層は土石流によって堆積した. 中部層は, 流路に堆積した砂礫堆や残留堆積物と考えられる礫支持の礫層と, それに挾まるレンズ状の砂層からなる.最下部層に挾まる寺林I, II, III火山灰層について, 岩相, 記載岩石学的性質, 火山ガラスの主要化学成分を新たに記載した. さらに, 寺林IおよびII火山灰...

Cathaya (Pinaceae) pollen was discovered from the Pliocene Koka Formation of the Kobiwako Group, Shiga Prefecture, Japan. The pollen morphology was examined with the light and scanning electron microscopes. The characteristics indicate that the bisaccate pollen is Cathaya. This discovery suggests that further study on the pollen flora of the Plio-P...