Tenneru Formation
The Tenneru Formation (天寧層, Tenneru-sō), sometimes in older literature the Tenneru Conglomerate Member of the Chorobetsu Formation,[1]: 260 is a geological formation in southeast Hokkaidō, Japan, in the area of Kushiro.[2]: 152 Deposited between the Harutori Formation and Yūbetsu Formation in the Urahoro Group that unconformably overlies the Nemuro Group in the Nemuro Belt, the Tenneru Formation correlates with the Rushin Formation at its western end.[3] The Formation, laid down in the Late Eocene,[2]: 160 consists mainly of reddish and reddish brown conglomerate, with some sandstone and mudstone; there are several intercalated coal seams.[2]: 152 [4] New species of fauna described from the Tenneru Formation include the "Kushiro tapir" [ja] (Plesiocolopirus kushiroensis; protonym: Colodon kushiroensis),[2] and of flora, Actinidia harutoriensis, Alnus ezoensis, Aralia ezoana, Cordia japonica, Cupania japonica, Idesia kushiroensis, Lastrea kushiroensis, and Maesa nipponica.[5]: 432–4
Flora[edit]
The Tenneru Flora as described by Tanai Toshimasa in 1970 from the areas where the Tenneru Formation is exposed, with a thickness of some 300 m (980 ft), along the upper stretches of the Tokomuro River (常室川) in the western Kushiro coal field, comprises sixteen families and twenty genera, including two Pteridophytes, one Equisetum, and two conifers, the remaining species being dicotyledons:[5]: 432–4
- Family: Osmundaceae
- Genus: Osmunda
- Osmunda sachalinensis
- Genus: Osmunda
- Family: Polypodiaceae
- Genus: Lastrea
- Lastrea kushiroensis
- Genus: Lastrea
- Family: Equisetaceae
- Genus: Equisetum
- Equisetum arcticum
- Genus: Equisetum
- Family: Taxodiaceae
- Genus: Glyptostrobus
- Glyptostrobus europaeus
- Genus: Metasequoia
- Genus: Glyptostrobus
- Family: Aceraceae
- Genus: Acer
- Acer arcticum
- Genus: Acer
- Family: Actinidiaceae
- Genus: Actinidia
- Actinidia harutoriensis
- Genus: Actinidia
- Family: Alangiaceae
- Genus: Alangium
- Alangium basiobliquum
- Alangium basitruncatum
- Genus: Alangium
- Family: Araliaceae
- Genus: Aralia
- Aralia ezoana
- Genus: Aralia
- Family: Betulaceae
- Genus: Alnus
- Alnus ezoensis
- Genus: Alnus
- Family: Boraginaceae
- Genus: Cordia
- Cordia japonica
- Genus: Cordia
- Family: Cercidiphyllaceae
- Genus: Cercidiphyllum
- Cercidiphyllum eojaponicum
- Genus: Cercidiphyllum
- Family: Flacourtiaceae
- Genus: Idesia
- Idesia kushiroensis
- Genus: Idesia
- Family: Myrsinaceae
- Genus: Maesa
- Maesa nipponica
- Genus: Maesa
- Family: Platanaceae
- Genus: Platanus
- Platanus aceroides
- Platanus guillelmae
- Genus: Platanus
- Family: Sapindaceae
- Genus: Cupania
- Cupania japonica
- Genus: Cupania
- Family Ulmaceae
See also[edit]
References[edit]
- ^ Honda Yutaka (1980). "A new Chlamys from the Shitakara Formation of the Urahoro Group, Kushiro Coal Field, Eastern Hokkaido" (PDF). Transactions and Proceedings of the Palaeontological Society of Japan. New Series (117): 255–263.
- ^ a b c d Tomida Yukimitsu (1983). "A New Helaletid Tapiroid (Perissodactyla, Mammalia) from the Paleogene of Hokkaido, Japan, and the Age of the Urahoro Group" (PDF). Bulletin of the National Science Museum. Series C. 9 (4). National Science Museum: 151–163. ISSN 0385-244X.
- ^ Katagiri Takahiro; et al. (2020). "Collisional bending of the western Paleo‐Kuril Arc deduced from paleomagnetic analysis and U–Pb age determination". Island Arc. 29 (1). Wiley-Blackwell. doi:10.1111/iar.12329. hdl:2433/245933. S2CID 214485461. e12329.
- ^ Okazaki Yoshio; et al. (1965). 5万分の1地質図幅説明書 尾幌 [Explanatory Text of the Geological Map of Japan (Scale 1:50,000): Oboro] (PDF). Hokkaido Development Agency [ja].
- ^ a b Tanai Toshimasa 棚井敏雅 (1970). "The Oligocene Floras from the Kushiro Coal Field, Hokkaido, Japan". Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and Mineralogy. 14 (4): 383–514. hdl:2115/36000.