Mudstone facies, Ikushunbetsu River - Poronai Fm: Late Eocene, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Bivalvia
- Protobranchia
- Nuculidae
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| 5 specimens | |||||||
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Bivalvia
- Protobranchia
- Yoldiidae
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| 2 specimens | |||||||
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Bivalvia
- Protobranchia
- Sareptidae
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| 6 specimens | |||||||
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Bivalvia
- Protobranchia
- Malletiidae
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| 6 specimens | |||||||
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Bivalvia
- Carditida
- Carditidae
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| 17 specimens | |||||||
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Bivalvia
- Lucinida
- Thyasiridae
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Conchocele bisecta
(Conrad 1849)
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3 specimens | ||||||
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Gastropoda
- Naticidae
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Euspira sp.
Agassiz 1837
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1 specimen | ||||||
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Gastropoda
- Neogastropoda
- Colidae
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| 1 specimen | |||||||
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Gastropoda
- Turritellidae
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| 8 specimens | |||||||
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Turritella sp. sensu lato
Lamarck 1799
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2 specimens | ||||||
| see common names | |||||||
Geography
| Country: | Japan |
| Coordinates: | 43.3° North, 142.0° East (view map) |
| Paleocoordinates: | 48.8° North, 136.1° East (Wright 2013) |
| Basis of coordinate: | based on nearby landmark |
| Geographic resolution: | small collection |
Time
| Period: | Paleogene | Epoch: | Eocene |
| Stage: | Priabonian | 10 m.y. bin: | Cenozoic 3 |
| Key time interval: | Late Eocene | ||
| Age range of interval: | 37.71 - 33.9 m.y. ago |
Stratigraphy
| Formation: | Poronai | ||||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: STRATIGRAPHIC RELATIONS: From Poronai Fm. Relationships to adjacent units not stated in text. THICKNESS: Sample from mudstone surrounding concretion. AGE: Poronian stage, Late Eocene. STRATIGRAPHIC POSITION: From B zone of Teshima (1955), although the position of this zone relative to the entire formation is not stated in text. | |||||
Lithology and environment
| Primary lithology: | gray poorly lithified mudstone |
| Secondary lithology: | "siliciclastic" |
| Includes fossils? | Y |
| Lithology description: SPECIFIC LITHOLOGY: Dark gray mudstone. LITHIFICATION: Poorly-lithified based on figures. | |
| Environment: | basinal (siliciclastic) |
| Geology comments: ENVIRONMENT: Sublittoral-bathyal molluscan fauna. Foraminiferal assemblage suggests that maximum water depth was no more than 350 m. Assigned to a basinal environment. | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
| Articulated whole bodies: | many |
| Spatial resolution: | autochthonous |
Collection methods and comments
| Collection methods: | bulk,field collection |
| Reason for describing collection: | paleoecologic analysis |
| Collection method comments: COLLECTOR: K. Amano and R. G. Jenkins (c. 2006). REPOSITORY: Joetsu University of Education (JUE). | |
| Taxonomic list comments:COVERAGE: Exhaustive for bivalvia and gastropoda. NOMENCLATURE: Not an authoriative publication, but with modern nomenclature, species and subgenus-level assignments. | |
Metadata
| Database number: | 71010 | ||
| Authorizer: | A. Hendy | Enterer: | A. Hendy | Research group: | marine invertebrate |
| Created: | 2007-04-14 09:42:40 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | authorizer only | Released: | 2007-04-14 09:42:38 |
| Creative Commons license: | CC0 |
Reference information
Primary reference:
| 23797. | K. Amano and R. G. Jenkins. 2007. Eocene drill holes in cold-seep bivalves of Hokkaido, northern Japan. Marine Ecology 28:108-114 [A. Hendy/A. Hendy] |