OM-13 - Omagari Formation, Tokomuro district: Late/Upper Oligocene, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda
- Naticidae
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Neverita asagaiensis
(Makiyama 1934)
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R category | ||||||
Gastropoda
- Neogastropoda
- Buccinidae
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Neptunea modestoides
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R category | ||||||
Bivalvia
- Nuculida
- Nuculidae
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Nucula omagariensis
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VA category | ||||||
Acila brevis
Nagao and Huzioka 1941
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C category | ||||||
recombined as Acila (Acila) brevis | |||||||
Bivalvia
- Carditida
- Carditidae
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Cyclocardia laxata
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C category | ||||||
Cyclocardia tokudai
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VA category | ||||||
see common names |
Geography
Country: | Japan |
Coordinates: | 42.8° North, 143.7° East (view map) |
Paleocoordinates: | 44.1° North, 141.3° East |
Basis of coordinate: | based on nearby landmark |
Geographic resolution: | small collection |
Time
Period: | Paleogene | Epoch: | Oligocene |
Stage: | Chattian | 10 m.y. bin: | Cenozoic 4 |
Key time interval: | Late/Upper Oligocene | ||
Age range of interval: | 27.82000 - 23.03000 m.y. ago |
Stratigraphy
Formation: | Omagari | ||||
Stratigraphic resolution: | bed | ||||
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From Omagari Fm of the Ombetsu Gp, which overlies the Shakubetsu Fm of the Urahaoro Gp (Early Oligocene) and is overlain by the Charo Fm of the Ombetsu Gp (Late Oligocene). THICKNESS: From bed with unit 60-160 m thick. AGE: Late Oligocene based on molluscan biostratigraphy. STRATIGRAPHIC POSITION: Unknown position within formation. |
Lithology and environment
Primary lithology: | lithified conglomeratic sandstone |
Includes fossils? | Y |
Lithology description: SPECIFIC LITHOLOGY: Conglomerate sandstone. LITHIFICATION: Assumed to be lithifed on the basis of figured specimens and age. | |
Environment: | coastal indet. |
Geology comments: ENVIRONMENT: Coastal marine, siliciclastic environment. |
Taphonomy
Modes of preservation: | body |
Size of fossils: | macrofossils |
Collection methods and comments
Collection methods: | field collection |
Reason for describing collection: | taxonomic analysis |
Collection method comments: COLLECTOR: Presumably S. Yui (c. 1975). REPOSITORY: Probably Tohoku University, Japan. | |
Taxonomic list comments:COVERAGE: Exhaustive for gastropoda, bivalvia and scaphopoda. NOMENCLATURE: Authoritative publication, using moderately recent nomenclature, subgenus and species level designations. |
Metadata
Database number: | 70611 | ||
Authorizer: | A. Hendy | Enterer: | A. Hendy | Research group: | marine invertebrate |
Created: | 2007-03-29 19:55:21 | Last modified: | 2013-11-25 13:37:23 |
Access level: | authorizer only | Released: | 2007-03-29 19:55:20 |
Creative Commons license: | CC BY |
Reference information
Primary reference:
23698. | Y. Honda. 1989. Paleogene molluscan faunas from the Kushiro Coal Field, Eastern Hokkaido. Tohoku University, Science Report, 2nd series 60(1):1-137 [A. Hendy/A. Hendy] |