SK2-1 - Shitakara Fm (middle), Akan district: Early Oligocene, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Bivalvia - Thraciida - Periplomatidae
R category
see common names

Geography
Country:Japan
Coordinates: 43.3° North, 144.1° East (view map)
Paleocoordinates:45.9° North, 140.7° East (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period: Paleogene Epoch: Oligocene
Stage: Rupelian 10 m.y. bin: Cenozoic 4
Key time interval: Early Oligocene
Age range of interval: 33.9 - 27.3 m.y. ago
Stratigraphy
Formation:Shitakara
Stratigraphic resolution:bed
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From Shitakara Fm of the Urahoro Gp, which overlies the Yubetsu Fm and is overlain by the Shakubetsu Fm, both of the Urahoro Gp (Early Oligocene). THICKNESS: From bed within unit 100-200 m thick. AGE: Early Oligocene based on molluscan biostratigraphy. STRATIGRAPHIC POSITION: From bed within middle part of the formation.
Lithology and environment
Primary lithology: lithified sandstone
Secondary lithology: lithified conglomerate
Includes fossils?Y
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Sandstone, conglomerate, and siltstone. 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 Y. Honda (c. 1989). 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:70732
Authorizer:A. Hendy Enterer:A. Hendy
Research group:marine invertebrate
Created:2007-04-03 23:25:42 Last modified:2025-02-22 15:12:02
Access level:authorizer only Released:2007-04-03 23:25:41
Creative Commons license:CC0
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]