Yubetsu Fm - Kushiro Coal Field: Early Oligocene, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Bivalvia - Venerida - Corbiculidae
Corbicula sp. Megerle 1811
Bivalvia - Venerida - Mactridae
Bivalvia - Ostreida - Ostreidae
see common names

Geography
Country:Japan
Coordinates: 43.0° North, 144.4° East (view map)
Paleocoordinates:45.6° North, 141.1° East (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:local area
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
Geological group:Urahoro Formation:Yubetsu
Stratigraphic resolution:formation
Stratigraphy comments: STRATIGRAPHIC RELATIONS: Near base of the Urahoro Group, which unconformably overlies the Late Cretaceous-Paleocene Kawarupu Formation of the Nemuro Group, lying between the basal Rushin Fm (Early Oligocene) and overlain by the Shitakara Formation, also of the Urahoro Group (presumably also Early Oligocene). THICKNESS: Unknown thickness of unit. AGE: Presumably Early Oligocene; from near base of Oligocene in region. STRATIGRAPHIC POSITION: Collection representative of entire formation in local area.
Lithology and environment
Primary lithology:fine,pebbly,gray lithified conglomeratic,carbonaceous sandstone
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Gray, poorly sorted, fine-grained sandstone and pebbly to granular conglomerate composed of chert pebbles, with intercalated coal seams. LITHIFICATION: Presumed lithified, on the basis of age, presence of coal, and low diversity of fauna.
Environment:marginal marine indet.
Geology comments: ENVIRONMENT: Non-marine through shallow marine.
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: Unknown collected, possibly Y. Honda. REPOSITORY: Unknown repository.
Taxonomic list comments:COMPLETENESS: Authoritative for Mollusca. NOMENCLATURE: Slightly antiquated, but with consistent use of species level and subgeneric assignments.
Metadata
Database number:68893
Authorizer:A. Hendy Enterer:A. Hendy
Research group:marine invertebrate
Created:2007-02-12 18:24:21 Last modified:2025-02-22 15:12:02
Access level:group members Released:2007-02-12 18:24:20
Creative Commons license:CC0
Reference information

Primary reference:
19891. Y. Honda. 1986. A Paleogene molluscan fauna from Hokkaido, northern Japan. Paleontological Society of Japan Special Papers 29:3-15 [A. Hendy/A. Hendy]