Shakubetsu Fm - Kushiro Coal Field: Early Oligocene, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Viviparidae
unclassified
Gastropoda - Potamididae
Gastropoda - Thiaridae
? Melanoides sp. Olivier 1804
Gastropoda - Naticidae
Bivalvia - Ostreida - Ostreidae
Bivalvia - Mytilida - Mytilidae
Mytilus sp. Linnaeus 1758
Mytilus cf. luciferus Yokoyama 1924
Modiolus sp. (Lamarck 1801)
Bivalvia - Unionida - Margaritiferidae
Margaritifera sp. Schumacher 1815
Bivalvia - Unionida - Unionidae
Bivalvia - Venerida - Corbiculidae
Bivalvia - Cardiida - Cardiidae
Nemocardium sp. Meek 1876
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:Shakubetsu
Stratigraphic resolution:formation
Stratigraphy comments: STRATIGRAPHIC RELATIONS: Uppermost unit of the Urahoro Group, lying between the Shitakara Fm (Early Oligocene) and the Omagari Formation of the Ombetsu Group (presumably Late 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:68895
Authorizer:A. Hendy Enterer:A. Hendy
Research group:marine invertebrate
Created:2007-02-12 18:27:11 Last modified:2025-02-22 15:12:02
Access level:group members Released:2007-02-12 18:27:10
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]