Loc. Y5285 - River Hakkinzawa [Yezo Gp]: Early Cenomanian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Echinoidea
Malacostraca - Decapoda
Cephalopoda - Ammonitida - Forbesiceratidae
Forbesiceras sp. Kossmat 1897
Cephalopoda - Ammonitida - Tetragonitidae
see common names

Geography
Country:Japan County:Hokkaido
Coordinates: 43.0° North, 142.0° East (view map)
Paleocoordinates:49.3° North, 147.3° East (Wright 2013)
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period: Cretaceous Epoch: Late Cretaceous
Stage: Cenomanian 10 m.y. bin: Cretaceous 5
Key time interval: Early Cenomanian
Age range of interval: 100.5 - 93.9 m.y. ago
Stratigraphy
Geological group:Yezo Local bed:367.6 m
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From unnamed lithostratigraphic unit within the middle Yezo Gp, which unconformably overliesthe late Mesozoic Sorachi Gp, and is overlain by Cenozoic strata. AGE: Early Cenomanian, on the basis of ammonite and inoceramid biostratigraphy. STRATIGRAPHIC POSITION: From lower part of regional section.
Lithology and environment
Primary lithology: lithified claystone
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Poorly fossiliferous claystone. LITHIFICATION:
Environment:coastal indet.
Geology comments: ENVIRONMENT: Marine siliciclastic setting.
Taphonomy
Modes of preservation:cast,mold/impression,concretion
Size of fossils:macrofossils
Collection methods and comments
Collection excludes:some genera
Collection methods:field collection
Reason for describing collection:biostratigraphic analysis
Collection method comments: COLLECTOR: H. Hirano, T. Matsumoto, and K. Tanabe, 1970's. REPOSITORY: Dept. of Geology, Kyushu University.
Taxonomic list comments:COVERAGE: Limited to representative ammonoids and inoceramids. NOMENCLATURE: Not an authoritative publication, but with fairly modern nomenclature and species-resolution identifications.
Metadata
Database number:86985
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:G. Palazzo Research group:marine invertebrate
Created:2009-02-26 21:38:08 Last modified:2026-05-18 18:37:33
Access level:the public Released:2009-02-26 21:38:08
Creative Commons license:CC0
Reference information

Primary reference:
29265. H. Hirano, T. Matsumoto, and K. Tanabe. 1977. Mid-Cretaceous stratigraphy of the Oyubari area, central Hokkaido. Palaeontological Society of Japan Special Papers 21:1-10 [A. Hendy/A. Hendy]