Loc. Y5206 - River Hakkinzawa [Yezo Gp]: Late Turonian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Cephalopoda - Ammonitida - Acanthoceratidae
Cephalopoda - Ammonitida - Collignoniceratidae
[entered as Collignoniceras woolgari]
Bivalvia - Myalinida - Inoceramidae
Inoceramus hobetsensis Nagao and Matsumoto 1939
see common names

Geography
Country:Japan County:Hokkaido
Coordinates: 43.0° North, 142.0° East (view map)
Paleocoordinates:50.6° North, 142.3° East (Wright 2013)
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period: Cretaceous Epoch: Late Cretaceous
Stage: Turonian 10 m.y. bin: Cretaceous 6
Key time interval: Late Turonian Ammonoid zone:  Romaniceras deverianum
Age range of interval: 93.9 - 89.8 m.y. ago
Stratigraphy
Geological group:Yezo
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: Late Turonian, on the basis of ammonite and inoceramid biostratigraphy; Romaniceras deverianum; originally entered as Middle Turonian. STRATIGRAPHIC POSITION: From near top of regional section.
Lithology and environment
Primary lithology:tuffaceous siltstone
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Siltstone, intercalated with acid bentonite tuff. LITHIFICATION: Not stated in text.
Environment:coastal indet.
Geology comments: ENVIRONMENT: Marine siliciclastic setting.
Taphonomy
Modes of preservation:cast,mold/impression
Size of fossils:macrofossils
Collection methods and comments
Collection excludes:some genera
Collection methods:field collection
Reason for describing collection:taxonomic 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:86986
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Created:2009-02-26 21:50:17 Last modified:2025-02-22 15:12:02
Access level:the public Released:2009-02-26 21:50:17
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]