Seep facies, Ikushunbetsu River - Poronai Fm: Late Eocene, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Turritellidae
Amano et al. 2013
Gastropoda - Naticidae
Euspira sp. Agassiz 1837
1 specimen
Gastropoda - Neogastropoda - Buccinidae
Amano and Oleinik 2016
Bathyancistrolepis sp. (Habe and Ito 1968)
2 specimens
Amano and Oleinik 2016
Bivalvia - Carditida - Carditidae
Cyclocardia sp. Conrad 1867
Amano et al. 2013
Bivalvia - Venerida - Vesicomyidae
Hubertschenckia ezoensis (Yokoyama 1890)
17 specimens
Bivalvia - Lucinida - Thyasiridae
Conchocele bisecta (Conrad 1849)
45 specimens
Bivalvia - Protobranchia - Sareptidae
Amano et al. 2013
Bivalvia - Protobranchia - Yoldiidae
Yoldia sp. Möller 1842
1 specimen
Bivalvia - Protobranchia - Malletiidae
Amano et al. 2013
see common names

Geography
Country:Japan
Coordinates: 43.3° North, 142.0° East (view map)
Paleocoordinates:48.8° North, 136.1° East (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:small collection
Time
Period: Paleogene Epoch: Eocene
Stage: Priabonian 10 m.y. bin: Cenozoic 3
Key time interval: Late Eocene
Age range of interval: 37.71 - 33.9 m.y. ago
Stratigraphy
Formation:Poronai
Stratigraphic resolution:bed
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From Poronai Fm. Relationships to adjacent units not stated in text. THICKNESS: Sample from individual concretion (2m in diameter). AGE: Poronian stage, Late Eocene. STRATIGRAPHIC POSITION: From B zone of Teshima (1955), although the position of this zone relative to the entire formation is not stated in text.
Lithology and environment
Primary lithology: lithified "carbonate"
Secondary lithology: poorly lithified mudstone
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Calcareous concretion within dark gray mudstone. LITHIFICATION: Lithified based on figured specimens and facies description.
Environment:basinal (siliciclastic)
Geology comments: ENVIRONMENT: Sublittoral-bathyal molluscan fauna. Foraminiferal assemblage suggests that maximum water depth was no more than 350 m. Assigned to a basinal environment.
Taphonomy
Modes of preservation:body,concretion
Degree of concentration:concentrated
Size of fossils:macrofossils
Articulated whole bodies:many
Feeding/predation traces:drill holes
Spatial resolution:autochthonous
Collection methods and comments
Collection methods:bulk,field collection
Reason for describing collection:paleoecologic analysis
Collection method comments: COLLECTOR: K. Amano and R. G. Jenkins (c. 2006). REPOSITORY: Joetsu University of Education (JUE).
Taxonomic list comments:COVERAGE: Exhaustive for bivalvia and gastropoda. NOMENCLATURE: Not an authoriative publication, but with modern nomenclature, species and subgenus-level assignments.
Metadata
Database number:71009
Authorizer:A. Hendy, M. Uhen Enterer:A. Hendy, M. Uhen
Modifier:M. Uhen Research group:marine invertebrate
Created:2007-04-14 09:33:29 Last modified:2025-02-22 15:12:02
Access level:authorizer only Released:2008-04-14 09:33:29
Creative Commons license:CC0
Reference information

Primary reference:
23797. K. Amano and R. G. Jenkins. 2007. Eocene drill holes in cold-seep bivalves of Hokkaido, northern Japan. Marine Ecology 28:108-114 [A. Hendy/A. Hendy]

Secondary references:

70597 K. Amano, R. G. Jenkins, Y. Sako, M. Ohara, and S. Kiel. 2013. A Paleogene deep-sea methane-seep community from Honshu, Japan. Palaeogeography, Palaeoclimatology, Palaeoecology 387:126-133 [M. Uhen/M. Uhen]
70447 K. Amano and A. Oleinik. 2016. Ancistrolepidine gastropods (Buccinidae) from the upper Eocene hydrocarbon seep deposits in Hokkaido, northern Japan. The Nautilus 130(4):158-163 [M. Uhen/M. Uhen]