TCF 1, Iojima Coal Mine: Bartonian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Ranellidae
Cephalopoda - Nautilida - Nautilidae
Bivalvia - Venerida - Veneridae
Bivalvia - Carditida - Carditidae
Bivalvia - Limida - Limidae
see common names

Geography
Country:Japan State/province:Nagasaki
Coordinates: 32.8° North, 129.8° East (view map)
Paleocoordinates:37.7° North, 126.2° East (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period: Paleogene Epoch: Eocene
Stage: Bartonian 10 m.y. bin: Cenozoic 3
Key time interval: Bartonian
Age range of interval: 41.03 - 37.71 m.y. ago
Stratigraphy
Geological group:Iojima Formation:Okinoshima
Stratigraphic resolution:group of beds
Stratigraphy comments: According to foraminiferal and molluscan biostratigraphy, the formation is assigned in age to the Auverisian to the Bartonian (Upper Eocene). The Okinoshima Formation falls within calcareous nannofossil Subzones CP14a–CP15b of Okada and Bukry (1980) and planktic foraminiferal Zones E10–E13 of Berggren and Pearson (2005), dating to the middle Eocene. The Okinoshima Formation including calcareous nannofossils such as Reticulofenestra umbilica and Discoaster barbadiensis, indicating Zones CP14–CP15 and planktic foraminifer, Acarinina primitiva, representing Zone P14 or older (Yamaguchi et al. 2004). These biozones of planktic microfossils assign the Okinoshima Formation to 43.5–39.0 Ma (Yamaguchi & Kamiya, 2007).
Lithology and environment
Primary lithology:fine,medium,concretionary,glauconitic lithified calcareous sandstone
Secondary lithology: lithified "shale"
Includes fossils?Y
Lithology description: Fine to medium grained glauconitic sandstone with calcareous concretions, alternation with shaley intercalations.
Environment:offshore
Geology comments: The biofacies consists of samples from muddy sandstones, sandy mudstones, and mudstones, which represent bioturbation and include few sedimentary structures that indicate wave and tidal influences. The planktic/total foraminifer ratios (P/T ratios) from the Okinoshima Formation is less than 0.03, suggesting water depths shallower than about 100–150 m. The lithofacies, P/T ratios, and molluscan assemblages indicate shallow-marine environments with little to no influence by wave and tidal action. Hence, the biofacies correlates with outer-shelf environments under warm-water conditions.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils,mesofossils
Collection methods and comments
Collection methods:field collection
Reason for describing collection:taxonomic analysis
Collection method comments: Repository: Dept. of Geology, Faculty of Education, Nagasaki Univ.
Metadata
Database number:103018
Authorizer:J. Sessa Enterer:L. Eccles
Modifier:M. Clapham Research group:marine invertebrate
Created:2011-01-21 11:37:20 Last modified:2025-02-22 15:12:02
Access level:the public Released:2011-01-21 11:37:20
Creative Commons license:CC0
Reference information

Primary reference:
34846. Y. Kamada. 1973. New Eocene marine mollusca from the Takshima coal-field, Nagasaki Prefecture, Kyushu. Science Reports of the Tohoku University, Series 2: (Hatai Memorial Vol) (6)235-240 [J. Sessa/L. Eccles/L. Eccles]