Kawamagari Fm - Asakusa (Eocene of Japan)

Where: Japan (32.4° N, 130.2° E: paleocoordinates 39.3° N, 125.4° E)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Kawamagari Formation, Late/Upper Eocene (37.2 - 33.9 Ma)

• STRATIGRAPHIC RELATIONS: From Kawamagari Fm, which locally overlies the Hoshuyama Fm (Middle Eocene), and is overlain by the Doshi Fm (Late Eocene). THICKNESS: From formation that attains a thickness of <50 m. AGE: Late Eocene, based on molluscan biostratigraphy. STRATIGRAPHIC POSITION: Composite list for the formation in this local area.

• formation-level stratigraphic resolution

Environment/lithology: coastal; lithified, glauconitic, green sandstone

• ENVIRONMENT: Shallow sea, soft-bottom siliciclastic bottom.
• SPECIFIC LITHOLOGY: Green-colored, glauconitic sandstone. LITHIFICATION: Presumed lithified on the basis of age.

Size class: macrofossils

Collection methods: surface (float),

• COLLECTOR: Nagao (c. 1928). REPOSITORY: Not stated in text, unknown.

Primary reference: A. Mizuno. 1964. Paleogene and Early Neogene molluscan faunae in West Japan. Geological Survey of Japan Report 204 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 70926: authorized by Austin Hendy, entered by Austin Hendy on 11.04.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for gastropoda and bivalvia. NOMENCLATURE: Farly modern nomenclature, and species-level assignments.
Bivalvia
 Ostreida - Pinnidae
Pinna asakuraensis Nagao 1928 oyster
 Mytilida - Mytilidae
Crenella striatocostata Nagao 1928 mussel
 Carditida - Carditidae
 Cardiida - Veneridae
 Lucinida - Lucinidae
"Eomiltha sp." = Gibbolucina (Eomiltha)
"Eomiltha sp." = Gibbolucina (Eomiltha) Cossmann 1912 clam
 Nuculida - Nuculidae
Gastropoda
 Neogastropoda - Buccinidae
 Neogastropoda - Volutidae
Volutospina ? nishimurai Nagao 1928 volute
 Stromboidea - Strombidae
"Rimella" sp. Agasiz 1841 true conch
 Stromboidea - Thersiteidae
"Orthaulax" japonicus Nagao 1924 snail