MAJ 1 (Eocene of Japan)

Where: Hokkaido, Japan (43.3° N, 141.9° E: paleocoordinates 46.3° N, 136.8° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Poronai Formation, Middle Eocene (48.6 - 37.2 Ma)

• formation-level stratigraphic resolution

Environment/lithology: slope; lithified, massive, concretionary, tuffaceous, sandy, calcareous siltstone

• The Poronai fm represents the shallow marine-shelf systsem, the fossil lithofacies represents the outer shelf to slope to basin floor.
• Massive siltstone, intercalated thin tuffaceous sandstone, and sandy tuff which is about 1600m thick. The siltstone contains calcareous concretions and glendonite.

Size classes: macrofossils, mesofossils

Primary reference: A. Suzuki. 2000. An Eocene cold-water molluscan assemblage from thr Poronai Formation in the Mikasa area, central Hokkaido, northern Japan. Earth Science (Chikyu Kagaku) 54:363-368 [J. Sessa/L. Eccles/L. Eccles]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 103769: authorized by Jocelyn Sessa, entered by Laurie Eccles on 02.02.2011

Creative Commons license: CC BY (attribution)

Taxonomic list

Foraminifera
 Buliminoidea - Buliminidae
Nodosariata
 Nodosariida - Nodosariidae
Globothalamea
 Rotaliida - Gavelinellidae
Gyroidina sp. d'Orbigny 1826
 Rotaliida - Anomalinidae
Anomalina sp. d'Orbigny 1826
Foraminifera
 Rotalioidea - Elphidiidae
 Lituolida - Lituolidae
 Lituolida - Haplophragmoididae
 Astrorhizacea - Bathysiphonidae
 Rotaliina -
Gastropoda
 Cerithioidea - Turritellidae
Orectospira wadana turret shell
 Neogastropoda - Buccinidae
Neptunea sp. Röding 1798 true whelk
Bivalvia
 Lucinida - Thyasiridae
Conchocele bisecta Conrad 1849 clam
 Thraciida - Periplomatidae
 Carditida - Carditidae
 Nuculida - Nuculidae
Acila picturata divaricate nutclam
 Nuculanida - Malletiidae
 Nuculanida - Sareptidae
Portlandia sp. Mörch 1857 clam