Where: Japan (32.9° N, 129.6° E: paleocoordinates 38.1° N, 124.0° E)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Okinoshima Formation, Bartonian (41.3 - 38.0 Ma)
• STRATIGRAPHIC RELATIONS: From the Okinoshima Fm, which conformably overlies the Hashima Fm and is unconformably overlain by the Iojima Fm. AGE: Late Eocene according to foraminiferal biostratigraphy in Asano (1958), and correlated to the Sakasegawa Shale. Kobayashi and Kamada (1959) suggest that the formation could even range from Middle-Late Eocene. 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). STRATIGRAPHIC POSITION: From bed of unknown thickness within 150 m thick formation.
• bed-level stratigraphic resolution
Environment/lithology: offshore; lithified siliciclastic sediments
Size class: macrofossils
Preservation: cast, mold/impression
Collected by Kamada
Collection methods: surface (in situ),
• COLLECTOR: Y. Kamada and graduates students Nagasaki University, c. 1950's. REPOSITORY: Nagasaki and Tokyo University.
Primary reference: T. Kobayashi and Y. Kamada. 1959. An Eocene Nautiloid from Kyushu, Japan. Japanese Journal of Geology and Geography 30:105-125 [A. Hendy/A. Hendy]more details
Purpose of describing collection: paleoecologic analysis
PaleoDB collection 81227: authorized by Austin Hendy, entered by Austin Hendy on 11.06.2008
Creative Commons license: CC BY (attribution)