Shallow-marine ostracode faunas around the Eocene/Oligocene boundary in the northwestern Kyushu, southwestern Japan
Article first published online: 23 JUL 2007
Volume 40, Issue 3, pages 293–303, September 2007
How to Cite
YAMAGUCHI, T. and KAMIYA, T. (2007), Shallow-marine ostracode faunas around the Eocene/Oligocene boundary in the northwestern Kyushu, southwestern Japan. Lethaia, 40: 293–303. doi: 10.1111/j.1502-3931.2007.00028.x
- Issue published online: 23 JUL 2007
- Article first published online: 23 JUL 2007
- Manuscript received on 22/03/2006; manuscript accepted on 17/05/2007.
- E/O boundary;
- Oi1 event;
Middle Eocene–early Oligocene ostracode faunal changes in northwestern Kyushu of southwestern Japan are identified in this study. Ostracodes occur from shelf deposits of five formations: the middle Eocene Okinoshima, the upper Eocene Funazu, the uppermost Eocene–lowermost Oligocene Kishima, the lowermost Oligocene Itanoura, and the lower Oligocene Waita Formations. The middle Eocene–earliest Oligocene ostracodes were characterized by warm-water genera, indicating tropical, subtropical and Tethyan genera, whereas the late early Oligocene ostracodes do not include warm-water taxa, consisting of temperate realm genera. The middle Eocene–earliest Oligocene ostracodes do not include remarkable changes of species composition, in contract with equatorial Pacific radiolarians and West Coast USA molluscs. Ostracodes suggest that distinct climatic cooling did not occur in the southwestern Japan during the middle Eocene–earliest Oligocene.