The outcrop in Chiba Prefecture has been nominated for a Global Boundary Stratotype Section and Point (GSSP)
- “Chibanian” may be listed on the geological time scale -
Summary of AIST Press Release on June 7, 2017
An academic team has submitted the application for registration of “Chiba section” as a GSSP to the commission of IUGS (International Union of Geological Sciences). The team is composed of 32 earthscientists from 22 universities and institutions including Ibaraki University, the National Institute of Polar Research, Chiba University, the National Museum of Nature and Science, and the Geological Survey of Japan (GSJ). From GSJ, Takuya Itaki (Marine Geology Research Group) and Osamu Ishizuka (Volcanic Activity Research Group) join the team.
The Chiba section, exposed on a cliff along the Yoro River, Ichihara City, well illustrates the boundary between the Early and Middle Pleistocene (770,000 years ago), when the last geomagnetic field reversal occurred. Two other candidates in Italy, the Montalbano Jonico and Valle di Manche sections, are also to be nominated for the GSSP of the boundary. If the Chiba section is approved as the GSSP by IUGS, it will be the first GSSP in Japan and “Chibanian” will be used for the geological age from 770,000 to 126,000 years ago.
The boundary between the Early and Middle Pleistocene in the Chiba section