Earth history is divided into 115 geological ages based on the age of rock formation and the transition of biological fossils.GSSP is certified to standardize this period.It can be said that it is the best stratum on the earth for observing and studying the boundaries of the geological age.

　The Chiba section applied for this time shows about 77 years ago when the earth's magnetic field was last reversed.At the boundary between the early and middle Pleistocene, the GSSP has not yet been decided.

　Research on the Chiba section has been conducted for the past 70 years, but it was published mainly in Japanese, so it could not be read by overseas researchers.Therefore, the research group first published a review paper summarizing the research results of its predecessors in an international academic journal.In addition, the age of the geomagnetic reversal recorded in the Chiba section is determined with high accuracy, and the marine environment changes at that time are restored with higher resolution, and the conditions necessary for applying for GSSP are cleared at a high level. Clarified that.

　Two geological formations in southern Italy are also listed as candidates for the GSSP on the boundary between the early and middle Pleistocene, and will be decided as one after examinations such as multiple votes.If the Chiba section is selected, it will be Japan's first GSSP, and the Japanese place name will be used for the first time as a geological time name.

　It will be interesting to see if the thoughts of successive stakeholders, including 22 people from 32 institutions such as Ibaraki University, National Institute of Polar Research, Chiba University, and the National Museum of Nature and Science, who were involved in the application, will bear fruit.