'Chibanian' stratum to be natural monument in Japan
Jiji -- Jun 16
The Cultural Affairs Council recommended on Friday that a stratum in Chiba Prefecture, eastern Japan, be designated as a natural monument, citing its significance as a representing observation point for the beginning of a geological period that could be called "Chibanian."

The stratum along the Yoro River in the city of Ichihara shows traces of a reversal in the Earth's magnetic field. Analysis of volcanic ash indicates that it was formed 770,000 years ago.

The advisory body for the culture minister pointed out that the layer, not far from Tokyo, is easy to observe and extremely valuable academically.

The designation will be made as proposed shortly.

Last year, a Japanese research team applied to the International Union of Geological Sciences for recognition of the stratum as a point representing a shift in geological time.

「チバニアン」の地層が国の天然記念物に指定される。 五稜郭や金閣寺などが名を連ねる国の“文化財”に新たに指定される見通しの「史跡」「名勝」「天然記念物」などが発表された。天然記念物には「チバニアン」の名でも有名な千葉県市原市の地層が。
News sources: Jiji, ANNnewsCH