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2021 Vol.130 No.5

The Tetori Group Exposed at Yunotani, Upstream on the Tedori River in Southwestern Mt. Hakusan

The Tetori Group is the thickest succession of Mesozoic terrestrial strata in Japan. The middle to upper parts of the Tetori Group crop out at the south side of Mt. Hakusan. The lateral variation of facies in formations of the Tetori Group led to complex naming, which has now been rationalized to reflect a coherent understanding of the Tetori Group architecture. The photograph shows the Kuwajima Formation, taken from the southeast, where it consists of northwest dipping, alternating beds of sandstone and mudstone, overlain by the sandstone of the Amagodani Formation. These strata dip along the ridge to lower elevations than at this location, where sandstone of the Otaniyama Formation, which underlies the Kuwajima Formation, is exposed. This sequence can be traced to the type section of the Tetori Group in the Shokawa area. The location of this photograph is Yunotani, located upstream on the Tedori River, Shiramine District.

(Photograph: Kazuto KOARAI, Photographed on July 22, 2004;
Explanation: Masaki MATSUKAWA)