竜神付加体の枕状溶岩がみられます。枕状溶岩は遠洋の海底火山でできて海洋プレートに乗って移動してきたものです。海洋プレートの沈み込みに伴って枕状溶岩の岩体は破断して、泥岩層と混在しています。北山峡の筏流しの難所のひとつで、家督を継ぐ長男は筏に乗せず弟を乗せたのが地名の由来とされます。

Pillow lava of the Ryujin accretionary prism can be seen. Pillow lava is made of pelagic submarine volcanoes and travels on oceanic plates. As the oceanic crust subducts, the pillow lava body breaks and mixes with the mudstone layer. It is one of the difficult points of the raft drifting in the Kitayama Gorge, and it is said that the place name is derived from the fact that the eldest son who succeeded the family reign did not put the raft on the raft but put his younger brother on it.

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うえもり　う 2022/01/20(Thu) 17:11 No.146