山口･下関と長門 ｜ バイクで巡る本州最西端 岩石いっぱい！堆積岩･貫入岩･柱状節理

Shimonoseki and Nagato, at the westernmost tip of Honshu, are a fascinating area where a wide variety of rocks from a wide range of ages can be seen. Most of the Chugoku Mountains are sedimentary rocks, accretionary complexes, and granite dating back over 100 million years, but traces of magma intrusion can be seen in places, and along the Sea of ​​Japan coast, traces of volcanic activity from the period of the Sea of ​​Japan opening can be seen. From Bisha-no-hana, at the westernmost tip of Honshu, to Omijima, a rapidly eroding caldera somma, we'll take a motorcycle tour of the topography and geology. Geological map source: Geological Survey of Japan, AIST, "1:200,000 Seamless Geological Map of Japan v2" https://gbank.gsj.jp/seamless/v2/viewer/