Hiryu Falls and Columnar Joints

Hiryu Falls (Hiryunotaki) is the largest waterfall in Kanagawa Prefecture, separating into two tiers with the upper tier at 15 meters and the lower at 25 meters. The lava forming this waterfall is andesite from the early central cone. Along the course to Hiryu Falls, are horizontally extending columnar joints (Among the cracks (joints) formed when lava cools and solidifies, are those that develop regularly in columnar shapes and are formed perpendicular to the bottom or top surface of the lava, and have a hexagonal cross-section.) that can be observed up close.

Columnar joints seen along the course to Hiryu Falls

In the same way as columnar joints, there are plate joints in the shape of cracks that are formed as lava cools and solidifies. At the bottom of Hiryu Falls, there are areas where plate joints have developed. The plate joints that develop in parallel to the base of the lava are sometimes used as stone materials for stone monuments because of their shape.

Plate Joint Stone Monument (Odawara, Terayama Jinja (Terayama Shrine))