The thrust which marks accretionary prism (the reverse fault which is low-angle) can be observed on a wave cut shelf of the On-zaki Point south side on. A wave cut shelf is the strong power by movement of the large-scale thrust, and a stratum is destroyed surf zone. When the accretionary prism out of which a foundation in Kii Peninsula is formed is made with depression of oceanic plate, it’s surf zone of the Matsune Hirai thrust which could be done.
When alternation of sandstone and mudstone of the Muro Group which accumulated in former trench was accretionary prism by depression of oceanic plate, this fold was formed. Before hardening perfectly, a sandstone layer was forced on the land side and folded. The top and the bottom becomes inverted as the whole for a stratum. It’s also adopted as a textbook of science of a junior high school as a famous fold worldwide.
A magma penetrates into the Muro Group of accretionary prism which accomplishes a foundation in Kii Peninsula, and it’s a formed fire rock crushing dike. A magma can observe the state which entered into reticulation in a crack of a stratum and the rock by which the surrounding stratum was taken in a magma (capture rock). A hot spring from Susami Town to Shirahama Town is distributed along this dike.
An old wave cut shelf rises in Esuzaki Island, and the topography which became a coastal terrace is the feature. Sandstone and alternation of sandstone and mudstone of the Muro Group which is the accretionary prism out of which a foundation in Kii Peninsula is formed can be observed. All island takes on the aspect in a wildwood as a shrine grove of Kasuga-jinja Shrine, a warm place, it’s rich in the kind of plants.