房州石＜千葉県＞ 【日本銘石】

Boshu Stone

房州石

Mount Nokogiri was once a quarry that contributed to the development of the Kanto region.
Its history dates back to the Kofun period. The mountain from which the stones were extracted resembled the jagged teeth of a saw, hence the name Mount Nokogiri. Volcanic ash, a by-product of magma from a volcano that erupted millions of years ago, accumulated on the seabed over a long period of time, forming a large bedrock layer in the central and southern part of the Boso Peninsula. It is characterized by black scoria stripes in the white sandstone layer. Among these, the pale pink ones are called sakurame and are considered valuable. Mount Nokogiri, which was carved into the rock face in 1960, is a famous tourist destination, but mining of Boshu stone is currently prohibited. Boshu stone, which is extracted from a stratum dating back 2 million years to the Pliocene period of the Cenozoic Era, contains fossilized shells.