The Unzen Volcanic Area Geopark is located in the southern region of Kyushu’s Nagasaki Prefecture on the western end of Japan. The Geopark is limited by the administrative district of the three cities (Shimabara, Unzen and Minamishimabara), almost the same area as the Shimabara Peninsula. The area is located approximately 900km, or four hours by air and bus, from Tokyo, and approximately 100km, or three hours by car, from Kyushu’s largest city, Fukuoka.
Shimabara Peninsula is known for a number archaeological sites, such as Unzen City’s Hyakkadai remains from the Paleolithic Age and Shimabara City’s Onobaru and Obarushimo remains and Minamishimabara City’s Harayama and Gongenwaki remains from the Jomon Period (BC10,000 - BC4C). In particular, remains from the latter part of the Jomon period, such as Yamanotera remains and Gongenwaki remains of Minamishimabara City, clearly point to an advanced cultural life, suggesting the emergence of rice farming before the Yayoi Period (BC4C - AD3C).
Earth Sciences in Shimabara Peninsula
Before Unzen volcano have been developed, an area of Shimabara Peninsula was shallow sea. The strata deposited in this shallow sea is called by "Kuchinotsu Group". Visitors can be observed them in the south of the peninsula. While "Kuchinotsu Group" had been generating, volcanic activities was also occurred in situ. Now gently slope remains observed in southern area is formed by these eruptions;e.g. mainly low-viscous basaltic lava flows. In the center of the peninsula, Unzen volcano situated and many lava dome have been generating by viscous dacite magma.
Techtonics around Shimabara Peninsula
The narrow region extending from near Beppu City to Shimabara Peninsula is characterized by abundant normal and strike slip faults roughly trending EW to NE-SW. This region was proposed as the Beppu-Shimabara Graben. Unzen is a volcano that has developed within one of these active basins (Unzen Graben).
Fueatures of Unzen Volcanic Area Geopark
5 features of Unzen Volcanic Area Geopark are as follows: