Keywords:formation of sea of japan, facies analysis, Miocene
The Japanese archipelago was previously part of the Asian Continent, and was separated from the continent by back-arc rifting that occurred on the eastern edge of the continent. Traces of various volcanic activities and sedimentation processes involved in this dynamic tectonic event were left across a wide area along the Sea of Japan coast of the Japanese archipelago. While many traces of activities in the sea are found in northeastern Japan, The San’in Kaigan UGGp has traces of the tectonic history of this area, changing from solid land through partial sea to shallow sea. Strata, fossils, volcanic rocks, and other features related to the traces are designated as geosites in the San’in Kaigan UGGp. Although ongoing rifting in various places on the earth is a tectonic event causing the formation of island arcs and epicontinental seas, its mechanism is still under discussion. We research evidence of rifting and the formation of the Sea of Japan in the San’in Kaigan UGGp area. In this session, we will discuss about reconstruction of two types of Miocene volcanoes in the northern part of hyogo, San’in Kaigan Geopark, based on facies analysis.