The Shimane peninsular district is a part of the San-in Neogene province situated in the most southwestern marginal region composed of the so-called "Green Tuff".
The work taken by the writer is the study of the pitchstone interbedded with plagioliparite flow and its pyroclustics occured especially in the Shimane peninsular district.
On the basis of the results, the writer wants to describe the petrographical and petrochemical data and thus to discuss the petrological probrems.