山形および米沢盆地における後期中新世噴火活動 : とくに陥没をともなう噴火活動について

概要

論文の詳細を見る
In late Miocene, violent acid volcanic activities took place in the Yamagata and Yonezawa basins. Characteristic feature of the volcanic activities are to follow depression. At the platform area along the uplift of the backborne range, several depression basins were formed on the structural zone having NS direction ascribed to intersection of fractures of NNW-SSE and NNE-SSW directions. Volcanic activities took place in such depression basins. Volcanic activities are divided into following two types; 1. Type I (Akayu type volcanic activity): Depression - talus deposition - deposition of volcanic materials - migration of basin - formation of double grading. 2. Type II (Itaya type volcanic activity): Depression - talus deposition - deposition of volcanic materials - eruption on land.
日本地質学会の論文
1973-07-01