秋田県南部-山形県北部油田地帯の深部地質構造  [in Japanese] Subsurface structure under the oil fields in southern Akita and northern Yamagata Prefectures  [in Japanese]

Data of many test wells of the Akita-Yamagata Oil Fields have been published. In these publications, many geological cross sections and panel diagrams of the oil field were reviewed. These subsurface data indicate uniform predominance of basaltic rocks of the Daijima-Nishikurosawa Formation in the oil field, and the estimate thickness of the formation exceed 1500 m. These facts suggest that the basaltic rock played an important role in the formation of oil field basin. The data also show the development of Kitayuri Thrust fault system which occurs along the coastal region of the Japan Sea. The fault system is 200 km in total length and 15 km in width. Most of the displacement of the faults has been presumably achieved since the Tentokuji age and the faults are still active at present.