著者
田中 均 高橋 努 田代 正之 加登住 誠 本多 栄喜 一瀬 めぐみ
出版者
熊本大学
雑誌
熊本大学教育学部紀要. 自然科学 (ISSN:04546148)
巻号頁・発行日
vol.57, pp.7-17, 2008-12-19

The Miyaji Formation typically exposed along the coast of the Futami area, Kumamoto Prefecture, is characterized by sandy facies in the lower part and muddy facies in the upper. Abundant shallow marine bivalves are usually developed in the several horizons of the lower part. Among the identified species, Pterotrigonia (Pterotrigonia) pocilliformis, Goshoraia minor, Anthonya monobenses are the most diagnostic. From the bivalves faunal aspects and lithological character, the formation is comparable to that of the Lower Hibihana Formation of the Monobegawa Group in Shikokku. Detailed geologic survey has led to the discovery of the Miyaji Formation except for the type locality. The distribution of the Miyaji Formation offers the key to an understanding of the structural movements in this region. The Miyaji Formation is cut by several NW-SE faults. Judging from the field evidence, these faults can be determined to be associated with the geological structure of the Amakusa Islands