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
雑誌名
熊本大学教育学部紀要 自然科学
巻
57
ページ
7 - 17
発行年
2008-12-19
書誌レコードID
AN10315071
情報源(ISSN)
04546148
フォーマット
application/pdf
形態
1559152 bytes
著者版フラグ
publisher
日本十進分類法
456.919
その他の言語のタイトル
Cretaceous Miyaji Formation and Its Distribution in the Southwestern Area, Kumamoto Prefecture