The Nishihiro Formation cropping out the Nishihiro at the Hirokawa area, Wakayama Prefecture, is characterized by the predominance of white feldspathic and/or quartz arenite. lt yields brackish-water pelecypods (Tethyan fauna) and gastropods, together with plant remains. Among the identified species, Aguilerella cf. nagatoensis, Eomiodon matsumotoi, Hayamina carinata, and Tetoria cf. yoshimoensis are common or diagnostic. From the faunal aspects and lithological characters, the formation especially resembles the Yamabu Formation of the Haidateyama area, the kawaguchi Formation of the Yatsushiro area, the Yoshimo Formation of the Shimonoseki area, the Birafu Formation of the Monobe area and the Matsuo Group of the Toba area, and can be correlated approximately with the Valanginian to Hauterivian. Lithic, faunal data and geologic age of the Nishihiro Formation indicate that the upper member of the Ikenoue Formation corresponds to marine in origin which constitute a part of the Nishihiro Formation.
雑誌名
熊本大学教育学部紀要 自然科学
巻
52
ページ
103 - 112
発行年
2003-11-28
ISSN
0454-6148
フォーマット
application/pdf
形態
1399544 bytes
著者版フラグ
publisher
日本十進分類法
457
216
その他の言語のタイトル
Molluscan Fossils from the Lower Cretaceous Nishihiro Formation in the Hirokawa Area, Wakayama Prefecture, SW Japan