岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

福井県おおい町赤礁崎で見出された非石灰質ビーチロック

Suzuki, Shigeyuki Graduate School of Natural Science and Technology, Okayama University
Azuma, Yoichi 平寺町松岡兼定島 4-1-1 **
Deyama, Yasuyo 平寺町松岡兼定島 4-1-1 **
Yukawa, Hirokazu Fukui Prefectural Dinosaur Museum
Usui, Mayumi Fujigakuin-Okayama
Abstract
Beachrock which was formed about 0.5 meter higher than high tide is found in Akagurisaki, Ohi Town, Fukui Prefecture. The outcrops always get wet by spring water. The sediments are composed of well sorted rounded gravels and sands but calcareous shell is not found at all. Intergranular space is occupied by white amorphous cement. Magnesium and silicon rich composition of the cement is obtained by EPMA analysis. There is a conjecture that the magnesium rich cement was precipitated in spite of solution of calcareous shell under saturated state by spring water, because calcium has a higher tendency to ionize than magnesium.
Keywords
Beachrock
Akagurisaki
non-calcareous cement
ionization tendency
ISSN
1340-7414
NCID
AN10506284