与那国島の琉球層群にみられる Halimeda 石灰岩の堆積環境

概要

論文の詳細を見る
Halimeda limestone, found in the Pleistocene Ryukyu Group on Yonaguni-jima (Yonaguni Island), is characterized by an aggregated occurrence of segments of the calcareous green alga Halimeda. The limestone also contains tests of benthic foraminifers and limited quantities of other skeletal grains with a micrite matrix. Because the segments of Halimeda are rather broader and thinner, they are comparable with the Caribbean "deep-water Halimeda suite", Shallow water coral limestone generally overlies the Halimeda limestone with a definite boundary, while deep water limestone (rhodolith, Cycloclypeus-Operculina or detrital limestone) gradually grades into the Halimeda limestone. Paleontological and stratigraphical evidence implies that the Halimeda limestone is composed of in-situ segments of Halimeda which inhabited a deep forereef environment at water depths greater than 50m.
日本古生物学会の論文
1990-12-15