ABSTRACT

As one of the steps that lead to understanding limestone formation, the geochemical behavior of chemical species during limestone formation from corals was discussed by calculating values of concentration factors for chemical species between limestones and corals. During the limestone formation, iron, silicon, aluminum, manganese and phosphorus are enriched in limestones, while sodium, chloride and sulfate ions are removed to river waters from corals. Aluminum seems to be the least mobile element in the processes. The chemical composition of river waters in the limestone areas of the Ryukyu Islands is interpreted to be a result of addition of sulfate, sodium, calcium and bicarbonate from corals and limestones through dissolution and of supply of chloride and sodium from dry fallout and precipitation of sea salt.