Distribution of opal phytoliths in shore zone of several region in Japan

Abstract

Phytoliths originating from major Japanese coastal plants were investigated at six survey areas. Correlation between the phytolith's concentration or density in surface sediments was studied. In addition, relationships among the numbers of phytoliths, their grain size, and sediment grain size were studied at the Obitsu River estuary, Tokyo Bay. It was suggested that most of the phytoliths were transported by winds, and were deposited in lower areas or sites along with silt and very fine sand particles, such as salt ponds. Correlation between the density and the coverage and distance from the source suggested that the transportation efficiency or transportability of phytoliths decreased in the following order: “Phragmites australis type,” “Carex pumila type ・ Ischaemum anthephoroides type ・ Calamagrostis epigeios type,” “Leymus mollis type,” “Imperata cylindrica var. koenigii type”.