Particle Size Distribution, Chemical Composition and Calculation of Standard Mineralogical Composition of Suspended Sediment Transported by a Stream in Okinawa Island

Abstract

The suspended sediment delivered by the Makiminato stream during a flood period consists of about 40 percent clay, 58 percent silt and 2 percent sand in terms of weight. The chemical composition of the sediment is more analogous to that of terrigenous clay than red clay and nearshore marine clay. In comparison to the terrigenous clay, it is relatively low in SiO2 and significantly high in CaO which is traceable to the calcareous fossils within the Shimajiri formation and the Ryukyu limestones accumulated from place to place along the formation.
The mineral composition of the sediment is calculated by recasting the chemical oxide components into standard minerals plagioclase, K-feldspar, Ca-feldspar, calcite, dolomite, enstatite, anhydrite, chlorite, montmorillonite, kaolinite, illite, ilmenite, quartz and hematite.