Clay Minerals in the Bottom Sediments from Kagoshima Bay, South Kyushu, Japan.

Abstract

Semi-quantitative analysis of the clay minerals in the bottom sediment samples from Kagoshima Bay was carried out to determine the distribution trends of the clay minerals and its relationship with the geology of the study area as well as certain physico-chemical conditions within the bay. The study utilized various methods such as XRD, DTA, IR and SEM. The clay minerals identified are 10A- halloysite, illite, smectite, kaolinite and chlorite. Non-clay mineral components are feldspar, quartz, cristobalite, gypsum, calcite and pyrite. 10A-halloysite is the most abundant clay mineral. Illite, smectite and kaolinite are the next abundant. Chlorite is the least common. Non-clay are also widely distributed in the sediments of Kagoshima bay. Feldspar, quartz, cristobalite and pyrite are common throughout the bay while calcite and gypsum vary in distribution. Based on the geology of the surrounding area, it has been shown that the terrigenous supply represents the dominant agent responsible for the distribution of the clay minerals. Certain environmental conditions, however are considered minor mechanisms that influence clay mineral distribution. The clay minerals were transported with feldspar, quartz and cristobalite.