The Sulfate Contained in the Blue Gray Sand and Mud Bed (Dainichi Bed) of Lower Tertiary Kakegawa Formation in the Tea Field, Kakegawa City, Shizuoka Prefecture

The chemical properties of the blue gray sand and mud bed (Dainichi bed) in the lower tertiary Kakegawa formation which was exposed by breaking up the surface soil for tea field in Kakegawa city, Shizuoka prefecture were investigated. 1. The reaction of the tea soil derived from the blue gray sand and mud bed was strongly acidic and contained a large quantity of water-soluble acid sulfate, and tea and tobacco seedlings transplanted in the field were entirely died. 2. The most part of the water-soluble sulfate was magnesium sulfate. 3. As the permeability of the soil was decidedly inferior, the water-soluble acid sulfate could not be easily removed by leaching. 4. Amerioration of the physical and chemical properties of the soil is very necessary for tea planting, but it seems very difficult. In a future land development work, a prior detailed geological survey will be needed.