水田土壌中の灰白色炭酸鉄結核について On the siderite concretion in paddy soils
A grayish white concretion was taken from the G horizon of a paddy soil developed on the Abe river plain. It was examined by physical and chemical analyses, D. T. A. and X-ray diffraction. From the results obtained, it was concluded that the sample was dominated by siderite (FeCO_3). The sample was crushed and divided into 2 fractions. One fraction was added in water and kept in the constant temperature (28℃), and another kept in room temperature under dry condition. After 35 days, each fraction was again examined by X. R. D. and D. T. A.. It was seen that much more goethite (Fe_2O_3・H_2O) was formed from siderite under the wet condition, but little under the dry condition.
ペドロジスト 3(2), 53-58, 1959