Alteration of 2:1-type Clay Minerals in a Gray Lowland Soil Derived from Permian Sediments in Takahama Cho, Fukui Prefecture
1997 年 41 巻 1 号 p. 23-31
詳細
1997 年 41 巻 1 号 p. 23-31
The bio-hydrologic alteration of 2:1-type clay minerals in a Gray Lowland soil derived from Permian sediments was discussed, making the comparision between difference of these minerals in the sand fraction and clay one, by means of XRD method, DTA, TG and IR spectrometry. The result is summarized as follows: 2:1-type clay minerals should release iron from their interlayer position and silicate layer lattice as resulting in the seasonally reductive condition with vertical movement of grand water in soil horizon. Chlorite and mica minerals altered partially to chlorite-vermiculite intergrade and vermiculite, in a Gray Lowland soil derived from the Permian sediments classified into the Early Ana-diagenesis, respectively. Previous study also indicated such alteration of 2:1-type clay minerals. These results were reverse to the formation of chlorite from vermiculite at the topsoils of two excessively drained Brown Lowland soils in Ogawa Machi, Saitama Prefecture reported by Mitsuchi (1967). This difference should be caused by the hydrologic condition between two soils.
