抄録
The author disscussed here the relationship of the sureface movement of Hiebara district in Izumo city, Shimane Prefecture and the crystallization of alunogen (Al2 (SO4) 3-18H20).
The results of examination on the cause of the surface movement, showed that it is due to the alunogencrystallized from the ascending acidic groundwater (pH about 2) along the hydrothermal alteration zone composedof illite, illite-montrillonite mixed layer mineral, kaoline, quartz and pyrite.
