1988 年 97 巻 3 号 p. 172-177
Neogene volcanogenic sedimentary rocks such as tuffaceous silt stone or silt stone in which fine grained pyrite (probably of biogenic) is commonly observed are easily reacted with water solution (distilled water, NaCl-bearing water, SrCl2 ·6H2O-, CsCl-, Co (OH) 2-, Sr (OH) 2·8H2O- and Co (OH) 2- bearing waters) to form gypsum, celestite, kieserite, bieberite, holotrichite, moorhousite, thenardite, mirabilite and other kinds of sulphate, carbonate and chloride minerals.
This interactions between rocks and water solutions should be deeply considered when we are going to keep the so-called Low Lovel Radioactive Waste at relatively shallower part of the earth, because radioactive clement-bearing minerals formed at the earth surface of repositories by the interaction between radioactive waste and groundwater and evaporation would be easily entered into ECOCYCLE even if the repository areas are tightly encircled by the fence made of barbed wire.