伊豆, 下賀茂温泉水の起源

概要

論文の詳細を見る
The geothermal brines (Surface temp. =100℃) discharged from drillholes (52∿250m in depth) at Shimogamo, Shizuoka, Japan, have been analyzed for stable isotopes of hydrogen, oxygen, and sulphur, together with chemical analyses. The chemical and isotopic evidences indicate that the geothermal brines are the mixture of local superficial water and the deep geothermal brine supplied by a single source. The estimated chemical and isotopic composition of the deep geothermal brine are interpreted by a mechanism, in which sea water penetrates into the deep geothermal brine reservoir and changes into Na-Ca-Cl brine through hydrothermal reactions with surrounding rocks. The underground temperature of the deep geothermal brine has been estimated as 221°∿335℃ from the oxygen isotopic fractionation between sulphate ion and water in the brine.
1972-12-01