中部地方における温泉水中のホウ素の地球化学的研究(第2報) 信越・房豆帯,四万十帯の温泉水

抄録

The author examined geochemical study of hot spring waters from Shinetsu • Hozu and Shimanto zone on the base of the first report. The derived conclusions are as follows. (1) The frequency distribution of boron is biased to a low content side as first report. In the first report, the most frequent range of boron contents is from 2.1 mg/l to 6.0 mg/l, while, it is from 4.1 mg/l to 12.0 mg/l, in the Shinetsu・Hozu and Shimanto zone. (2) Boron content has positive relationships with water temperature, evaporation residue, sodium, potassium, calcium, chloride ion contents. (3) Evaporation residue, boron, sodium, potassium, calcium, chloride ion contents of some hot spring waters from Shinetsu・Hozu and Shimanto zone are extremely greater than those of Hakusan and Japan North Alps. (4) Except for the hot spring waters fewer than 10 mg/l chloride ion content, minimum and maximum values of B/Cl ratios of the hot spring waters from Shinetsu・Hozu and Shimamto zone are 0.0025 and 0.2332, respectively and the mean value of those is 0.0597. These are greater than those of Hakusan and Japan North Alps. Except for Kashio hot spring, the sources of boron in hot spring waters of Shinetsu・Hozu and Shimanto zone are inferred to be the basement rocks. The sources of boron in Kashio hot spring waters are inferred to be the fossil sea waters.