岩手火山山頂の噴気の化学成分

抄録

At the bottom of the crater and the slope of the central cone Myokogatake of Mt. Iwate many fumaroles are found, from which an enormous amount of volcanic gases containing H₂O, H₂S, SO₂, CO₂, HCl, HF, HBr etc. flow out. The authors examined those fumarole gases on July 27 and September 29～30, 1960. We found sublimates of alunogen, halotrichite, sulfur etc. at such fumaroles that show the temperature near to 100℃ and ammonium chloride at the fumaroles showing 144～205℃. As to the chemical compositions of ammonium chloride, condensed waters and fumarole gases, the following results were obtained : 1) Ammonium chloride No.1. Temp. 205℃, NH₄ 33.5, Cl 65.9, SO₄ 0.0, Br 0.15, B 0.000 (wt. %) (Theoretical value: NH₄ 33.7, Cl 66.3) No.2. Temp. 183℃, NH₄ 33.4, Cl 66.1, SO₄ 0.0, Br 0.21, I 0.0003, B 0.000 (wt. %) No.3. Temp. 144℃, NH₄ 33.6, Cl 66.3, SO₄ 0.0, Br 0.14, I 0.0003, B 0.000 (wt. %) 2) Condensed water . No.2. Temp. 183℃, pH 1.4, H₂S 104, SO₂ 143, SO₄ 5.4, Cl 2876, Br 1.0, I 1.8, B 0.0, Na 2.38, K 0.16, NH_4 16.2, Fe 0.10 (mg/l.) No.3. Temp. 144℃, pH 1.8, H₂S 241. SO₂ 297, SO₄ 1.0. Cl 784, Br 0.2, I 0.3, B 0.0, Na 6.21, K 0.43, NH₄ 18.4 (mg/l.) 3) Fumarole gas No.2. Temp. 183℃, H₂O 98.3, CO₂ 1.46, H₂S 0.109, SO₂ 0.0817, HCl 0.0376, NH₄Cl 0.00181 (vol. %) No.3 Temp 144℃ H₂O 98.2, CO₂ 1.84, H₂S 0.117, SO₂ 0.152, HCl 0.0185, NH₄Cl 0.00167 (vol. %) The temperature above mentioned was measured at the orifice of fumaroles.