JaLCDOI 10.18926/21194
Title Alternative Stable isotope study of the hotsprings and volcanoes of Hokkaido, Japan
FullText URL pitsr_047_055_067.pdf
Author Matsubaya, Osamu| Sakai, Hitoshi| Ueda, Akira| Tsutsumi, Makoto| Kusakabe, Minoru| Sasaki, Akira|
Abstract Stable isotope ratios of hydrogen, oxygen, carbon and sulfur of precipitation, thermal and mineral waters, and volcanic gases were measured. The isotopic data combined with chemical and geological information were discussed in terms of origin and evolution of the hotsprings and volcanic gases. The hotsprings along the Uchiura Bay, Oshima Peninsula are mostly near-neutral NaCl-type thermal water and may be divided into three groups : (1) thermal waters isotopically similar to the precipitation of this area, (2) those similar in D/H to the local meteoric waters but enriched by 2 to 3‰ in (18)O compared to the latter, and (3) those enriched significantly in both D and (18)O relative to the local meteoric waters. The first and second types of thermal water probably form from local meteoric water which percolates through "Green Tuff" formations and acquires dissolved chemicals from them. However, high salt concentration and the oxygen isotope shift (thesecond type) may imply that the NaCl-type water of volcanic origin might be involved. On the other hand, the waters of the third group can be explained by mixing of modern sea water into the second type thermal water (in case of Yachigashira) or by incorporation of fossil sea water of Tertiary origin into modern meteoric water (Nigorigawa). Except for Esan, Noboribetsu and Atosanupuri volcanic systems, waters from all the hotsprings and volcanic fumaroles associated with Quaternary volcanic rocks are meteoric in origin. Thermal waters at Esan, Noboribetsu and Atosanupuri have δD = -30~-50 and δ(18)O = -1~+ 3‰ and are enriched in D and (18)O relative to local meteoric water of the respective area. The origin of these waters and the mechanism (s) controlling the isotope ratios could not be made clear by the present study. Interesting is the finding that at Esan, Noboribetsu and Atosanupuri, thermal waters are enriched in D and (18)O relative to near-by fumarolic gases. The enrichment factor is 18 to 26‰ for hydrogen and 4 to 6‰ for oxygen, implying that more than one stages of liquidvapor separation are taking place in underground hydrothermal systems.
Publication Title 岡山大学温泉研究所報告
Published Date 1978-03-25
Volume volume47
Start Page 55
End Page 67
ISSN 0369-7142
language 日本語
File Version publisher
NAID 40000321119
JaLCDOI 10.18926/21159
Title Alternative An isotope study of hot springs in Nagano Prefecture
FullText URL pitsr_050_017_024.pdf
Author Matsubaya, Osamu| Sakai, Hitoshi| Kusakabe, Minoru| Sasaki, Akira|
Abstract Water samples from 28 hotsprings and mineral springs in Nagano Prefecture, central Japan, were examined for their stable isotope ratios of hydrogen, oxygen, carbon, and sulfur. Spring waters of Kashio are highly saline and enriched in heavy isotopes of oxygen and hydrogen (δ(18)O=-2.5~-4.6‰, δD=-54~-57‰). Linear relationships among δD, δ(18)O, and Cl(-) suggest that spring waters are the mixtures of a deep brine and local surface water. Extrapolation of the linear relationships indicates that the deep brine is both isotopically and chemically very similar to the deep brine previously suggested for the springs of Arima, Takarazuka, and Ishibotoke of which δD, δ(18)O, and Cl(-) are estimated as -33‰, +8.0‰, and 44g/l, respectively. A common origin may be warranted among these postulated brines, while their provenance is yet to be worked out. The hot springs in Matsushiro are a Na-Ca-Cl type of high carbonate content. Their hydrogen and oxygen isotope ratios (δD=-71~-46‰, δ(18)O=-9.1~-2.0‰) are higher than the local surface water. On the basis of the relationships among δD, δ(18)O, and Cl(-), they are considered to be the mixtures of fossil sea water and certain water of meteoric origin of which Cl(-) is about 4g/l and δ(18)O is higher by about 3‰ than the local surface water. The latter may be meteoric water circulating in the marine sedimentary formations (Green Tuff formations) with soluble sea salts. Isotopic exchange with carbonate minerals in the formations explains its (18)O enrichment. Spring waters from Yashio and Isobe (Gunma Pref.) as well as Yunosawa and Yatate (Akita Pref.) were previously interpreted to be mixtures of fossil sea water and local surface water of low Cl(-) content. Re-examination of their data revealed that the meteoric waters responsible for these springs contain about 3g/l Cl(-), similar to the value obtained for Matsushiro. However, unlike Matsushiro, the meteoric waters in these areas are found to be isotopically similar to the local surface waters. Waters from other hot springs studied here are of simply meteoric origin, thus belonging to the GreenTuff type water previously defined.
Publication Title 岡山大学温泉研究所報告
Published Date 1980-03-25
Volume volume50
Start Page 17
End Page 24
ISSN 0369-7142
language 日本語
File Version publisher
NAID 120002310953