著者

杉浦 孜 杉崎 隆一 水谷 義彦 日下部 実

出版者

特定非営利活動法人日本火山学会

雑誌

火山. 第2集 (ISSN:04534360)

巻号頁・発行日

vol.25, no.4, pp.231-244, 1980-12-01

被引用文献数

2

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Ontake Volcano suddenly began to erupt on its south-western flank near the summit at 05^h20^m on Oct, 28, 1979, forming several new craters and ejecting large amounts of volcanic ash and steam. Up to that time, the volcano had been believed to be dormant, though there were weak geothermal activities at a part of the south-western flank of the volcano, Jigokudani. This paper reports some results obtained by preliminary examination of volcanic ashes, thermal waters and gases collected on and around Ontake Volcano during the early stage of eruptive activity. The volcanic ashes are homogeneous in chemical and mineralogical compositions, and similar in chemical composition to the pre-historic volcanic ashes. The ashes contain pyrite, anhydrite, cristobalite and clay minerals. The sulfur isotopic equilibrium temperature is estimated to be about 400℃ for pyrite-anhydrite pairs in the volcanic ashes. The estimated temperature is apparently too high for the temperature of phreatic explosion. The interpretation of this isotopic data remains unsettled. The thermal waters collected from the boiling pools in craters are enriched in D and 19^<O>. The isotopic enrichment is probably caused by evaporation of water at the surface of boiling pool. The hydrogen and oxygen isotopic data also suggest that spring waters issuing around Ontake Volcano are meteoric in origin. Nigorigo Hot Spring, about 4 km north-west of Ontake Volcano, showed significant increases in the concentrations of major dissolved chemical components soon after the eruption, but since then no significant change in chemical and isotopic composition has been observed

著者

杉崎 隆一 杉浦 孜 水谷 義彦 日下部 実

出版者

特定非営利活動法人日本火山学会

雑誌

火山. 第2集 (ISSN:04534360)

巻号頁・発行日

vol.25, no.2, pp.107-108, 1980-07-01

著者

鈴木 重人 伊藤 正裕 杉浦 孜

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.71, no.7, pp.183-192, 1976-07-05 (Released:2008-08-07)

参考文献数

3

被引用文献数

3

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本鉱物は,三波川帯中の各種銅鉱物をともなう蛇紋岩体の割れ目より発見された。細かな針状ないし長柱状をなし,特徴的なsky-blueの色を呈する。構造式(C=1)として, Mn0.019Ni0.231Cu7.770(SO4)3.904(CO3)(OH)6.232・48.4H2O または, (Mn,Ni,Cu)8(SO4)4(CO3)(OH)6・48H2Oをもつ。 本鉱物の光学的性質, X線回折,電子線回折, DTA-TG, IRパターンに見られる諸性質について報告した。また,産状の違いにより, X線回折およびDTAパターンに僅かな違いが見られ,これらについても検討した。 Nakauri, Shinshiro, Aichi Prefecture愛知県新城市中宇利

著者

杉崎 隆一 杉浦 孜

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.39, no.1, pp.99-109, 1986-03-25 (Released:2010-11-17)

参考文献数

31

被引用文献数

1

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Remarkable anomalies in gas compositions were observed at a fumarole and three mineral springs before the Western Nagano Prefecture Earthquake, 1984. The epicentral distance are 9 km for the fumarole and 50 km, 71 km and 95 km for the springs, respectively. Deep seated gas emission induced by the compressive stress of the earth tide had been observed previously at the two mineral springs as the monitoring stations and at a lava lake in Hawaii. It is analogically inferred that the gas anomaly before the earthquake can be attributed to the variation in the emission rate of deep seated gas resulting from changes in pore pressure and magma-reservior volume, which are subjected to the tectonic stress that caused the earthquake. Another aspect is emissions of H2 gas at three mineral springs and gases from different sources at one spring. These indicate the formation of new cracks near monitoring stations and the permeation of groundwater into the cracks. The mechanical processes inferred from the present geochemical observation are compatible with those described by geophysical models based on fracturing experiments.