著者
大槻 憲四郎 藤巻 宏和 中村 教博 松澤 暢 三浦 哲 山内 常生 松沢 暢 三浦 哲
出版者
東北大学
雑誌
基盤研究(A)
巻号頁・発行日
2006

近い将来に危惧される宮城県沖大地震を予知するため、民間・地方自治体から深度1000m前後のボアホールと温泉を計10カ所前後借用し、遠隔自動受信による「深層地下水観測システム」を構築した。精密な水温・水位・ラドン濃度・炭酸ガス濃度を観測し続け、岩手・宮城内陸地震を含む7個の地震のpre-およびco-seismicな変動を捉えた。
著者
鈴木 五百紀 秋月 瑞彦 長瀬 敏郎 藤巻 宏和
出版者
一般社団法人 日本鉱物科学会
雑誌
岩鉱 (ISSN:09149783)
巻号頁・発行日
vol.90, no.4, pp.124-131, 1995 (Released:2006-12-26)
参考文献数
42
被引用文献数
1 1

Orbicular rock from Inusotoba, Shiroishi, Miyagi Prefecture was studied by optical and chemical methods. The orbicules, which are 5∼20 cm in diameter, are divided into two parts, — core and shell. The core is ball-shaped and dark-colored, and consists mainly of fibrous hornblende and chlorite. The shell, which surrounds core, is light-colored and consists of coarse radial anorthite crystals less than l cm long, which are elongated to a-axis. These radial crystals are characterized by micro subgrains of albite twin and parallel-growing crystals. The other type of orbicule is also known, whose shell consists of several alternate layers of mafic and felsic minerals. This latter type of orbicules is never produced together with the former radial type. The matrix, solidified among orbicules, has a heterogeneous texture, which consists of the dark-part of poikilitic hornblende and the light-part rich in euhedral plagioclase.     The forming environment of orbicular rocks is featured by many close-packed orbicules, the flow structure of felsic mineral assembledge in matrix and unmixing of magma including orbicules with the other magma containing plagioclase spherulites. It is considered that orbicules were formed in supercooling magma possibly due to income of another magma.