東北日本弧,那須火山群,南月山火山の岩石学的モデル(<特集>火山のモデル(II))
スポンサーリンク
概要
- 論文の詳細を見る
Nasu volcanoes, the southern part of the volcanic front of Northeast Japan arc, comprises 10 small volcanic centers. Minamigassan is one of these centers and is located at the southern end of this volcanoes. A petrological model of magmatic proccess of Minamigassan volcano is presented based on the mineralogy and whole-rock chemistry. The eruption products of Minamigassan volcano can be divided into five units ; E-1, E-2, L-1, L-2, and L-3 units from lower to upper. The caldera collapse occured at the beginning of L-1 unit. The E-1 unit belongs to medium-K tholeiite, E-2 to low-K tholeiite, L-1 to medium-K calc-alkaline, L-2 to medium-K tholeiite, and L-3 to medium-K calc-alkaline categories, respectively. L-1 unit is petrologically similar to E-1 unit. Least squares subtraction calculation for major elements and Rayliegh fractionation model calculation for trace elements indicate that the chemical variation within E-1 and E-2 unit can be interpreted by fractional crystallization of phenocrystic minerals. On the other hand calc-alkaline suites, L-1 and L-3 units suffered magma mixing. These units formed by mixing between basic magma which resembles E-1 unit magma and felsic magma which is derived from early stage magma through crustal contamination or crustal melt. Distinct differences in LIL/HFS ratio among E-1 and E-2 units cannot be explained either by the difference in degrees of partial melting of a common source or by any fractional crystallization process. The difference between E-1 and E-2 units have been originated in chemical difference of source material.
- 特定非営利活動法人日本火山学会の論文
- 1991-07-15
著者
関連論文
- 中新世後期-鮮新世前期に形成された, 仙台市北西部の黒鼻山玄武岩
- 仙台市, 黒鼻山玄武岩の層準 -後期中新世-前期鮮新世に噴出したピジョン輝石玄武岩-
- B16 仙台市, 黒鼻山玄武岩の層準 : 後期中新世∿前期鮮新世に噴出したピジョン輝石斑晶を含む玄武岩
- 鳥海山の完新世噴火史と火山災害 (総特集 活火山における噴火様式の時代的変遷と長期噴火予測(上))
- 蔵王火山,東麓に分布するテフラについて : Za-To 1-4の年代及び噴出量
- A08 東北日本弧,1888-1900年に起こった,水蒸気爆発による低温火砕サージの特徴(火山の地質・形成史(1),日本火山学会2006年秋季大会)
- 由布-鶴見地溝帯内, 鬼箕単成火山の非島弧的な地質学的, 岩石学的特徴
- P17 九州、由布・鶴見地構内の鬼箕単成火山について
- 蔵王火山および白鷹火山の巨大山体崩壊発生時期
- 東北日本, 火山フロント付近の 2.O Ma 以降の火山活動とテクトニクスの推移