西南日本の新生代火成活動とテクト二クス

(1)对日本西南部新生代岩浆活动进行了评述，并对岛弧岩浆活动的成因提出了一些看法。(2)沿着日本西南弧广泛分布着晚新生代玄武岩。在中国区，富集地幔柱与EM I签名上升从地幔深处。另一方面，地幔底辟特征的EM II签名缓慢上升，并夹带上覆N-MORB像北九州地区下面的亏损地幔。(3)东松浦碱性玄武岩（HMB）的岩浆以其三个周期的成分变化（岩浆旋回）而引起人们的关注。研究发现，每个岩浆旋回都是以原始玄武岩喷发为开始，随后是分异玄武岩喷发。这表明HMB的岩浆房是成分分层的。(4)乌库岛的岩石代表了四个岩浆旋回。每一个旋回都以基性岩浆喷发开始，接着是安山质-英安质岩浆喷发。化学变化 ...更多信息 岩石受分异结晶控制，围岩同化作用较小。(5)戴森火山带的类埃达克岩岩浆来源于下地壳部分熔融或幔源岩浆与类埃达克岩岩浆混合。(6)云仙火山的英安岩穹丘在小的时候主要是外生生长，当穹丘变大的时候主要是内生生长，当穹丘变大的时候主要是外生生长，当穹丘变大的时候主要是内生生长，当穹丘变大的时候主要是外生生长，当穹丘变大的时候主要是内生生长。(7)在新生代九州南部，中到高钾的“洪水安山岩”来自高镁安山岩和大量的低钾安山岩的玄武岩岩浆分离结晶。(8)本文描述了日本西南部新生代高镁安山岩的岩石学特征，并讨论了高镁安山岩岩浆的成因。(9)从板块运动的角度解释了古近纪深成作用的机制。(10)采用普通火焰光度法测定低钾，方法简便，精密度高.用该方法对蛇绿岩中的火成、变质角闪石和火山岩中的共生角闪石、单斜辉石进行了K-Ar定年。少

(1) Cenozoic magmatism in southwest Japan was reviewed and some ideas of origin of island arc magmatism were proposed.(2) Late cenozoic basalts are widely distributed along the southwest Japan arc. In the Chugoku district, an enriched mantle plume with an EM I signature ascended from deep in the mantle. On the other hand, mantle diapirs characterized by an EM II signature rose slowly and were entrained an overlying N-MORB like depleted mantle below the north Kyushu district.(3) The magmas of Higashi-Matsuura alkali basalts (HMB) attract attention by their three cyclic variation in composition (magmatic cycles). It has been found that each magmatic cycle starts with the eruption of primitive basalts followed by fractionated ones. This suggests that the magma chambers of HMB were compositionally stratified.(4) The rocks of Uku island represent four magmatic cycles. Each cycle began with the eruption of basic magma, followed by eruption of andesitic to dacitic magma. The chemical variatio … More n of these rocks are controlled by fracitonal crystallization, with minor wall rock assimilation.(5) Adakite-like magmas in Daisen volcanic zone were derived from partial melting of lower crust or mixing of mantle derived magma and adakite-like magma.(6) A dacite dome at Unzen volcano grew mainly exogeneously when it was small and the effusion rate was high, but endogeneously when the dome became large and the effusion rate declined.(7) In Cenozoic southern Kyushu, moderate to high potassic "flood andesites" were derived from high-magnesian andesite and voluminous low potassic andesites were produced by fractional crystallization of basalt magmas.(8) Many high-magnesian andesites (HMA) in Cenozoic southwest Japan were petrographically described and the origin of HMA magmas was discussed.(9) Mechanisms of Cretaceos to Paleogene plutonism were explained by the plate motions.(10) The low potassium analytical method with ordinary flame photometry in convenience and high precision was developed. This method was applied to the K-Ar dating of igneous and metamorphic hornblendes from ophiolites and coexisting hornblende and clinopyroxene from volcanic rocks. Less