Petrological Model of Crustal to Upper-mantle Structure, NE Honshu arc, Japan

分析了来自Ichinomegata火山的下地壳和上地幔包体的化学成分，并在高压下测量了地震速度。与最近获得的东北本州弧的地震速度结构进行了对比，得到了日本本州弧下地壳和上地幔的新的岩石学模型。结果表明，由于下地壳的平均化学成分是由角闪辉长岩组成的，下地壳的平均化学成分比以前估计的要基础得多。第四纪火山岩的地球化学研究表明，如果它们是由含有下地壳物质的角闪石的部分熔体组成的，那么就有可能产生低K拉斑玄武岩。现提交一篇关于花岗岩侵位模式的论文。我们研制了一套岩石复合磁组构测量系统，并将其应用于北上山地的戈约花岗岩。戈约花岗岩中部分滞后剩磁各向异性所揭示的多重磁组构代表了花岗岩体演化过程中的离散运动学事件。地震实验表明，大型崩塌火山口下的岩浆储集层以熔岩的形式存在。通过对地震速度资料和地壳岩石学模型的对比，建立了日本本州岛东北弧区与岩浆管道系统有关的地壳结构演化模型，并对其进行了初步检验。目前该研究的许多成果已全文发表，其他一些新成果已在多个期刊上提交或正在筹备发表中。

The chemical compositions of lower crustal and upper mantle derived xenolith from Ichinomegata volcano were analyzed, and the seismic velocities were measured under high pressures. The data was compared with a seismic velocity structure of NE Honshu arc which obtained recently, and obtained a new petrological model of lower crust and upper mantle in NE Honshu arc, Japan.The results clarified that the average chemical composition of the lower crust is much more basic than estimated before, because they were composed from amphibole gabbro.The geochemical study of the Quaternary volcanic rocks was showed that there was a possibility of low-K tholeiites were they were composed from partial melts of such amphibole bearing lower crustal materials.A paper conceming the emplacement model of granitic rocks was submitted now. We have developed a measuring system of composite magnetic fabric of rocks, and applied it to the Goyo granite from Kitakami mountainland. The resulted multiple magnetic fabric reveled by anisotropy of partial anhysteretic remanent magnetization in the Goyo granite represents discrete kinematic events during evolution of the granitic body.It was clarified by seismic experiments that the magma reservoirs under large-scale collapse calderas show laccolith in its form. The comparison of seismic velocity data and the petrological models of crustal layer have done, and a new evolutional model of crustal structures related magma plumbing system was established and presicely examined in NE Honshu arc, Japan.Many of the current results of this research were published as full papers, and other new results were submitted by several journals or under the preparation for publish.