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

分析了一目方火山下地壳和上地幔捕虏体的化学成分，测量了高压下的地震速度。与新近获得的日本本州东北弧地震速度结构进行了对比，得到了一个新的下地壳和上地幔岩石学模型，结果表明，下地壳的平均化学成分比以前估计的要基本得多，第四纪火山岩的地球化学研究表明，本区火山岩具有低变质的可能性，钾质拉斑玄武岩是由含角闪石的下地壳物质部分熔融而成的。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Goyo花岗岩。Goyo花岗岩中部分无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离散的运动学事件，地震实验表明，大规模塌陷破火山口下的岩浆库以岩盖的形式存在。通过地震速度资料与地壳岩石学模型的对比，建立了与岩浆垂向系统相关的地壳结构演化新模型，并在日本本州岛东北弧进行了初步验证，目前已有多项研究成果以全文形式发表，另有一些新成果已提交多家期刊或正在筹备出版。

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.