CHANGE OF ARC-MAGMATISM FROM THE PALEOZOIC IN NORTHEAST JAPAN

本项目的目的之一是弄清北上山脉在冈瓦纳大陆中的位置和性质。（1）提出了北上山脉中晚古生代岩浆活动与冈瓦纳大陆形成、发展和扩散的关系。(2)从早白垩世花岗岩活动看北上山脉与北海道西南部的构造关系。(3)本文从阐明蒙古-鄂霍次克褶皱带与日本东北部岩浆活动关系的角度，研究了蒙古早中生代至晚古生代锂氟花岗岩的特征。(4)利用数字高程模型研究了晚中生代至现代岩浆活动和构造运动的分布和结构。结果表明，在北上山脉中发现了新的线性构造和曲线构造，并在山脉中发现了花岗岩体。

The one of the purposes of this project is to clarify the position and characters of the Kitakami Mountains in the Gondwanaland. Our results of the project are as follows : (1) We proposed the relation between the Middle to Late Paleozoic igneous activity in the Kitakami Mountains and the formation, development and dispersion of the Gondwanaland. (2) The tectonic relation between the Kitakami Mountains and Southwestern part of Hokkaido from the point of view on the Early Cretaceous granitic activity. (3) Characteristics of the Early Mesozoic to Late Paleozoic lithium - fluorine granites in Mongolia have been investigated from the point of view to clarify the relation of the igneous activity of the Mongolia - Okhotsk Fold belt and Northeast Japan. (4) The distribution and structure of the Late Mesozoic to Recent magmatism and tectonic movements have been investigated by using the Digital Elevation Model. From the results, new lineaments and curvilinear structures are observed in the Kitakami Mountains and granitic plutons in the Mountains.