吉林省夹皮沟花岗岩—绿岩带成因模式探讨

A PRELIMINARY STUDY ON THE GENETIC MODEL OF THE JIAPIGOU GRANITE—GREENSTONE BELT IN JILIN PROVINCE

通过对夹皮沟绿岩带层序、岩石成因以及叠加其上的变质变形作用特征的研究,认为绿岩带形成于硅铝壳的扩张环境;英云闪长岩—奥长花岗岩成分的花岗质片麻岩是在大陆或大陆边缘的挤压环境下,由变质镁铁质火山岩经部分熔融侵位的深成花岗质岩石。由此,提出夹皮沟花岗岩—绿岩带的裂谷成因模式。

Through the study on the sequence of the granite-greenstone belt, the geochemical characteristics, the granitic rocks, the metamorphism and the, deformation in the area, the following results are obtained, i.e.the greenstone belt was formed in a tectonic environment with spreading mechanism; the granite gneiss with components of tonalite-trondhjemite was chiefly composed of the ptutonic granitie rocks resulting from the emplacement of partial melting of the metamorphosed mafic volcanics under the compressive environment of continental margin or the inland. Therefore, a rift valley genetic model on the Jiapigou granite-greenstone belt is proposed.