秦岭群条带状混合岩矿物空间分布的研究

由于条带状混合岩具多成因,因此,研究混合岩关键的问题之一是确定其成因。矿物空间分布特征可以用来区分混合岩的成因。本文研究表明,石英正长岩质黑云杆状混合岩其脉体、基体均为聚集分布,为分异作用形成,并同变形作用有关。用Wilcoxon秩和检验对比了花岗岩和含榴矽线黑云条带混合岩的脉体,结果表明两者的矿物空间分布一致,且趋于随机分布,这些脉体为部分熔融或注入形成。区域变质岩趋向于规则分布。组成混合岩的不同部分在矿物空间分布上可有也可以没有差异,例如,含榴矽线黑云条带混合岩中古成体同脉体有明显差异,而石英正长岩质黑云杆状混合岩基体和脉体无差异。

AN INVESTIGATION ON MINERAL SPATIAL DISTRIBUTIONOF BANDED MIGMATITES IN QINGLING GROUP

Because the formation of banded migmatites is polygenetic, therefore one of the key problems in the study of migmatitesis is the determination on the genesis of migmatites. The characteristics of mineral spatial distribution may be used to distinguish the origin of migmatites. This study suggests that biotite bearing rod-like quartz-syenitic migmatite shows as aggregate distribution both in veins and substrate, such migmatite was formed under metamorphic differentiation and was related to deformation. Comparison of R- values between granitic rocks and veins of garnet-sillmanite-bearing biotite banded migmatite is performed with Wilcoxon rank-sum test, the result shows that in both of them the spatial distribution characteristics are similar and tended to be in random distribution, this kind of migmatite was formed by partial melting or injection. Regional metamorphic rocks are tended to be in regular distribution. There may or may not be any difference in mineral spatial distribution with in different parts of migmatites, eg. , the difference is obvious between paleosome and vein of garnet-sillimanite-bearing biotite banded migmatite, however, there is no difference between substrata and vein materials in biotite bearing quartz syenitic rod-like migmatite.