内蒙古东南部含锡花岗岩体成矿性研究

A Study on the Tin Mineralization of Granitic Intrusives in Southeast Inner Mongolia

内蒙古东南部花岗岩类岩体分为壳源酸性岩类和幔源中基性岩类。有已知43个花岗岩类岩体都存在一定的锡矿化。对分布于含锡花岗岩类岩体外围的28个可能含锡岩体进行科勒-拉兹图解、S iO2-A l2O3+Na2O+K2O-CaO+MgO+FeO图解、Fe-Na+K-Mg图解和K-Na-Ca图解判别后发现,壳源酸性花岗岩类完全可以用四图解进行含锡性判别,并且完全符合实际地质特征,大部分都有希望找到伴生壳源型锡矿床;而幔源中基性花岗岩类的含锡性却不适用上述四个图解进行判别。这一结论对该区壳源花岗岩体的含锡性判定具有重要意义。

Granitic intrusives in southeast Inner Mongolia are divided into two types： acid rocks of crustal origin and intermediate to basic rocks of mantle origin. Different scales of tin mineralization are found in 43 known granitic intrusives. The discriminant analyses, of 28 granitic intrusives distributed in the periphery of the stanniferous granite bodies, by using the Keluo - Lazi diagram, SiO2 - Al2O3 ＋ Na2O ＋ K2O - CaO ＋ MgO ＋ FeO diagram, Fe - Na ＋ K - Mg diagram and K - Na - Ca diagram,, indicate that the four diagrams can be applied to acid rocks of crustal origin to do the mineralization discriminant analysis, and the results are well used in field program to explore for tin deposits of crustal source. The four diagrams above - mentioned are not fit to the discriminate analysis of the mantle sourced intermediate to basic rocks.