内蒙古中部深成侵入岩谱系单位及构造岩浆活动初探──以苏尼特左旗等8幅1：5万区域地质调查为例

ON DIVISIONS OF PLUTONIC MASSES IN THE CENTRAL INNER MONGOLIA AND ITS TECTONOMAGMATIC ACTIVITY──AN EXAMPLE FROM REGIONAL GEOLOGICAL SURVEYING IN SONID ZUOQI AREA

内蒙古苏尼特左旗地区大面积出露各地质时代的深成侵入体，它们的详细划分和归并对探讨整个内蒙古中部地区的地质发展史具有重要的意义。本文在简单描述各种侵入岩的地质特征、岩石化学特征和稀土元素地球化学特征的基础上，将它们归并为６个超单元和３个独立侵入体，并进一步探讨了它们的演化特征和形成环境。首次从岩石学的角度探讨了区域构造岩浆活动史。同时，简要报道了在该区首次发现的碱性花岗岩、Ｓ型花岗岩和堆晶角闪辉长岩。

great many plutonic intrusive masses which were formed in different geological era, are extensively distributed in Sonid Zuoqi area. Their detection, classification and characteristics are important for overall reorganization of the geological history of the whole central Inner Mongolia.Based on geological,petrochemical and REE geochemical characteristics of the plutonics,the authors divide them into 6 super-units(22 units) and 3 individual intrusive masses,and discuss their composition evolutions and genetic environments.The authors also discuss the regional tectonomagmatism activity from igneous petrologic angles.It is discovered that since Cambrian period, there were two orogenic processes:Early Paleozoic and Late Paleozoic-Late Mesozoic orogenic cycles. In addition, the authors have first discovered an A-type granitoid, two S-type granites of different tectonic phases and bojite,which has a large abundance of accumulated amphiboles.