格尔木－额济纳旗地学断面走廊域花岗岩类的岩石化学特征与构造环境的判别

CHEMICAL CHARACTERISTICS AND TECTONIC ENVIRONMENTS OF GRANITOIDS IN THE CORRIDOR FROM GOLMUD TO EJIN QI

用花岗岩的全岩化学成分对格尔木－额济纳旗地学断面内各个地体花岗岩的岩石组合、岩石化学特征及构造类型进行了分析与对比．从北山地区到祁连地区花岗岩的酸度和铝饱和度均有增加的趋势．北山区以岛弧型＋陆弧型（ＩＡＧ＋ＣＡＧ型）、陆弧型（ＣＡＧ型）居多；祁连区以造山后型（ＰＯＧ型）为主．每个地体均出现少量非造山花岗岩，在北山区有大洋斜长花岗岩的成分，但全区未判别出典型的陆－陆碰撞型花岗岩．

In this paper the suites, chemical characteristics and tectonic environments of granitoid rocks in different terranes of the corridor have been analysed and compared with chemical compositions of total rocks. The acidity and aluminium saturation of the granitoid rocks show an increasing tendency from the Beishan area to the Qilian shan area. Most of the granitoids in the Beishan area belong to IAG+CAG and CAG types, while in the Qilian shan area the POG is dominant.In all the terraces a few anorogenic granitoids appear,but no CCG are discriminated.