摘要
蒙古固阳地区分布着广泛的新太古代变质侵入岩,总体呈东西向带状,展布方向与区域构造线方向一致。岩石类型为变质石英闪长岩、斜长花岗岩。变质石英闪长岩类中,SiO2含量为50.88%～59.60%,Al2O3为15.35%～18.03%,Na2O>K2O;变质斜长花岗岩类中,SiO2含量为63.54%～69.70%,Al2O3为15.66%～19.32%,与BarKer和McGregor所定义的典型奥长花岗岩相似。稀土配分型式与高铝型TTG岩石的演化趋势相一致,87Sr/86Sr=0.702448±0.000003,Ii值为0.7013。石英闪长岩中获得一组单颗粒锆石U-Pb同位素年龄在2575～2676Ma之间。新太古代变质侵入岩中分布着小型金矿或金矿点10余处,金矿床的分布与这类侵入岩具有空间和时间上的密切联系。该类侵入岩于特殊构造背景下形成,是古老地块裂解、焊接活动的产物。
In Guyang region of Inner Mongolia widely distribute a lot of Neoarchean intrusives in the same direction with the reginal structure EN line.The main rocks are metamorphic quartz diorite and plagiogranite .The SiO2 content in the quartz diorite is 50.88%～59.60%, and Al2O3 is 15.35%～18.03%,Na2O>K2O. The SiO2 content in the metamorphic plagiogranite is 63.54%～69.70%,and Al2O3 is 66%～19.32%,resemble to the typical trondhjemite by BarKer and McGregor's definition.The REE patterns are the same with the high-Al-type TTG.87Sr/86Sr =0.702 448±0.000 003,Ii is 0.7013.The Single Zircon U-Pb Ages from the quartz diorite are between 2 575～2 676 Ma. More than 10 gold ores /spots distribute in the intrusives, and they have the closely space-time relationship with the intrusives. The intrusives are formed in the background of the activity of old-land block breaking and connecting.
出处
《地质调查与研究》
2003年第1期21-26,共6页
Geological Survey and Research
基金
国家地质大调查项目(10101115015)
