论文部分内容阅读
侵位于义敦岛弧带中北段的措交玛花岗岩体形成时代为印支期至燕山早期,岩石类型为二长花岗岩、花岗闪长岩。铀矿化主要赋存于北西—南东向达郎松沟断裂(F_(30))之次级构造裂隙带细粒黑云母花岗岩中,矿化围岩为上三叠统曲嘎寺组(T_3q)英安质流纹岩。正常段与矿化岩石地球化学特征表明:矿化岩体富硅w(SiO_2)平均=74.60%、富碱w(Na_2O+K_2O)平均=7.94%、铝过饱和w(Al_2O_3)平均=12.20%、结晶分异作用强烈(DI)平均=86.49,属高钾钙碱性系列,成因类型为后造山A型花岗岩;微量、稀土元素地球化学特征表明,正常段与矿化具有相同的富集和亏损规律,显示措交玛花岗岩体为铀成矿的形成提供了铀源。
During the Indosinian to early Yanshanian period, the Qogacama granite intrusive in the central-northern part of the Yidun Island arc belt was formed with monzogranite and granodiorite. The uranium mineralization mainly occurs in the fine-grained biotite granites in the secondary structure of the Talangonggou fault belt (NW-SE) and the mineralized wall rocks are the Quaternary Quaternary T_3q) British amphibolite. The geochemical characteristics of normal and mineralized rocks show that the mineralized rock mass is rich in silicon (SiO 2) = 74.60%, the average Na + / K 2 O is 7.94% and the average value of Al 2 O 3 is 12.20% (DI) = 86.49. It belongs to the high-K calc-alkaline series and the genetic type is post-orogenic A-type granite. The trace elements and REE geochemical characteristics show that the normal and mineralization have the same enrichment and The depletion pattern shows that the Cuocamama granite body provides a uranium source for the formation of uranium mineralization.