甘肃龙首山芨岭铀矿区A型似斑状花岗岩地质特征及其地质意义
发布时间：2018-12-31 21:34
【摘要】：似斑状花岗岩是芨岭岩体重要的侵入单元,研究其特征可为钠交代型铀矿化的成因机制研究提供依据。本文通过对芨岭铀矿区外围似斑状花岗岩的岩石学、同位素年代学、地球化学研究,认为其具有低硅、富铝、贫铁和镁、低钙和较高TFe O/Mg O值的岩石化学特征,其轻稀土分馏强烈、重稀土分馏较弱,具铕中等负异常,相对富集Rb、Th、U、La、Ce、Hf、Sm、Gd,而相对亏损Ba、Nb、Ta、Sr、Ti等元素,且(Zr+Nb+Ce+Y)含量和Ga/Al值明显高于Ⅰ型和S型花岗岩均值。上述地球化学特征表明它是铝质A型花岗岩,说明早古生代(458.3±2.3Ma)祁连山-龙首山造山作用已进入晚期的后碰撞伸展环境。芨岭铝质A型似斑状花岗岩既是钠交代型铀矿的主要铀源,又为矿体定位提供充足的容矿空间。
[Abstract]:Porphyry granitoids are an important intrusive unit in the Jiling rock mass, and their characteristics can provide a basis for the study of the genetic mechanism of the Na metasomatic uranium mineralization. The petrology, isotopic chronology and geochemistry of porphyry granitoids in the periphery of the Jiling uranium deposit are studied in this paper. It is considered that they have the petrochemical characteristics of low silicon, rich aluminum, poor iron and magnesium, low calcium and high TFe O/Mg O value. The light rare earth fractionation is strong, the heavy rare earth fractionation is weak, the europium is moderately negative abnormal, and it is relatively rich in Rb,Th,U,La,Ce,Hf,Sm,Gd, and relatively depleted in Ba,Nb,Ta,Sr,Ti and other elements. (Zr Nb Ce Y) content and Ga/Al value were significantly higher than those of type 鈪，
本文编号：2397142
[Abstract]:Porphyry granitoids are an important intrusive unit in the Jiling rock mass, and their characteristics can provide a basis for the study of the genetic mechanism of the Na metasomatic uranium mineralization. The petrology, isotopic chronology and geochemistry of porphyry granitoids in the periphery of the Jiling uranium deposit are studied in this paper. It is considered that they have the petrochemical characteristics of low silicon, rich aluminum, poor iron and magnesium, low calcium and high TFe O/Mg O value. The light rare earth fractionation is strong, the heavy rare earth fractionation is weak, the europium is moderately negative abnormal, and it is relatively rich in Rb,Th,U,La,Ce,Hf,Sm,Gd, and relatively depleted in Ba,Nb,Ta,Sr,Ti and other elements. (Zr Nb Ce Y) content and Ga/Al value were significantly higher than those of type 鈪，
本文编号：2397142
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