【摘要】：似斑狀花崗巖是芨嶺巖體重要的侵入單元,研究其特征可為鈉交代型鈾礦化的成因機制研究提供依據(jù)。本文通過對芨嶺鈾礦區(qū)外圍似斑狀花崗巖的巖石學、同位素年代學、地球化學研究,認為其具有低硅、富鋁、貧鐵和鎂、低鈣和較高TFe O/Mg O值的巖石化學特征,其輕稀土分餾強烈、重稀土分餾較弱,具銪中等負異常,相對富集Rb、Th、U、La、Ce、Hf、Sm、Gd,而相對虧損Ba、Nb、Ta、Sr、Ti等元素,且(Zr+Nb+Ce+Y)含量和Ga/Al值明顯高于Ⅰ型和S型花崗巖均值。上述地球化學特征表明它是鋁質(zhì)A型花崗巖,說明早古生代(458.3±2.3Ma)祁連山-龍首山造山作用已進入晚期的后碰撞伸展環(huán)境。芨嶺鋁質(zhì)A型似斑狀花崗巖既是鈉交代型鈾礦的主要鈾源,又為礦體定位提供充足的容礦空間。
[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，

本文編號：2397142