大水金矿区碳酸盐岩稀土元素地球化学特征及其成因初探  

REE GEOCHEMISTRY AND ORIGIN OF CARBONATITE IN DASHUI GOLD MINE

作　　者：代文军 史文全 彭秀红[2] 闫海卿[3] 

机构地区：[1]甘肃省地矿局第三地勘院,甘肃兰州730050 [2]成都理工大学,四川成都610059 [3]长安大学,陕西西安710064

出　　处：《甘肃地质》2015年第4期16-21,27,共7页Gansu Geology

摘　　要：大水金矿区广泛发育碳酸盐岩,大量的稀土元素分析发现区内不同类型碳酸盐岩（未矿化和矿化）显示出不同的稀土元素地球化学特征。研究表明,未矿化碳酸盐岩样品稀土元素配分模式为较一致略向左倾斜,重稀土谱线呈锯齿状,具强烈的Eu正异常（δEu=11.32~13.13）和中等Ce正异常（δCe=1.24~1.61）;矿化碳酸盐岩样品稀土元素配分模式为较一致略向右倾斜的曲线,具弱Eu负异常→无Eu异常→弱Eu正异常（δEu=0.60~1.19）和Ce负异常明显—不明显（δCe=0.55~0.88）。未矿化碳酸盐岩在成岩过程中有热水作用的参与,是热水与海水相互作用的产物;矿化碳酸盐岩是热水、大气降水及深源流体与海相碳酸盐反应的产物。A large number of carbonatite exist in Dashui gold mine district. REE geochemistry of these carbonatite show that REE partition of unmineralized carbonatite is inclined to left, spectrum of heavy REE is indentation, Eu act as a strong positive anomaly（δEu=11.32~13.13）, and Ce as intermediate positive anomaly; but REE partition of mineralize carbonatite is inclined to right slightly, Eu act as a slightly negative anomaly--non anomaly-slightly positive anomaly（δEu =0.60 ~1.19）, and Ce as intermediate obviously negative anomaly-unobvious anomaly. These may be illustrated that the unmineralized carbonatite was the product of hot water and seawater in the process of rock formation, but the mineralized carbonatite was the product from the reaction of marine carbonate with hot water, meteoric water and deep source fluid.

关 键 词：稀土元素地球化学 岩石成因 碳酸盐岩 金矿床 甘肃大水 

分 类 号：P618.51[天文地球—矿床学] P595[天文地球—地质学]