邯邢矿区伊利石黏土岩中稀土元素地球化学特征及其地质意义

The rare earth element (REE) geochemical characteristics of illite clay rocks in Hanxing mining area and its geological significance

利用电感耦合等离子质谱法（ICP-MS）详细研究了邯邢矿区二叠系石盒子组中伊利石黏土岩的稀土元素地球化学特征.结果表明：样品稀土元素总量为22.59~570.54μg/g,平均值为163.23μg/g;w（LREE）/w（HREE）=5.41~21.82,平均值为8.87,相对富集LREE;Eu,Ce均呈负异常;δCe与δEu,（Dy/Sm）N,w（REE）三者之间的相关性表明,该区伊利石黏土岩的成岩作用对REE影响较为明显;δCe和Ceanom值的变化反映了研究区二叠系石盒子组伊利石黏土岩形成于陆相沉积环境,水介质条件为富氧环境.稀土元素分布模式、组合特征显示该区二叠系石盒子组伊利石黏土岩母岩主要为先期的沉积岩及中酸性火山岩,部分母岩为碱性玄武岩.

REE geochemical characteristics of illite clay rocks and its significance, from Shihezi Formation of Late Permian in Hanxing minning area, were studied by using ICP - MS. The results show that the REE contents range from 22.59 to 570.54 μg/g and the average content is 163.23 p,g/g. The ratios of w（ LREE）/w（HREE） range from 5.41 to 21.82, and the average value is 8.87. These characteristics show that LREE are much richer than HREE. REE distribution patterns of samples are characterized by obvious negative Ce anomaly and negative Eu anomaly. REE is obviously effected by diagenesis of the illite clay rocks according to the good relativity between 8Ce and δEu, （Dy/Sm） n, w（ REE）, respectively. According to the characteristics of δCe and Ce values, it can be concluded that the sedimentary environment of illite clay rocks from Shihezi Formation of Late Permian is mainly continental oxidized water conditions. The characteristics of REE show that the source rocks of illite clay rocks are mainly sedimentary rocks, intermediate-acidic volcanic rocks and partly alkali basahs.