准格尔煤田高铝煤层夹矸中稀土元素地球化学特征及意义

利用电感耦合等离子质谱法(IPC-MS)详细研究了准格尔煤田石炭系太原组中高铝煤层夹矸的稀土元素地球化学特征。研究表明:样品稀土元素总量(ΣREE)为3.63~345.56μg/g,平均值为61.83μg/g,轻、重稀土元素的含量比值(LREE/HREE)为0.56~25.64,平均值为5.56,相对富集LREE;Eu负异常显著;δCe与δEu、(Dy/Sm)N、ΣREE三者之间相关性表明:该区高铝煤层夹矸的成岩作用对REE影响不明显;δCe和Ceanom值的变化反映了研究区高铝煤层夹矸形成于陆相环境,高铝矿物形成于氧化环境;稀土元素分配模式显示高铝煤层夹矸物源主要为盆地北缘阴山古陆的加里东海西期的花岗岩(斜长花岗岩、二长花岗岩、钾长花岗岩和细晶花岗岩),以及早期沉积的本溪组铝土矿。

Geochemical characteristics of rare earth element in high-alumina partings in Jungar Coalfield

REE geochemical characteristics of high-alumina partings,from Taiyuan Formation of Carboniferous in Jungar Coalfield,were studied by using ICP-MS.The results show that the REE contents range from 2.63 to 345.56μg/g,and the average 61.83μg/g.The ratios of LREE/HREE range from 0.56 to 25.64,and the average 5.56.These characteristics show that LREE are much richer than HREE.REE distribution patterns of samples are characterized by obvious negative Eu anomaly.REE is not obviously effected by diagenesis of the high-alumina partings according to the bad relativity between δCe and δEu,（Dy/Sm）N,ΣREE,respectively.According to the characteristics of δCe and Ceanom values,it can be concluded that the sedimentary environment of high-alumina partings is mainly continental oxidized water conditions.The characteristics of REE show that the material source of high-alumina partings are from Yinshan ancient continent,and its provenance are mainly Caledonian-Hercynian granites,such as plagioclase granites,adamellites,moyites and aplitic granites,and bauxite deposits from Benxi Formation.