东胜煤田侏罗系延安组煤中稀土元素地球化学特征

采用中子活化分析方法（INAA）测定了鄂尔多斯盆地东北部东胜煤田侏罗系延安组煤中稀土元素（REE）的含量,绘制了稀土元素分布类型曲线并计算了多种化学参数.在对REE的地球化学环境和地球化学特征分析的基础上,得出以下结论：①侏罗纪低灰低硫煤中REE的含量较低,且普遍低于华北盆地石炭二叠纪低灰低硫煤中的REE含量.②侏罗纪煤中的REE主要来自于物源区的陆源碎屑.东胜煤田北部靠近物源区,因此REE含量较南部高,且REE含量与灰分产率和SiO2含量有一定的相关性.③侏罗纪煤中REE的分布类型主要取决于母岩.除两个样品外,其他煤样普遍存在Eu负异常,无正Ce异常存在.④与其他岩石相比,煤中REE的分布类型极其复杂,原因在于开放盆地体系的煤中物质不断的改变和再分配.

Geochemical Characteristics of Rare Earth Elements in Yanan Formation, Jurassic System, Dongsheng Coalfield

Neutron activation analysis(NAA)was adopted to determine rare earth elements(REE)content in Jurassic Yanan Formation coals in Dongsheng coalfield,then drawing REE distribution pattern curves and calculating multiple chemical parameters. Based on REE geochemical environment and geochemical characteristic analyses,the concluding notes were made as follows:(1)REE content is low in Jurassic low ash and low sulfur coals,generally lower than in Permo-Carboniferous low ash and low sulfur coals;(2) REE in Jurassic coals is mainly come from terrigenous clastics,while the north part of the Dongsheng coal field is close by the source region,so that REE content is higher than in south part,and REE content has some correlativity with ash content and SiO2 content in coal;(3)REE distribution pattern in Jurassic coals is mainly conditional on parent rocks,except two samples,the rest are generally existed Eu negative anomaly,no Ce positive anomaly;(4)compare to in other rocks,the distribution pattern of REE in coal is very complicated,because of unceasing changing and reallocating of material in coal in an open basin system.