内蒙古上库力地区萤石矿稀土元素地球化学特征及成因探讨

Geochemical characteristics and genesis of rare earth elements in fluorite deposits in the Shangkuli area,Inner Mongolia

通过对上库力地区萤石矿石微量元素、稀土元素地球化学特征研究,表明该地区萤石矿的微量元素表现为亏损Ti、Zr、Nb、Th,富集U、Sr、Sm,一定程度上反应了萤石矿床形成过程中源区的相似性。萤石矿的稀土元素地球化学配分模式分为轻稀土富集型及轻稀土亏损型,二者含量萤石的稀土元素总量差别较为明显,且与围岩分配模式大体一致。Eu既有正异常也有负异常,反映成矿流体既有氧化环境又有还原环境;Ce表现为弱的负异常,一定程度上反应该地区萤石成矿流体演化的一致性。综合分析研究表明,上库力地区萤石矿成因类型为为中低温热液充填型矿床,成矿物质来源为同源。

By studying the geochemical characteristics of the trace elements and rare earth elements of the fluorite ore in the Shangkuli area, the trace elements of the fluorite deposits in this area show a loss of Ti, Zr, Nb and Th, and the enrichment of U, Sr and Sm,to a certain extent, the similarity of the source region during the formation of the fluorite deposit. The geochemical distribution pattern of the rare earth elements in the fluorite deposit is divided into light rare earth enrichment and light rare-earth loss type. The total amount of rare earth elements in the two fluorite is quite distinct, and is in accordance with the distribution pattern of the surrounding rock. Eu has both positive and negative anomalies, reflecting the oxidation and reduction environment of the ore-forming fluid,and the Ce expression is weak negative anomaly,to a certain extent,the evolution of the fluorite ore-forming fluid in the region should be in a certain degree. Comprehensive analysis shows that the genesis of fluorite deposits in the Shangkuli area is a medium low temperature hydrothermal filling type, and the source of the ore-forming material is homologous.