河南省栾川—嵩县地区萤石矿床稀土元素地球化学特征及成因

本文总结了河南省栾川—嵩县地区萤石矿床的地质特征,并研究矿床的萤石稀土元素特征,以探讨矿床的成矿物质来源、成矿流体演化以及矿床成因。结果显示,栾川—嵩县地区萤石矿床的萤石样品ΣREE含量范围7.17×10^–6～178.02×10^–6,平均值67.85×10^–6,LREE/HREE值范围0.30～4.31,平均值1.80,δEu范围0.21～1.04,平均值0.64, δCe范围0.11～0.93,平均值0.76。萤石矿床的萤石稀土元素配分曲线形态整体上具有平坦型特点,萤石呈中等Eu和Ce负异常。通过对比萤石矿床的萤石、地层岩石和中生代花岗岩的稀土元素特征及分析各地质体主要成矿元素Ca和F的丰度,认为研究区大规模萤石成矿的物质主要来源于太华群、熊耳群地层,其次是中生代花岗岩体或岩浆期后热液;大气降水的参与以及成矿流体的运移是成矿流体由还原环境向氧化环境逐渐过渡的主要因素。萤石稀土元素La/Ho-Y/Ho关系图表明,萤石成矿在大尺度时间范围内具有同源性、小尺度时间范围内具有同源不同期性的特点。栾川—嵩县地区萤石矿床是由地层岩...

The Geochemical Characteristics of Rare Earth Elements and Genesis of the Fluorite Deposits in Luanchuan–Songxian Area,Southwest Henan Province

The geological characteristics and rare earth elements of fluorite deposits in Luanchuan–Songxian area, Henan Province were studied in order to discuss the metallogenic materials, evolution of ore-forming fluids, and the genesis of the deposits. The results show that the ΣREE content, LREE/HREE value, δEu and δCe of fluorite samples are 7.17×10–6~178.02×10–6, 0.30~4.31, 0.21~1.04 and 0.11~0.93, and their average value are 67.85×10–6, 1.80, 0.64 and 0.76 respectively, and that chondrite-normalized REE patterns of fluorite is flat on the whole, and the fluorite has medium Eu and Ce negative anomaly. By comparing the rare earth element characteristic values of fluorite, stratigraphic rocks and Mesozoic granite and analyzing the abundance of Ca and F of geological body, it is considered that the metallogenic materials of deposits which were generated in large-scale fluorite mineralization were mainly derived from Taihua group and Xionger group strata and secondly from Mesozoic granite or post-magmatic hydrothermal fluids, and the participation of meteoric water and the migration of ore-forming fluids were the main factors for the gradual transiton of ore-forming fluids from reducing to oxidizing environment. The La/Ho-Y/Ho relationship diagram shows that the fluorite mineralization has the characteristics of homology in the large-scale time range and has different periods in small-scale time range. The fluorite deposits in Luanchuan–Songxian area are fault-controlled hydrothermal deposits whose metallogenic materials were derived from strata, magmatic rocks and post-magmatic fluids which provided driving heat for mineralization, and whose main ore-forming water were meteoric water.