云南富乐铅锌矿床含矿层中火山岩地球化学特征及构造意义

Fule Lead and Zinc Deposit Producing Formation Volcanic Rock Geochemical Features and Structural Significance in Yunnan

云南富乐铅锌矿区位于川滇黔多金属成矿域东南部,为了进一步了解研究区内火山岩发育特征,采用地球化学的方法分析火山岩岩石样品,结果显示此火山岩SiO_(2)含量为45.40%~50.80%,K_(2)O含量为0.82%~2.80%,Na_(2)O含量为0.01%~3.28%,为玄武岩系列,呈现出重稀土元素(HREE)相对亏损,轻稀土元素(LREE)富集,轻重稀土元素分馏特征为明显的特征,Eu变化小(δEu=0.9~1.05),绝大部分岩石中高场强元素富集,而Ba、Sr、Ti明显亏损。综合研究认为此套火山岩为大陆拉张环境下形成的板内玄武岩,并在上升过程中受到了下地壳的同化混染作用。

The Fule lead and zinc deposit in Yunnan is situated in the southeastern part of Sichuan-Yunnan-Guizhou polymetallic metallogenic zone.To further comprehend volcanic rock development features in the study area,using geochemical methods carried out volcanic rock sample analysis.The result has shown that the proportion of SiO_(2) content in volcanic rock is 45.40%~50.80%,K_(2)O content 0.82%~2.80%,Na_(2)O content 0.01%~3.28%,thus belong to basalt series.The study has exhibited HREE relatively deficient,LREE enriched,HREE and LREE fractional distillation features obvious,small variated Eu(δEu=0.9~1.05),in most rocks high field-strength elements enriched,while Ba,Sr and Ti obviously deficient.The integrated study has deemed that this set of volcanic rocks should be intraplate basalt formed under continental extension environment,during the upheaved process has come under lower crustal assimilatory hybridization.