滇东南红石岩铅锌铜多金属矿床绿帘石岩地球化学特征及构造背景  

Geochemical Characteristics and Tectonic Setting of Epidote Rocks in the Hongshiyan Pb-Zn-Cu Polymetallic Ore Deposit , Southeastern Yunnan Province

作　　者：李志强[1] 黄建国[1] 韩润生[1] 任涛[1] 王雷[1] 邱文龙[1] 

机构地区：[1]昆明理工大学国土资源工程学院,有色金属矿产地质调查中心西南地质调查所,云南昆明650093

出　　处：《地质与勘探》2013年第2期289-299,共11页Geology and Exploration

摘　　要：滇东南红石岩矿区处于NW向文山-麻栗坡和SN向马关走滑断裂的交汇处,受区域动力变质作用和深大断裂的影响,矿区内绿帘石岩较为发育。在总结矿床地质特征的基础上,笔者对矿区绿帘石岩的主量元素、微量元素和稀土元素进行了分析。结果表明:绿帘石岩具富FeO*、MnO、CaO,而Al2O3和TiO2含量较低的特征;大离子亲石元素(LILE)、Th富集,Sr、Ta、Nb、Y等元素亏损,显示火山弧玄武岩的特征,微量元素原始地幔标准化蛛网图呈"隆起"型,高场强元素(HFSE)丰度较低,低场强元素(LFSE)丰度较高,(Rb/Yb)N平均值为31.72≥1,为强不相容元素富集型,稀土元素具有ΣREE较低(平均110.05×10-6)、LREE富集(LREE/HREE平均8.34)的右倾型,轻重稀土分馏较为明显((La/Sm)N均值为4.04,∑Ce/∑Y>3)。综合主量和微量元素分析,认为研究区绿帘石岩的原岩为弧后盆地拉斑玄武岩。The Hongshiyan orefield in southeastern Yunnan Province lies in the intersection between the NW-striking Wenshan-Malipo fault and the NS-striking Maguan strike-slip fault. The regional metamorphism and major deep faults exert a critical control on the well-developed epidote rocks. This paper studies the major, trace and rare earth elements of the epidote rocks from the Hongshiyan Pb-Zn-Cu polymetallic ore deposit. The results show that： ① The average composition of the major elements is similar to the volcanic arc basalts, and the FeO^＊ , MnO, and CaO are high, Al2O3 and TiO2 are low. ② Massive meta-basah is rich in LILE （ Rb, Ba,Th）, whereas Ta, Nb,Y arc depleted, （Rb/Yb） N （31.72 on average）, similar to volcanic arc basahs ; primitive mantle-normalized diagram shows an uplift pattern. It is enriched in LFSE, relatively depleted in HFSE, similar to back-arc basin basalt. ③ REE ： EREE ratios are relatively low （ averagely 110. 05 × 10^-6 ）. It is enriched in LREE （ LREE/HREE is 8.34 on average ; （ La/Yb ） N 〉 7 ）, rare earth fractionation is relatively obvious （ （La/Sm） N is 4.04 on average ; ∑ Ce/∑ Y 〉 3 ）. ④ The discrimination diagram of environment structure suggests that the original rock of epidote rocks of the study area is back-arc basin tholeiite.

关 键 词：绿帘石岩 主量元素 微量元素 滇东南 

分 类 号：P618[天文地球—矿床学]