论文部分内容阅读
石炭系企鹅山群第二组火山-沉积岩是土屋铜矿的围岩,岩性以玄武岩为主。玄武岩为钠质亚碱性玄武岩;w(SiO2)为50.65%~54.13%;w(Al2O3)为16.48%~18.89%;w(Na2O)为2.02%~3.9%;w(K2O)为0.098%~1.76%;全碱w(Na2O+K2O)为2.118%~5.21%。微量元素蛛网图右倾,大离子亲石元素富集,高场强元素相对亏损,Nb-Ta负异常明显。稀土总量较低,ΣREE 50.64×10-6~117.73×10-6,轻稀土富集,轻重稀土分馏不明显,LREE/HREE为3.40~7.15,Eu为0.98~1.14,没有发生明显的斜长石结晶分异作用,δCe为0.94~0.99,氧化条件弱。玄武岩主量元素、微量元素、稀土元素结合构造环境图解分析显示企鹅山群第二组火山-沉积岩形成于岛弧环境。
The second group of Volcano-Sedimentary rocks in Penguin Group of Carboniferous is the surrounding rock of Tuwu Copper Mine, with the basalt as the main lithology. Basalts are sodium subbasin basalts; w (SiO2) is 50.65% -54.13%; w (Al2O3) is 16.48% -18.89%; w (Na2O) is 2.02% -3.9%; w (K2O) is 0.098% 1.76%; all the base w (Na2O + K2O) was 2.118% ~ 5.21%. The microelement cobweb diagram is tilted to the right, the enrichment of large ion lithophile elements, the relative loss of high field strength elements, and the negative Nb-Ta anomaly. The total REE content is low, ΣREE 50.64 × 10-6 ~ 117.73 × 10-6, light rare earth enrichment, light and heavy rare earth fractional distillation is not obvious, LREE / HREE 3.40 ~ 7.15, Eu 0.98 ~ 1.14, no obvious ramp Stone crystallization differentiation, δCe 0.94 ~ 0.99, the oxidation conditions are weak. The basaltic elements, trace elements and rare earth elements in the basalt show that the volcanic-sedimentary rocks of the second group formed in the island arc environment.