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针对塔吾尔别克金矿区赋矿火山岩展开的岩相学和主量、微量及稀土元素地球化学研究,结果显示:该区火山岩w(SiO_2)为48.93%~62.24%,w(K_2O)在1.05%~4.03%,w(TiO_2)为0.55%~0.86%,w(MgO)为2.28%~7.98%,w(Al_2O_3)介于12.04%~17.52%,w(Na_2O+K_2O)值为3.39%~5.59%,里特曼指数σ变化于1.49~2.45,显示钙碱系列火山岩;在TAS图解中该区火山岩样品分布在玄武安山岩—安山岩—英安岩区域;微量元素分析表明,岩石轻稀土相对富集、重稀土元素相对亏损的特点(LREE/HREE=4.72~6.55),且具有明显的的Eu负异常(δEu=0.35~0.67);火山岩整体富集LREE,U,Th,大离子亲石元素Rb,K;亏损高场强元素Nb,Ta,P,Ti;是岛弧岩浆作用的典型地球化学标志。在火山岩La/Yb-Sc/Ti判别图解上,表明火山岩的构造环境与大陆边缘弧密切相关。结合区域构造背景和岩石地球化学特征,推测构造背景可能为俯冲带大陆边缘弧环境。
In view of the petrology and major, minor and REE geochemistry of the volcanic rocks developed in the ore-bearing area of the Uyghur Bukuk area in the Uygur Autonomous Region, the results show that the volcanic rock w (SiO_2) is 48.93% ~ 62.24% 1.05% ~ 4.03%, w (TiO_2) was 0.55% ~ 0.86%, w (MgO) was 2.28% ~ 7.98%, w (Al_2O_3) was 12.04% ~ 17.52%, w (Na_2O + K_2O) was 3.39% ~ 5.59%, and the Rittman’s index a varied from 1.49 to 2.45, showing a series of calc-alkali volcanic rocks. In the TAS diagram, the volcanic rocks in this area were distributed in the basaltic andesite-andesite-dacite field. Trace element analysis showed that the relative light- (LREE / HREE = 4.72 ~ 6.55), and has obvious Eu anomaly (δEu = 0.35 ~ 0.67). The volcanic rocks are enriched in LREE, U, Th and large ionophilic rocks Element Rb, K; depleted high field strength elements Nb, Ta, P, Ti; is a typical geochemical marker of magmatic island magma. On the La / Yb-Sc / Ti discriminant diagram of volcanic rocks, the tectonic setting of the volcanic rocks is closely related to the continental margin arc. Combined with regional tectonic setting and lithogeochemical characteristics, it is presumed that the tectonic setting may be the continental marginal arc environment of the subduction zone.