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新疆东天山觉罗塔格构造带南缘寨北山铜矿区出露的下石炭统雅满苏组火山岩以中酸性火山岩为主,岩石类型包括安山玢岩和流纹岩,夹少量玄武安山岩以及同成分的火山碎屑岩。岩石主要为钙碱性系列,具富铝(Al_2O_3=12.23%~18.17%,平均15.5%)、低钛(TiO_2=0.12%~1.1%,平均0.55%)的特征;稀土元素整体上呈现轻稀土相对富集、重稀土相对亏损的右倾型稀土配分模式,富集K、Rb、Pb、Th等大离子亲石元素(LILE)、亏损Nb、Ta、Ti等高场强元素(HFSE);Ta/Yb值、Zr/Nb值、Zr/Y值分别为0.10~0.27、15.97~38.34和4.11~12.55。其可能形成于早石炭世古康古尔洋向南俯冲作用的岛弧环境,为俯冲洋壳与地幔楔岩石交代反应的产物。铜矿体赋存于雅满苏组火山岩中,虽与铁矿的赋矿地层雅满苏组时代相同,但赋矿火山岩岩石类型和地球化学特征不同,铜矿床含矿岩体可能是板片俯冲下大洋板片熔融,在岩浆熔融上升过程中同时析出金属,与地幔楔发生交代作用,在合适位置富集成矿。
The Lower Carboniferous Yamanasu volcanic rocks exposed in the Qinshan Beishan copper deposit in the southern margin of the Qionglatahg tectonic belt of East Tianshan, Xinjiang, are mainly medium-acidic volcanic rocks. The rock types include andesite and rhyolite, with a small amount of basaltic andesite As well as pyroclastic rocks of the same composition. The rocks are mainly calc-alkaline series with the features of rich aluminum (Al 2 O 3 = 12.23% ~ 18.17%, average 15.5%) and low titanium (TiO 2 = 0.12% -1.1%, average 0.55% Rb, Pb, Th and other large LILEs, depleting high field strength elements (HFSE) such as Nb, Ta and Ti; and Ta / Yb value, Zr / Nb value and Zr / Y value are respectively 0.10-0.27, 15.97-38.34 and 4.11-12.55. It may be formed in the island arc environment of the Early Carboniferous Gujunkou ocean subducting southward, which is the product of the reaction of subducting oceanic crust and mantle wedge rock. The copper ore bodies occur in the volcanic rocks of the Yaman Ssu Formation. Although the same type of strata as the Yanmusu Formation in the iron ore deposits, the rock types and geochemical characteristics of the volcanic rocks of the ore-dressing are different, and the ore-bearing rock mass of the copper ore deposits may be the plate The subduction of the oceanic plate under the subduction melts, simultaneously precipitates the metal during the melting and rising of the magma, and interacts with the mantle wedge to enrich the mineralization in a suitable place.