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火山成因块状硫化物矿床越来越受到重视,喀腊达坂铅锌矿位于北东向阿尔金走滑断裂与东西向阿尔金北缘断裂夹持的喀腊大湾地区,是阿尔金北缘红柳沟—拉配泉金、铜、铁及多金属成矿带中唯一大型铅锌矿床。矿区主要出露奥陶系下统卓阿布拉克组火山沉积岩系,呈近东西走向,以向北中等角度倾斜的单斜层为特点,倾角30°~58°;矿化严格受火山沉积岩特定层位和岩性控制,即矿体均产于卓阿布拉克组第四亚组的中酸性火山岩(流纹岩、英安熔岩、英安质晶屑凝灰岩)中,矿体具有层状、似层状特点,产状稳定延伸大;最大矿体走向延伸超过2400m,倾向延深大于900m。主要有用组分Pb、Zn,伴生有用组分Cu、Au、Ag、S等。主要蚀变类型有黄铁矿化、硅化、绢云母化,地表氧化带形成黄钾铁钒化和褐铁矿化。矿石平均铅同位素组成为~(208)Pb/~(204)Pb=38.1169、~(207)Pb/~(204)Pb=15.6278、~(206)Pb/~(204)Pb=18.4684,显示矿石的铅具有上地壳铅和造山带铅的混合来源;矿石硫同位素组成平均+8.28‰,代表了海相沉积岩来源的硫与岩浆岩来源硫的混合;矿石稀土元素配分曲线与矿区及喀腊大湾地区中酸性火山岩的稀土元素配分曲线具有一致性或者相似,说明矿石与含矿中酸性火山岩具有一致的成因与来源;矿石微量元素特征显示Nb、Ta负异常与Ba的正异常,反映出存在海相沉积岩物质的混入,并具有岛弧成矿构造环境。含矿火山岩锆石SHRIMP U-Pb年龄482~485Ma,代表了矿床的形成时代为早古生代早奥陶世。综合喀腊达坂铅锌矿地质地球化学特征的研究,确认其属于火山成因块状硫化物矿床(VMS型)。所以,喀腊达坂铅锌矿成矿过程可以概括为:在早古生代奥陶纪早期北阿尔金洋发生向南的板块俯冲,板块俯冲作用导致俯冲带下盘的洋壳及其上的海相沉积物和俯冲带上盘的陆壳发生部分熔融,形成了中酸性岛弧型岩浆;在岩浆喷发的晚期,逐渐形成富含铅锌成矿物质的残余岩浆;当这些富含铅锌的残余岩浆发生喷发,最终形成了火山成因岩块状硫化物型铅锌矿床。火山岩型铅锌多金属矿床是阿尔金北缘喀腊大湾地区南带最重要勘查和预测类型,该火山岩型矿化带的西延区段是有利的找矿靶区。
The volcanogenic massive sulphide deposit has been paid more and more attention. The Kaladabange Pb-Zn deposit is located in the area of Kaladatwan that is clamped by the northeast Altyn Tagh fault and the east-west fault of the Altyn Tagh. Yuanhongliugou - La all the gold, copper, iron and polymetallic metallogenic belt in the only large-scale lead-zinc deposits. The mining area is mainly from the volcanic sedimentary rock series of the Lower Ordovician Zhu Abulak Formation and is characterized by nearly east-west inclinations and monoclinic layers inclined to the north and medium angles with an inclination of 30 ° -58 °. The mineralization is strictly controlled by volcanic sedimentary rocks Bit and lithology control, that is, the orebodies are all produced in moderately acidic volcanic rocks (rhyolite, British lava and British amphibolite) in the fourth sub-group of the Zhu Abulak Formation. The ore body has a layered, Like features, stable and extended shape; the largest ore body extends more than 2400m, the tendency to extend more than 900m. The main useful components Pb, Zn, associated useful components Cu, Au, Ag, S and so on. The main types of alteration are pyrite, silicification, sericitization, surface oxidation zone formation of jarosite vanadium and limonite mineralization. The average lead isotopic compositions of ore are 208 Pb / 204 Pb = 38.1169 207 Pb / 204 Pb = 206.6878 206 Pb / 204 Pb = 18.4684, indicating that the ore Lead has a combination source of upper crustal lead and orogenic or lead lead. The average sulfur isotopic composition of ore is + 8.28 ‰, which represents the mixing of sulfur from marine sedimentary rock and sulfur from magmatic rock. The REE distribution curves of moderate-acidic volcanic rocks in the Bay area are consistent or similar, indicating that the ore has the same origin and origin as the acidic volcanic rocks in ore-bearing. The trace elemental characteristics of ore show the negative anomalies of Nb and Ta and the positive anomalies of Ba, reflecting the existence of Marine sedimentary rock material mixed with island arc metallogenic tectonic environment. The zircon SHRIMP U-Pb ages of 482 ~ 485 Ma in ore-bearing volcanic rocks represent the Early Paleozoic Early Ordovician. Based on the study of the geological and geochemical characteristics of the Kaladadaka lead-zinc-zinc deposit, it is confirmed that it belongs to volcanic-type massive sulfide deposit (VMS type). Therefore, the ore-forming process of the Kaladadaban lead-zinc deposit can be summarized as the southward plate subduction occurred in the Early Ordovician in the early Ordovician, and the subduction of the plate resulted in the subduction of the oceanic crust and the sea surface above it The continental crust of the sediments and subduction zones are partially melted to form a medium-acidic arc-arc magma. At the late stage of magma eruption, residual magma enriched with lead-zinc ore-forming materials is formed gradually. When these lead-zinc-rich remnants Eruption occurred in the magma, eventually forming a volcanogenic rock massive sulfide lead-zinc deposits. The volcanic-type Pb-Zn polymetallic deposit is the most important type of exploration and prediction in the southern Kalladaowan area on the northern margin of the Altyn Tagh. The western extension of the volcanic-type mineralized belt is a favorable prospecting target.