内蒙古库伦旗卧力吐花岗岩下接触带铅锌矿床成因及其找矿意义

发布时间：2018-06-01 16:07

本文选题：铅锌矿 + 花岗岩　；参考：《南京大学》2015年硕士论文

【摘要】：内蒙古自治区库伦旗卧力吐铅锌矿床产于中亚造山带南部边缘靠近华北古陆的部位,是近年来发现和探明的大型矽卡岩型矿床。勘查结果表面在30～34线间已获得的(121b+122b+333)铅锌金属量和平均品位分别为：Pb 19.36×104t,1.27%、Zn29.11×104t,1.90%。伴生有用组分为：Ag278.05t,18.18g/t；Cu12235.52t,0.08%。矿区内与成矿有关的沉积地层主要是晚石炭统石咀组石灰岩、粉砂岩和泥岩,其总体倾向NW,倾角55。-66。；侵入岩主要是黑云母二长花岗岩。矿区的矿石类型可分为铅锌大理岩、铅锌花岗岩和铅锌矽卡岩三类。金属矿物主要为闪锌矿、方铅矿和黄铁矿,其次为磁黄铁矿、毒砂、磁铁矿和黄铜矿,并含少量白铁矿、毒砂、斑铜矿和辉银矿。脉石矿物主要为透辉石、绿帘石、绿泥石、石英、方解石、白云石和铁白云石,并有少量透闪石、阳起石和石榴石。围岩蚀变主要有透辉石化、绿帘石化、绿泥石化、硅化、碳酸盐化和黄铁矿化,局部有石榴石化、透闪石和阳起石化。矿石结构以各种不同自形程度的粒状结构为主,其次为各种交代结构结构。矿石构造均以脉状、网脉状、斑杂状、角砾状和浸染状为主。脉状矿石的脉宽多几毫米至3厘米。块状矿石仅局部出现。矿区内黑云母二长花岗岩的产出方式可以分为相互连接的两个部分：1)产状陡立的东部岩株状主侵入体；2)从岩株西侧伸出的舌状侵入体。这个岩舌从岩株西侧的深部向西伸出,往NW方向上升后侵位,其产状总体上与围岩石咀组地层一致,均向SE倾斜,表明岩舌岩浆的上升和侵位主要受该组地层的层间裂隙和破碎带控制。舌状岩体的总体积大约0.05km3。根据钻孔岩芯分析结果,整个矿区共圈出了40多个规模不等的铅锌矿体,其中资源量最大、品位最高的三个主矿体(1号、2号和3号)均产在岩舌的下接触带附近。这几个主矿体之间还普遍发育不同强度的铅锌矿化。与之成鲜明对照的是,岩舌的上接触带附近只有很小的矿体和不够工业品位的矿化。铅锌主矿体虽然紧邻岩舌之下,但其成矿流体和物质不可能是岩舌的直接产物。这是因为,迄今尚无可信的机制说明高温流体能克服浮力而从舌状岩体往下流动,然后在其下盘卸载成矿。同时,如此小的岩舌本身难以提供一个大型矿床所需要的铅锌,岩舌很快的冷却速度也使之难以在其岩浆固结之前,从与之相通的岩株获得足够的上升流体加以补充。本文认为,成矿流体和金属主要来自舌状体旁侧的岩株岩体或者更深的部位,舌状岩体下盘成矿的主要机制是对深部流体起了隔挡作用。在舌状岩体冷凝固结之后,其东侧的岩株岩浆可能正在结晶而尚未完全固结,仍有释放成矿流体的潜力。来自岩株深部岩浆体的成矿流体沿其附近的裂隙系统上升,因被已经固结的舌状岩体隔挡而聚集于其下方,并卸载而形成了工业矿体。在地壳浅部矽卡岩型矿床的形成深度内,似层状—舌状花岗岩体可能普遍存在。在这类岩体与深部上升流体共存的地段,要特别注意其下盘的找矿潜力。作者还认为,似层状—舌状岩体对深部上升流体的隔挡机制,也适用于是中温热液和浅成热液等其它一些热液矿床类型,在找矿工作中应当同样加以重视。本论文还提出了卧力吐矿区下一步找矿的有利地段。
[Abstract]:The the Inner Mongolia Autonomous Region Kulun banner lying lead-zinc deposit, located in the southern edge of the Central Asian orogenic belt, near the North China paleo land, is a large skarn type deposit discovered and explored in recent years. The results of the 30~34 lines have been obtained on the surface of the 30~34 lines: Pb 19.36 x 104t, 1.27%, Zn29.11 x 10, respectively. 4T, 1.90%. associated useful components are: Ag278.05t, 18.18g/t; Cu12235.52t, and the sedimentary strata related to mineralization in the 0.08%. mining area are mainly Late Carboniferous stone Tsui formation limestone, siltstone and mudstone, its overall tendency is NW, dip 55.-66., and intrusive rocks are mainly black mica two long granitic rocks. Ore types can be divided into lead, zinc, marble, lead and zinc ore There are three types of granite and lead-zinc skarn. Metal minerals are sphalerite, galena and pyrite, followed by pyrrhotite, arsenopyrite, magnetite and chalcopyrite, with a small amount of hematite, arsenopyrite, porphyrite and silver ore. The gangue minerals are mainly diopside, epidote, chlorite, quartz, calcite, dolomite and dolomite. The rock alteration mainly includes dioptrite, epidote, chlorinization, silicification, carbonation, and pyrite mineralization, with pomegranate fossilization, tremolite and positive petrifaction. The ore structure is mainly granular structure with various degrees of self shape, followed by various metasomatic structures. The ore structures are all with pulse and net veins. Form, variegated, breccia and disseminated mainly. The pulse width of the vein is more than 3 centimeters to 3 cm. The lump ore only occurs locally. The output mode of the biotite two granite in the mining area can be divided into two interconnected parts: 1) the steep Eastern rock type main intrusive body; 2) the tongue like intrusive body extending from the west side of the rock plant. The rock tongue protruded westward from the deep west side of the rock strain to the NW direction and emplacement, and its occurrence was in general consistent with the stone Tsui formation in the surrounding rock and inclined to the SE, indicating that the rise and emplacement of the rock tongue magma were mainly controlled by the interlayer fissure and fracture zone of the formation. The overall product of the tongue rock mass is about 0.05km3. based on the analysis of core core. A total of more than 40 lead-zinc orebodies of different sizes were found in the mining area, with the largest amount of resources, and the three main ore bodies (No. 1, No. 2 and 3) of the highest grade were all near the lower contact zone of the rock tongue. The ore body and the mineralization of insufficient industrial grade. Although the main ore body of lead and zinc is near the rock tongue, the ore-forming fluid and substance may not be the direct product of the rock tongue. This is because there is no credible mechanism to date that the high temperature fluid can overcome the buoyancy and flow down from the tongue like rock mass. The tongue itself is difficult to provide a lead and zinc needed for a large deposit. The fast cooling rate of the tongue also makes it difficult to add enough upward fluid to the rock plant that is connected to it before its magma is consolidated. This article holds that the ore-forming fluid and metal are mainly from the rock mass of the side of the tongue or the deeper part, the tongue like rock mass. The main mechanism of the footwall mineralization is to block the deep fluid. After the condensation of the tongue like rock mass, the magma on the east side of the rock may be crystallizing but not completely consolidated and still has the potential to release the ore-forming fluid. In the depth of the formation of the shallow skarn type deposits in the crust, the layered - tongue like granitoid may exist universally. In this kind of rock mass, where the deep ascending fluid coexists, we should pay special attention to the prospecting potential of its footwall. It is also suitable for some other types of hydrothermal ore deposits, such as warm and shallow hydrothermal fluids, and other types of hydrothermal ore deposits in the deep rising fluid. This paper also puts forward a favorable location for the next step of ore prospecting in the mining area of lying force spitting.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.4

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