铜陵狮子山铜钼金矿田控矿作用地球化学响应机制

发布时间：2018-06-03 16:27

本文选题：地球化学异常模式 + 多属性异常　；参考：《中国地质大学(北京)》2016年博士论文

【摘要】：狮子山矿田位于长江中下游铁-铜-金多金属成矿带中段的铜陵矿集区,分布有胡村南、刺山等众多铜金多金属矿床,矿床分布受断裂构造、层间滑脱构造、接触带构造控制,与燕山期中酸性侵入岩密切相关。论文在前人的工作基础上,以典型斑岩-矽卡岩型铜钼金多金属矿床为研究对象,分析了元素异常特征、硫铅同位素组成、流体包裹体特征,重点查明了矿田内地质体的元素组成及迁移规律,构建了地质-地球化学异常模式,探讨了控矿作用及其地球化学响应机制。论文取得了如下认识:1.矿田内泥盆纪-三叠纪地层、燕山期中酸性侵入岩及蚀变岩中富集成矿元素(Cu、Mo、Au)、伴生元素(Ag、As、Sb、Bi、Cd、Sb、W等)和矿化剂元素(S),亏损Ba、Sr、CaO、Na2O。矿田成矿地球化学系统中,元素带入、带出强烈,形成了大规模的正、负异常。2.矿田地表的元素异常和深部异常相吻合,Cu、Mo、Au元素正异常围绕主矿体产出,对多金属矿化具有直接的指示意义;Sr负异常紧邻矽卡岩矿体产出,是快速识别矿化体位置的有效指标。S的正异常和Ba、Na2O的负异常涵盖了整个成矿作用区域,深部依然存在,暗示可能存在隐伏多金属矿化体。3.矿田内存在由Ba、Sr、Na2O负异常体系,矿化剂元素S异常体系,S与Fe、Cu、Mo间协同平衡体系,Cu、Mo、Ag、W等成矿及其伴生元素异常体系,以及Zr、Hf元素质量守恒体系构成的多属性异常体系,其受地层、岩浆岩与叠加构造共同控制。4.狮子山矿田内Cu、Mo、Au、S等成矿物质主要来自深部岩浆及黄龙-船山组(C2+3)、栖霞组(P1q)、孤峰组(P1g)、大隆组(P2d)、龙潭组(P2l)、和龙山组(P2h)、殷坑组(T1y)等高硫地层;岩浆岩在提供成矿物质的同时,也为成矿物质活化、迁移提供了重要流体和热源。5.矿田内含矿流体在构造应力、挥发分压力、静岩压力、地温梯度差和反向构造压力的叠加作用下,经历了从高温、高盐度向中低温、中低盐度演化的连续过程,形成了多金属矿化与元素异常。6.构建了矿床、矿田尺度的地质-地球化学异常模式,这为铜陵矿集区开展地球化学勘查找矿工作和异常评价提供了依据。
[Abstract]:The Shizishan ore field is located in the Tongling ore concentration area in the middle and lower reaches of the iron-copper gold polymetallic metallogenic belt of the Yangtze River. There are many copper-gold polymetallic deposits, such as Hucuonnan and Caishan, which are controlled by fault structure, interlayer detachment structure and contact zone structure. It is closely related to acid intrusive rocks in Yanshanian period. On the basis of previous work, this paper takes the typical porphyry skarn type copper-molybdenum polymetallic deposit as the research object, and analyzes the characteristics of element anomaly, sulfur and lead isotopic composition, fluid inclusions. The elemental composition and migration law of the plastids in the interior of the ore field are found out emphatically, the geo-geochemical anomaly model is constructed, and the ore-controlling action and its geochemical response mechanism are discussed. The thesis has gained the following understanding: 1. In Devonian and Triassic strata, the ore-rich elements in the acidic intrusive rocks and altered rocks in the Yanshanian period are Cu, Mo, au, and the associated elements, the Ag-As-SbSbSbSbSbOW) and the mineralizing agent elements, Sch, and depleted Ba-Sr-CaONa _ 2O. In the ore-forming geochemical system, elements are brought in and brought out strongly, forming large-scale positive and negative anomalies. 2. The surface element anomalies and deep anomalies coincide with the positive anomalies around the main orebody, and have direct indication for polymetallic mineralization. The negative anomaly of Sr is close to the occurrence of skarn orebody. The positive anomaly of .S and the negative anomaly of Ba-Na _ 2O cover the whole metallogenic area, and still exist in the deep part, suggesting that there may be a concealed polymetallic mineralization body .3. In the ore field, there is a multi-attribute anomalous system consisting of the negative anomaly system of Ba-Sr-Na _ 2O, the system of synergetic equilibrium between the mineralizer S system and the Fe _ (Cu) Cu _ (Mo) and its associated element anomaly system, and the mass conservation system of zirconium HF elements. Magmatic rocks and superimposed structures jointly control .4. In the Shizishan Orefield, the ore-forming materials such as Cu-Mo Mo-Au-S are mainly derived from high sulfur formations such as deep magma and Huanglong-Chuanshan formation (C23), Qixia formation (P1q1), Gupeng formation (P1gng), Dalong formation (P2dN), Longtan formation (P2lhe), Longshan formation (P2h), Yinkeng formation (T1y), etc. The magmatic rocks provide the ore-forming materials at the same time. It also provides an important fluid and heat source for the activation and migration of ore-forming materials. Under the superposition of tectonic stress, volatile pressure, static rock pressure, geothermal gradient difference and reverse tectonic pressure, the ore-bearing fluid in the ore field has undergone a continuous process of evolution from high temperature, high salinity to middle low temperature and low salinity. Polymetallic mineralization and element anomaly. 6. The geological geochemical anomaly model on the scale of ore deposit and ore field is constructed, which provides a basis for geochemical prospecting and anomaly evaluation in Tongling ore concentration area.
【学位授予单位】：中国地质大学(北京)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P618.2

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