铜陵地区高钾钙碱性侵入岩成矿分带性研究

发布时间：2018-05-05 20:16

本文选题：高钾钙碱性侵入岩 + 矿化分带　；参考：《合肥工业大学》2017年硕士论文

【摘要】：铜陵地区是长江中下游铜-铁-硫-金多金属成矿带中最重要、最典型的矿集区之一。这些铜金银铅锌多金属矿床与燕山期形成的中小型高钾钙碱性侵入岩在空间、成因上有着密切的联系,并且围绕岩体表现出规律的成矿分带。这种分带特征不仅表现在成矿温度、元素组合方面,还表现在矿床类型、成矿机制的变化上。因此,研究矿床的成矿分带性规律,可以更清楚地研究各矿床之间的共生关系、成矿系列和成矿模式,可以更清楚地解决矿床成因类型以及成因机制问题,对相似条件下的矿床的成矿预测具有相当重要的参考和借鉴意义。本文运用多种现代测试技术和手段,以铜陵地区高钾钙碱性侵入岩及其与之相关的狮子山矿田、姚家岭矿床为主要研究对象,查明了铜陵地区高钾钙碱性侵入岩的展布形态,建立并制作铜陵地区高钾钙碱性侵入岩立体模型图;查明了与高钾钙碱性侵入岩相关的矿床及蚀变带的空间分布特征、成矿元素的时空分带规律、成矿岩体的地球化学特征及其对成矿的贡献。总结出铜陵地区高钾钙碱性侵入岩成矿分带模式为:矿化类型在垂向上,从深部→浅部依次为:斑岩型矿床→矽卡岩型矿床→中低温热液型矿床;在水平方向上,由岩体至围岩依次为:斑岩型矿床→矽卡岩型矿床→中低温热液型矿床。矿石矿物在也存在明显的分带现象,自下而上:黄铜矿→磁黄铁矿→含金黄铜(铁)矿→铅锌矿;由岩体至围岩依次为:黄铜矿→磁黄铁矿→含金黄铜(铁)矿→铅锌矿。同理,矿床中的成矿元素在空间上也有明显的分带规律,自深部至浅部为:铜(金)→铜、金→金、铜→金;自岩体中心向围岩为:铜(金)→铜、金→金(铜)→银、铅、锌。结合铁、硫、铅等同位素组成的对比研究,发现该矿床的成矿元素主要是来源于岩浆或岩浆热液的。从近岩体矽卡岩→矽卡岩型矿体→近围岩岩浆热液型矿体,不同位置的Fe同位素组成随着远离岩体含矿流体向外的迁移,表现出铁同位素的时间和空间分带性,说明了成矿类型、矿石矿物、成矿元素的分带性与含矿流体演化密切相关。
[Abstract]:Tongling area is one of the most important and typical ore concentration areas in the copper-iron-sulfur-gold polymetallic metallogenic belt in the middle and lower reaches of the Yangtze River. These copper, gold, silver, lead and zinc polymetallic deposits are closely related to the small and medium high potassium calc-alkaline intrusive rocks formed during the Yanshanian period, and show a regular metallogenic zoning around the rock mass. This zonation feature is not only manifested in ore-forming temperature, element assemblage, but also in the change of ore deposit type and metallogenic mechanism. Therefore, the study of metallogenic zonation of ore deposits can more clearly study the symbiotic relationship, metallogenic series and metallogenic model among the deposits, and solve the problems of the genetic types and genetic mechanisms of the deposits more clearly. It is very important for ore-forming prediction under similar conditions. In this paper, the distribution of high-potassium calc-alkaline intrusive rocks in Tongling area and the associated Shizishan ore field and Yao Jialing deposit are studied by using a variety of modern testing techniques and means, and the distribution patterns of high-potassium calc-alkaline intrusive rocks in Tongling area are found out. A three-dimensional model map of high-potassium calc-alkaline intrusive rocks in Tongling area was established, and the spatial distribution characteristics of deposits and alteration zones related to high-potassium calc-alkaline intrusive rocks and the temporal and spatial zoning of ore-forming elements were found out. Geochemical characteristics of ore-forming rock mass and its contribution to mineralization. The ore-forming zonation model of high-potassium calc-alkaline intrusive rocks in Tongling area is summarized as follows: the mineralization type is vertical upward, and the order from deep to shallow is: porphyry type deposit, skarn type deposit, horizontal direction, The order from the rock mass to the surrounding rock is: porphyry type deposit, skarn type deposit, middle and low temperature hydrothermal deposit. Ore minerals also have obvious zonation phenomenon from bottom to top: chalcopyrite pyrrhotite bearing gold and brass (iron) ore, and chalcopyrite pyrrhotite bearing gold and brass (iron) ore from the rock mass to the surrounding rock in the order of: chalcopyrite pyrrhotite and gold-bearing copper (iron) ore. In the same way, the ore-forming elements in the deposit also have a distinct zonation law in space. From the deep to the shallow, they are: copper (gold), gold, copper and gold, and from the center of the rock mass to the surrounding rock, copper (gold), gold (copper), silver, lead, and so on, and from the center of the rock mass to the surrounding rock, the ore forming elements are: copper (gold), gold (copper) and silver, lead. Zinc. In combination with a comparative study of the isotopic compositions of iron, sulfur and lead, it is found that the ore-forming elements of the deposit are mainly derived from magma or magmatic hydrothermal solution. From the skarn type orebody near the rock mass and the magmatic hydrothermal orebody near the surrounding rock, the Fe isotopic composition in different positions moves outward from the ore-bearing fluid of the rock mass, showing the temporal and spatial zonation of iron isotopes. The ore-forming types, ore minerals and ore-forming elements are closely related to the evolution of ore-bearing fluids.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.2

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