【作者】 车勤建；

【导师】 杜杨松；

【作者基本信息】 中国地质大学（北京） ， 矿物学岩石学矿床学， 2005， 博士

【摘要】 本论文在收集和整理大量有关湘南锡多金属矿集区成矿地质背景和成矿地质特征以及岩浆作用和多金属成矿资料的基础上,通过典型矿床和岩浆岩岩体的解剖以及成矿流体及其成矿作用(包括成矿流体的主要成分、性质和成矿流体大规模运移的机理,特别是成矿流体和成矿作用的相互关系等)的研究,探讨了湘南锡多金属矿集区燕山期花岗质岩浆活动、流体作用与成矿过程,取得了以下主要成果。1、归纳了湘南地区的区域构造演化历史以及构造格局特征,分析了区域成岩与成矿的地球化学背景,认为湘南地区呈NE 与NW 向的各级断裂构造的发展对区内燕山期的大规模成矿起到了重要的制约作用。围岩以及特征的岩性组合与成矿存在着密切的联系。2、总结了区内多个典型中酸性岩体的特征,认为燕山期形成的中酸性岩体为本区的成矿提供了重要的物质来源。以骑田岭岩体和千里山岩体为例,对岩体的地球化学特征进行了分析对比,探讨了区内岩浆活动与成矿作用时空演化的规律性。3、对以锡、钨、铅锌为主的多金属矿床进行了类型划分,将矿集区内的多金属矿床分为热液型矿床、矽卡岩型矿床、似层控热液型矿床等,并以芙蓉矿田内的白腊水锡矿床为解剖重点,辅以对其他类型矿床的分析,探讨了区内成矿作用与燕山期岩浆活动的成因联系。4、通过典型矿床的流体包裹体测定和硫、铅、氢、氧等同位素分析,初步查明了燕山期成矿流体的特征和成矿物质来源。成矿流体大体属NaCl～KCl～CaSO4～H2O 体系,富碱和挥发分。利用流体包裹体Rb-Sr 定年方法获得的成矿年龄为177±3Ma。硫同位素分析结果表明硫来自地壳深部混合硫源,而铅同位素分析结果反映其来源存在多源性。5、通过对构造环境、矿化蚀变、矿石特征以及物化条件对成矿的影响等几个方面的研究,结合成矿流体的循环、流体中的矿质富集以及矿质的结晶沉淀的分析,初步建立了区域花岗质岩浆活动—流体作用—成矿过程模型。更多还原

【Abstract】 A great number of data have been collected and sorted out on the metallogenic geological settings and characteristics as well as magmatism and polymetallic metallogeny of major tin-polymetallic deposit-concentrated areas in South Hunan. Meanwhile, a detailed study has been conducted on the typical deposits and magmatic plutons, especially ore-forming fluids with their activities, including composition and character of ore-forming fluids and their large scale migration mechanism, as well as relationship between ore-forming fluid action and metallogeny. Based on the data and study, a discussion has been made on the Yanshanian granitic magmatic to hydrothermal mineralization processes. The following are the achievements that have been acquired in this study. 1. A summarization on the regional tectonic evolution history and tectonic pattern in South Hunan combined with an analysis on the geochemical background of regional magmatism and metallogeny has been made, leading to inference that the development of different grade faults in NE and NW directions could play an important role in the Yanshanian large scale mineralization. It is suggested that surrounding rocks with assemblages of special lithologies are closely related to regional metallogeny. 2. It is proposed based on the summarization of characteristics of several typical felsic plutons and features of magmatic activities that a large part of materials for mineralization in the area might be derived from the Yanshanian felsic plutons. Analyzing with comparison on geochemical characteristics of the felsic plutons exampled by the Qitianling and Qianlishan plutons gives a clue to better understanding regularities of temporal and spatial evolution of the magmatic activities associated with metallogeny in South Hunan. 3. The polymetallic deposits dominated by tin, tungsten, lead and zinc deposits in the deposit-concentrated areas are classified into hydrothermal, skarn and stratabound-like hydrothermal types of deposits. Investigation on major types of ore deposits, especially the Bailashui tin deposit within the Furong ore field provides new insight into understanding the relationship between regional mineralization and Yanshanian magmatic activities. 4. Fluid inclusion measurement combined with sulfur, lead, hydrogen and oxygen isotopic analysis on ores from the typical deposits leads to preliminary ascertaining characteristics of the Yanshanian ore-forming fluids and derivations of ore-forming materials. The ore-forming fluids are rich in alkalis and volatiles, and totally belong to a NaCl～KCl～CaSO4～H2O type. The mineralization age is measured by using Rb-Sr dating of fluid inclusions to be 177±3 Ma. Sulfur isotopic analyses are consistent with derivation of sulfur from a mixed source in deep crust, and lead isotopic analyses support derivation of lead from multiple sources. 5. A preliminary model for the regional granitic magmatic to hydrothermal mineralization processes is set up on the basis of the researches on tectonic setting, mineralization and alteration, ore characteristics, and influence of physicochemical condition variation on metallogeny combined with the analyses on circulation of ore-forming fluids, enrichment of ore-forming materials in the fluids, and precipitation of metals from the fluids.更多还原