个旧锡铜多金属矿区成矿多样性及定量评价

发布时间：2018-08-16 13:35

【摘要】：个旧锡铜多金属矿区有着上百年研究的历史,国内外诸多专家和学者们对个旧从各个方面都进行过详尽的研究,相关的研究成果也非常丰硕。但受前人找矿指导思想的影响,长期以来个旧锡铜多金属矿区的找矿和开采重点是地表砂矿、矽卡岩型硫化物矿床以及层间氧化物矿等几种类型的矿床,而对于蚀变花岗岩型矿床、与煌斑岩有关的矿床以及与喷流沉积有关的矿床等类型没有给予足够的重视。这些不同类型的矿床体现了个旧地区成矿的多样性,而成矿多样性特征在云南个旧锡铜多金属矿区的表现非常明显。在空间上的表现为矿床的空间分布从上至下大致有地表砂矿、层间氧化矿床、接触带矽卡岩型硫化物矿床,以及近些年在老厂东发现的岩体内部与蚀变花岗岩有关的铜多金属矿床。在成因方面从最开始一致认为的岩浆热液成因论到海底热液喷流成因的提出,再到多期、多源和多因复成矿床观点日趋得到认可,随着认识的加深以及新的矿床类型不断发现,个旧地区矿床成因多样性不断地在丰富。成矿多样性和矿床谱系的问题自从提出以来,前人对云南个旧锡铜多金属矿区的成矿多样性方面有一定的研究,但随着近几年来有新的矿床揭露和进一步的研究程度的提高,个旧地区的成矿多样性和矿床谱系有待进一步地补充完善。本文主要指导思想为赵鹏大等人提出的“三联式”定量成矿预测理论。“三联式”定量成矿预测理论是以地质异常、成矿多样性以及矿床谱系为主要研究对象,分析地质异常是基础,研究成矿多样性以及矿床谱系的特征做为指导,并且对各种矿化信息和特征以及成矿规律定量化的研究。加强这三者研究之间的相关性,可以清楚地认识到因果关系,地质异常(原因)-成矿多样性(表现形式)-矿床谱系(表现规律)。它最终是要分析研究某地成矿多样性的特征,并在此基础上建立矿床谱系,将预测的对象放在该地整个成矿时间谱系、空间谱系以及成因谱系中研究,以此来进行矿床预测。本文对云南个旧锡铜多金属矿区内主要成矿类型在成矿时代、矿床分布空间、成矿物质来源以及矿床成因类型等方面的成矿多样性特征进行分析,在分析成矿多样性特征的基础上分别建立了个旧锡铜多金属矿区的矿床时间谱系、矿床空间谱系以及与前两者相关的“时-空-因”综合谱系。并在此基础上,对成矿多样性矿床地球化学特征以及成矿多样性空间特征按不同矿床类型分别进行对比分析,探求这些矿床类型多样性特征的异同点。最后利用“5P”定量成矿预测方法后两步首先对个旧地区东矿区主要金属矿产资源潜力进行定量预测与评价,其次对个旧老卡岩体地段深部类似于西凹铜多金属矿床的找矿前景进行评价。本文所取得的主要认识有：1、云南个旧地区岩浆活动以及构造运动频繁,使得成矿地质条件复杂,形成了个旧矿区内种类繁多的锡铜多金属矿产资源,为成矿多样性的研究提供了基础。本文分别从成矿时代、矿床分布空间、成矿物质来源和矿床成因类型等方面分析了成矿多样性在云南个旧地区的表现特征。2、在成矿多样性分析基础上,结合前人研究成果,按成矿时代和含矿建造划分了四个成矿系列,与燕山期碱性岩有关的稀有、放射性及有色金属-非金属矿床成矿系列(Ⅰ)与燕山期花岗岩有关的稀有、有色及贵金属矿床成矿系列(Ⅱ),与燕山期斑岩脉有关的有色及贵金属矿床成矿系列(Ⅲ),以及与喜马拉雅期陆相沉积及表生改造有关的稀有、有色及贵金属矿床成矿系列(Ⅳ)。其中系列Ⅰ-Ⅲ为燕山晚期岩浆-热液内生成矿作用的产物,系列Ⅳ为前三个系列经后期表生改造的产物。将蚀变花岗岩型铜多金属矿床划分到系列Ⅱ中与花岗岩浆期后气化高温热液有关的稀有、有色及贵金属矿床成矿亚系列(Ⅱ-1)3、在分析个旧锡铜多金属矿区成矿多样性的表现特征基础上,总结建立了矿床时间谱系和矿床空间谱系以及矿床“时-空-因”综合谱系。个旧锡铜多金属矿区主要成矿时代为燕山晚期,伴随区域岩浆活动和构造运动开始大规模的成矿作用,形成岩浆期后热液矿床及其他相关的成矿类型。喜马拉雅期存在一定规模的风化-沉积成矿作用,以层间氧化矿床以及各种砂锡矿床为代表。矿体空间分布的总体是围绕个旧杂岩体呈不对称的环状、带状展布,以花岗岩体为中心由内向外分为岩体内接触带、正接触带、岩体外接触带和地表的矿体空间分布特征,并大致表现为Be-W、Sn (Cu、Mo、Bi、Be)-Sn、Pb、Ag-Pb、Zn的元素分带特征。以成矿时代、成因类型为纵坐标,以成矿密集区内矿床空间分布为横坐标,建立了个旧锡铜多金属矿区矿床“时-空-因”综合谱系图。最后对比滇东南地区钨锡多金属矿床“时-空-因”综合谱系图,在不同尺度内对矿床谱系进行了比较。4、西凹铜多金属矿体赋存于岩体内部花岗岩边缘相的蚀变岩带中,处于岩体形态由陡变缓的特殊部位,属于中小型矿床,其成矿元素的品位较高,矿体中Cu的平均含量大致为1.79%,Sn的平均含量约为0.51%。成矿作用与蚀变作用关系密切,矿床的围岩蚀变类型众多,其中与成矿作用关系密切的蚀变类型有钾长石化、萤石化和电气石化。蚀变分带不具明显对称性,按主要蚀变类型分为钾长石化带和绿帘石化带两个大的蚀变带,其中钾长石化带可见明显矿化。成矿物质来源极有可能是侵入的黑云母花岗岩,矿体赋存空间位置也暗示成矿物质与黑云母花岗岩的关系密切,侧面反映成矿物质的来源。结合矿体形态、蚀变带的空间位置分布和蚀变带接触的突变性,推测矿体赋存的空间极有可能为含矿热液运移的通道,在充填交代作用下成矿。含矿热液中金属元素的迁移形式应以氟化物、氯化物的络合物为主。5、选取个旧锡铜多金属矿区各大矿田内矿床的典型成矿类型,主要包括层间氧化矿床、接触带矽卡岩型硫化物矿床、变玄武岩型硫化物矿床以及蚀变花岗岩型铜多金属矿床,将每种矿床类型分布在不同矿田内的地球化学特征进行分析对比。将这些不同成矿类型矿床的矿石微量元素和稀土元素作为研究对象,主要分析对比了成矿元素及其伴生元素含量、微量元素相关性、稀土元素特征和元素特征值等地球化学特征。6、同样选取如前所述的四种成矿类型,以矿床中成矿元素的含量为主要研究对象,分析对比了相同成矿类型的矿床在不同矿田的矿段内的空间分布情况,以及主要成矿元素铜和锡元素含量的标高分布情况,含量值的大小,高值区间的分布等,以及成矿元素含量在垂向上的变化情况等。7、在成矿多样性分析及成矿谱系建立的基础上,结合云南个旧地区研究程度和所收集的相关资料,利用“5P”定量成矿预测方法后两步对个旧东区进行定量评价。对个旧地区东矿区主要金属矿产资源潜力进行定量预测与评价,圈定出五个矿产资源体的潜在地段并进行评价,其中成矿潜力较大的为松矿西靶区(Ⅱ)、竹叶山靶区(Ⅳ)和大白岩南靶区(V)。其次对个旧老卡岩体地段深部类似于西凹铜多金属矿床的找矿前景进行评价,探寻此类矿床时,需要查明蚀变特征,尤其是钾长石化这种蚀变。可以利用不同中段的坑道中多种微量元素的原生晕异常特征来进行辅助判断,如Cu、Sb、Bi、Pb、Sn、Cd和Be这些元素,在深处矿体顶部相应位置均有不同的异常特征。而像前缘晕较发育的元素,如As、Ag、Pb和Zn这些元素,在岩体浅部这些元素开始富集的地区,可以作为深部存在矿体的依据之一。还有一些元素,如Sr和Ba元素,其原生晕的分布非常有特征,针对岩体界面无法利用常规方法获得的地区,可以利用这个特点进行推测。
[Abstract]:Gejiu tin-copper polymetallic mining area has a history of more than one hundred years. Many experts and scholars at home and abroad have made detailed research on Gejiu from various aspects. Relevant research results are also very rich. Skarn-type sulfide deposits and interlayer oxide deposits are several types of deposits, but not enough attention has been paid to altered granite-type deposits, lamprophyre-related deposits and exhalative deposits. Gejiu tin-copper polymetallic deposit in Yunnan Province is very obvious.The spatial distribution of the deposits is characterized by surface placers, interlayer oxidation deposits, SKARN-TYPE sulfide deposits in contact zones, and copper polymetallic deposits related to altered granite in the intrusive bodies discovered in Laochangdong in recent years. From the origin of magmatic hydrothermal origin to submarine hydrothermal exhalation origin, and then to multi-stage, multi-source and multi-genetic compound deposits are increasingly recognized. With the deepening of understanding and the discovery of new types of deposits, the genetic diversity of Gejiu deposits is constantly enriched. Since the question was put forward, the predecessors have done some research on the metallogenic diversity of Gejiu tin-copper polymetallic ore district in Yunnan. But with the discovery of new deposits in recent years and the improvement of further research, the metallogenic diversity and mineral deposit genealogy of Gejiu area need to be further improved. The theory of "triple" quantitative metallogenic prediction put forward by Da et al. is based on geological anomalies, metallogenic diversity and mineral deposit genealogy. The analysis of geological anomalies is the basis, the study of metallogenic diversity and the characteristics of mineral deposit genealogy is the guidance, and the information and characteristics of various mineralization are based on it. To strengthen the correlation between these three studies, we can clearly understand the causal relationship, geological anomalies (causes) - metallogenic diversity (manifestations) - mineral deposit genealogy (manifestations). It is ultimately to analyze the characteristics of metallogenic diversity in a certain place, and on this basis to establish a mineral deposit genealogy, and to predict the right. In this paper, the characteristics of metallogenic diversity of the main metallogenic types in Gejiu tin-copper polymetallic ore district, Yunnan Province, including metallogenic epoch, distribution space, source of metallogenic materials and genetic types of the deposit are analyzed. Based on the analysis of the characteristics of metallogenic diversity, the time-series, space-series and "time-space-cause" comprehensive spectrum of the deposits in Gejiu tin-copper polymetallic ore district are established respectively. In the last two steps of the "5P" quantitative metallogenic prediction method, the potential of the main metal mineral resources in the east mining area of Gejiu area is quantitatively predicted and evaluated, and the prospecting prospects of the deep part of Gejiu Laoka rock mass similar to Xiao copper polymetallic deposit are also discussed. The main understanding obtained in this paper is as follows: 1. The frequent magmatic activities and tectonic movements in Gejiu area, Yunnan Province, make the metallogenic geological conditions complex and form a variety of tin-copper polymetallic mineral resources in Gejiu area, which provide a basis for the study of metallogenic diversity. The characteristics of metallogenic diversity in Gejiu area of Yunnan Province are analyzed in terms of mineral sources and genetic types. 2. On the basis of analysis of metallogenic diversity and combined with predecessors'research results, four metallogenic series are divided according to metallogenic epoch and ore-bearing formation. Rare, radioactive and non-ferrous metal-nonmetallic minerals related to Yanshanian alkaline rocks are found. Bed metallogenic series (I) rare, nonferrous and noble metal deposits related to Yanshanian granites (II), nonferrous and noble metal deposits related to Yanshanian porphyry veins (III), and rare, nonferrous and noble metal deposits related to Himalayan continental sedimentation and supergene transformation (IV). Among them, series I-III Series IV is the product of late Yanshanian magmatic-hydrothermal endogenetic mineralization. The altered granite-type copper polymetallic deposits are divided into series II, the rare, non-ferrous and noble metal mineralization Subseries (II-1) 3, which are related to the high temperature hydrothermal solution of post-magmatic gasification of granite. On the basis of the characteristics of metallogenic diversity in the polymetallic ore area, the time-space-genetics and the time-space-genetics of the deposits are summarized and established. The main metallogenic epoch of Gejiu tin-copper polymetallic ore area is late Yanshanian, accompanied by regional magmatic activity and tectonic movement, the large-scale metallogenic process begins, forming magmatic stage. Posterior hydrothermal deposits and other related metallogenic types. There were weathering-sedimentary mineralization on a certain scale in Himalayan epoch, represented by interlayer oxidation deposits and various tin placer deposits. The spatial distribution characteristics of ore bodies in inner contact zone, normal contact zone, outer contact zone of rock mass and surface are roughly shown as element zoning characteristics of Be-W, Sn (Cu, Mo, Bi, Be) -Sn, Pb, Ag-Pb, Zn. Taking metallogenic epoch, genetic type as ordinate, and spatial distribution of ore deposits in metallogenic dense area as abscissa, Gejiu tin-copper polymetallic ore deposit is established. Finally, comparing the "time-space-cause" comprehensive genealogy of tungsten-tin polymetallic deposits in southeastern Yunnan, the deposit genealogy is compared in different scales. 4. Xiao copper polymetallic ore body occurs in the altered rock zone of granite margin facies within the rock mass, which is in a special position where the rock mass morphology is slowed down by steep change. The average content of Cu and Sn in the ore body is about 1.79% and 0.51% respectively. Metallogenesis is closely related to alteration. There are many types of wall rock alteration in the deposit. Among them, the alteration types closely related to mineralization are potassium feldspar, fluorite and electrification. According to the symmetry, the main alteration types are divided into two major alteration zones: the potassium feldspar zone and the epidote zone, in which the potassium feldspar zone is obviously mineralized. According to the shape of ore bodies, the spatial distribution of alteration zones and the sudden change of contact between alteration zones, it is speculated that the space of ore bodies is likely to be the passage of ore-bearing hydrothermal migration and mineralization under filling and metasomatism. Typical metallogenic types of ore deposits in major polymetallic ore fields include interlayer oxidation deposits, SKARN-TYPE sulfide deposits in contact zones, metabasalt-type sulfide deposits and altered granite-type copper-polymetallic deposits. Trace elements and rare earth elements in ore of ore-forming type deposits are taken as research objects. The geochemical characteristics of ore-forming elements and their associated elements, correlation of trace elements, characteristics of rare earth elements and characteristic values of elements are mainly analyzed and compared. 6. Similarly, four types of ore-forming types are selected, mainly the contents of ore-forming elements in ore deposits. The spatial distribution of the deposits of the same metallogenic type in different sections of the orefield, the elevation distribution of the contents of copper and tin, the magnitude of the content value, the distribution of the high value interval, and the vertical variation of the content of the metallogenic elements are analyzed and compared. 7. The analysis of metallogenic diversity. On the basis of the establishment of metallogenic pedigree, combining with the research degree of Gejiu area in Yunnan Province and the relevant data collected, the "5P" quantitative metallogenic prediction method is used to quantitatively evaluate the eastern Gejiu area. The ore-forming potential of this deposit is the Western target area (II), the Zhuyeshan target area (IV) and the southern target area (V) of Dabaiyan. Secondly, the prospecting prospects of the deep part of Gejiu Laoka rock mass similar to Xiao copper polymetallic deposit are evaluated. Various trace elements such as Cu, Sb, Bi, Pb, Sn, Cd and Be, which have different anomaly characteristics at the corresponding positions at the top of the deep orebody, can be judged by the anomaly characteristics of the primary halos of various trace elements in the tunnels of different middle sections. Some elements, such as Sr and Ba, are characterized by the distribution of primary halos, which can be used to predict the areas where the rock mass interface can not be obtained by conventional methods.
【学位授予单位】：中国地质大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P618.2

【参考文献】