【作者】 普传杰；

【导师】 秦德先； 王吉坤；

【作者基本信息】 昆明理工大学 ， 矿产普查与勘探， 2006， 博士

【摘要】 云南潞西上芒岗金矿位于西南“三江”地区怒江以西高黎贡山构造-岩浆-变质-成矿带上,是近年在“滇(中国云南)缅(缅甸联邦)”相邻地区首次发现的一个卡林型金矿床。矿区所处的经向展布的高黎贡山成矿带,被认为是一条重要的铁、铜、铅、锌、钨、锡、金、银多金属成矿带,同时又处在西南“三江”成矿带上,理应成为我国西部矿产资源开发的重要区域之一。但由于区内已有的基础地质和矿产地质研究程度薄弱,目前已探明的矿产资源量与其巨大的资源潜力极不相符,近年来对矿区及外围地区乃至整个成矿带的找矿方向不明确,后备资源地和资源潜力眉目不清。前人少量的工作认为,区内矿床是严格受不整合面控制的中低温热液型矿床,或认为浅表部红色粘土型金矿是矿区的找矿主体,对该区进一步找矿均具有明显的束缚作用。因此,针对滇西“三江”地区最困难地段,应用新理论、新方法、新技术,系统地对上芒岗金矿区“卡林型”和“红色粘土型”金矿床进行解剖研究,查清矿床的成矿地质条件及矿化富集规律,分析总结各种控矿因素和成矿作用之间的关系,重新观察分析和审视该区金矿床(体)的时空定位机制和成因机理,完善和建立成矿模式,进而指导矿区及外围地区找矿,不仅可以丰富和完善该类矿床的地质认识,在“三江”地区全面研究“卡林型”金矿床提供一个典型范例,拓展找矿途径和工作思路,而且有利于扩大矿区及外围资源潜力和提高高黎贡山成矿带的矿产地质研究水平。本文在重新审定区域地质背景的基础上,研究了上芒岗金矿区内不同类型金矿床(体)的矿床地质特征、矿石矿物学、岩(矿)石的微量元素、稀土元素和稳定同位素地球化学及流体包裹体等,在总结控矿规律的基础上,系统分析了其成矿作用,建立了成矿模式,结合X荧光测量、γ能谱测量、氡气测量、地电化学和地球化学勘查等应用地球化学勘查方法的技术成果,对矿区及外围地区进行了成矿预测,提出了找矿远景区和优选靶区。本研究获得如下结论和认识:(1)矿区处于冈瓦纳古陆和欧亚大陆碰撞汇聚结合带东部边缘的构造转换活动区的次级伸展构造单元内,是掸邦地块北西边缘的高黎贡山金银多金属成矿带南东部龙陵—瑞丽断裂带中段之次级的潞西金矿成矿带的组成部分,中一新生代以来长期受到印度大陆不断向欧亚大陆的强烈推挤、碰撞、俯冲和造山作用过程的影响,使本区成为一个中—新生代褶皱带或推覆带或陆缘活动带,局部具有被卷入陆内再次造山的变质地体性质。(2)区内陆内造山带的形成与演化既取决于新生代印度板块向欧亚板快的碰撞及其持续挤入,又与晚古生代以来特提斯洋盆构造演化的主要控制作用密切相关。因而,晚古生代和新生代时期表现出的独特动力学过程,使高黎贡山金银多金属成矿带具有发生大规模成矿作用的重要构造背景,具有卡林型、红色粘土型、韧性剪切带型和现代热泉型等金矿床的成矿条件。(3)矿区存在原生卡林型和红色粘土型两类矿体。从微量元素地球化学和稀土元素地球化学特征看,红色粘土型金矿床成矿物质来源于原生卡林型金矿或金矿化蚀变体,是原生金矿在氧化带中的表现,二者紧密联系,不可分割。系统全面的深入研究表明,红色粘土型金矿仍属“红土型”金矿床,与国内外“红土型”金矿床有很多相似之处,但也存在较大差异,定名为“红色粘土型”金矿,更能反映其特点。(4)系统总结了美国西部和中国两个“金三角”卡林型金矿床的普遍特点,并将其与上芒岗金矿进行比较研究。上芒岗金矿在矿床地质特征、控矿构造、矿化蚀变和围岩蚀变等地质地球化学特征上与它们具有基本相似的特征,从而肯定了上芒岗原生金矿属卡林型金矿床的认识。原来认为卡林型金矿床主要赋存于中侏罗统勐嘎组碎屑岩与下二叠统沙子坡组碳酸盐岩的不整合面上。通过系统的矿床地质、矿石矿物学、岩(矿)石的微量元素、稀土元素、稳定同位素地球化学和流体包裹体等研究,提出下伏沿上芒岗断裂破碎带向北西倾斜的深部勐嘎组和沙子坡组碳酸盐岩及碎屑岩内均可赋存卡林型原生金矿床,突破了上芒岗金矿区“不整合面控矿”的思路。(5)除近地表产出的红色粘土型金矿床外,根据金矿体赋矿建造的空间结构,卡林型金矿体空间上从上到下依次展布侏罗系中上部及侏罗系与二叠系之间不整合面的似层状马脖子式矿体、北东向断裂带中的脉状上芒岗式矿体、公养河群顶板之上二叠系中下部的细网脉状营盘式矿体,以及赋存在深部隐伏斑岩接触带附近的曲面状弄丘坝式矿体等四种主要矿床式,并共同构成集束状、楔柱状、叠层状、曲透镜状或不规则状和树枝状或花状等五种组合型式。(6)建立了上芒岗金成矿带“红色粘土型”、“卡林型”两种类型金矿床的成矿模式,即:在晚侏罗世—晚白垩世早期,板块对挤、碰撞及俯冲激发深部地幔物质熔融上涌侵位,结晶分异后与地壳物质发生强烈的同化混染联合作用(AFC过程),形成的深部幔源成矿流体沿龙陵—瑞丽韧—脆性剪切断裂带运移,并在与其平行的上芒岗、马脖子等次级断裂破碎带中运移富集沉淀,燕山晚期形成了卡林型金矿,构造变形转折部位和走滑断裂的拉分区域是金矿化的富集位置。喜马拉雅期印-亚大陆碰撞造山过程在本区应有明显的体现,与之有关的成矿作用应做进一步的深入研究。卡林型金矿作为矿源,在沙子坡组碳酸盐岩的岩溶地貌基础上,晚第三纪至第四纪由于岩溶崩塌作用,成矿物质短距离搬运和堆积,再经风化淋滤作用,形成了“红色粘土型”金矿床,其形成与“矿胚”、气候、构造抬升的速度和地形等因素密切相关。但红土化作用不完全,去硅作用不彻底,氧化作用较弱,红土化作用只达到粘土化阶段,即红土化的初级—中级阶段,是本区红色粘土型金矿床成矿作用的典型特征。(7)提出了龙陵—瑞丽深大断裂带是深部幔源成矿流体运移的通道,与其平行的次级断裂破碎带既是成矿流体运移的通道,又是有利的卡林型金矿赋矿空间,沿上芒岗断裂破碎带及与之平行的断裂带深部均是寻找矿卡林型原生金矿的重点,而在卡林型原生矿附近的微型盆地则是寻找红色粘土型金矿靶区。(8)在上述成矿模式、矿床结构模型及控矿规律认识的指导下,结合地球化学勘查成果,综合区内生产实际,进行了成矿预测,提出了上芒岗金矿区深部、勐莫—崃巴山、回龙村—项球、河边寨、马脖子等五个成矿预测远景区,并进一步圈出广令坡矿段、麦窝坝矿段、勐莫和红球河等四个优选靶区。其中,广令坡、麦窝坝两个预测靶区以找寻深部的卡林型金矿为主,近地表部位仍有扩大红色粘土型金矿资源量的前景;勐莫预测靶区以寻找红色粘土型金矿为重点;红球河预测靶区除存在一定规模的卡林型和红色粘土型金矿外,还有寻找韧性剪切带型金矿的潜力。更多还原

【Abstract】 The Shangmanggang gold deposit is located in Gaoli-Gongshan tectonic-magmatic metallogenic belt,western Nujiang river within the "Three-River region".It was the first Carlin-type gold deposit found in the neighboring area between Yunnan and Burma.The Gaoli-Gongshan metallogenic belt located in the "Three Rivers" tectonic-magmatic belt of western Yunnan and strikes north-south,and iron,copper,lead,tungsten,tin,gold,silver and polymetals mineralization occurs.Therefore,it should become one of the key mineral resource development areas.However,duing to the poor work on the basic geology and mineral exploration in this belt during the past years and recently,the proven mineral resource is far less than the predicted mineral potential.Now,it is still unclear for the prospecting target in this belt as well as beyond this region and not sure how much mineral resources and resource bases in this region.The previous geological work indicated that the deposit in this belt is mesothermal type deposit strictly controlled by the unconformity.And or laterite type gold deposit is the key target in this belt that confined the further exploration.Therefore,it is significant valuable for applying the new prospecting theory,new method and new technique to the mineral exploration in the most complex area of this "Three-River" belt.Through the systematic and detailed study on the Carlin-type Shangmanggang gold deposit and the reddish clay-typegold deposit,it will help to identify the ore-controlling conditions and the polymetals mineralization enriching rules,analyze and summarize the relationship between various of ore-controlling factors and the mineralization process,re-observe and analyze the temporal and spacial deposition process of gold deposits(orebodies),integrity and build the gold deposit model.Further more,it will guide outlining of the prospecting potential in the deposit area and the surrounding areas.This not only deepens the newly geological cognition for this type of gold deposit,but also provide a typical example for discovering and studying this kind of Carlin type gold deposit in "Three Rivers" belt,and widen prospecting routes and exploration plan.As a result,it will increase the potential resources in the deposit area and the surrounding areas in this belt.The geological characteristics,mineralogy,trace elements,rare earth elements,stable isotope geochemistry and fluid inclusions of different types of gold deposits in the Shangmanggang gold deposit area was studied respectivly on the basis of recognizing regional metallogenic background in this paper.Based on the summarization of ore-controlling rules,the metallogenic process was analyzed systematically also,and the metallogenic model of gold deposits was built.After applying multi-prospecting techniques for the studied area,such as X-fluorescence measurement,γ-energy spectrometry measurement,radon gas measurement,geo-electrochemical and geochemical survey,the author conducted the metallogenic prognosis in the Shangmanggang gold deposit area as well as its surrounding areas.Furthermore,the author proposed potential prospecting areas and preferred prospecting target areas.The research achievement and conclusions are as follows:1.The Shangmanggang gold deposit is located in the secondary extensional tectonic unit within active tectonic conversion area,eastern edge of the collision and conjunction between Gondwana continent and Euro-Asia continent,which is part of the Luxi gold mineralization zone,middle part of Longling-Ruili fault zone,that is located in the southern part of Gaoli-Gongshan gold-silver polymetals mineralization zone,northweast edge of the Chanbang terrain.Since Mesozoic and Cenozoic times,this area was formed to the Mesozoic-Cenozoic fold zone or overriding zone or active structural zone along edge of the continent due to the continuous intensive pushing,colliding,subducting and orogenesis of the India continent to the Euro-Asian continent,locally it was evolved into the intra-continent meta-terrain.2.The formation and evolution of this intra-continent orogenesis belt not only depends on the collision and continuous squeezing of Cenozoic India plate into Euro-Asian plate,but also is closely associated with main tectonic control of Late-Paleozoic Tethys ocean basin evolution.Therefore,the unique dynamic process in Late-Paleozoic and Cenozoic times results in the formation of significant tectonic setting which controls Gaoli-Gongshan gold-silver multi-metals mineralization zone,and thus forms preferred ore-forming conditions for the Carlin-type,Reddish Clay-type,ductile-shear zone type and modern hot spring type gold deposits in this belt.3.Main gold deposit types are Calin-type and Reddish Clay-type in this deposit area. From characteristics of trace elements and REE geochemistry of gold deposits,it showed that the reddish clay-type gold deposit is derived from the Carlin-type gold deposit,i.e.,the representation of Carlin-type gold orebody in the oxidized zone,both are closely associated. Based on the systematic study on this reddish clay-type deposit,it was found that this type of gold deposit has lots of similarity with the worldwide so-called "Laterite-type" gold deposit,but there is still big difference between these two kinds of gold deposits.Therefore, in this paper,the author names this kind of gold deposit after the reddish clay-type gold deposit in order to reflect its specific characters.4.On the basis of summarizing systematically general characteristics of Carlin-type gold deposits in the western USA and Yunnan-Guizhou-Guangxi gold triangle areas and Sichuan-Gansu-Shanxi gold triangle areas,the author conducted the comparison between the above-mentioned Carlin-type gold deposits and the Shangmanggang gold deposits in aspects of ore deposit characters,ore-controlling structures,mineralization and alteration etc.,it was found there are great similarities between among them in geology and geochemistry.Therefore,it is concluded that the Shangmanggang gold deposit is a Carlin-type gold deposit indeed.Previously it was believed that the Shangmanggang gold orebody was mainly located in the unconformity plane between Middle-Jurassic Mengga Fm.elastic rock and Lower-Permian Shazipo Fm.carbonate rocks.Through the systematical research on deposit geology,ore mineralogy,trace elements of ore and wall rocks,rare earth elments stable isotope geochemistry and fluid inclusion,the author proposed a new prospecting clue,i.e.,the Carlin-type gold orebody in the Shangmanggang deposit area,also located in the NW-dipping Mengga Fm.and Shazipo Fm.carbonate and clastic rocks in the depth along the Shangmanggang fault zone,which widened the previous gold mineralization controlled by the unconformity in the Shangmanggang gold deposit area.5.Except the reddish clay-type gold deposit which occurred in the sub-surface,the Carlin-type gold deposit in this area can be classified into the following four types from the upper to the lower level based on the spatial distribution of gold orebodies,that is,(a) Mabozi-type bed-like gold orebody that occurred in the unconformity between Upper -Middle Jurassic and Permian strata,(b)Shangmanggang vein-type gold orebody that controlled by the NE-trending fault,(c)Yingpan-type veinlets gold orebody that is located in the Middle-lower part of Permian strata,upper of the Gongyanghe Group hangingwall,and (d)Nongqiuba-type curved gold orebody that is located in the contact zone of the deep concealed porphyry.The above-mentioned four types of gold orebodies form five types of spatial association,i.e.,clustered,wedged,stromatolited,irregular and branched or anthus-like.6.The metallogenic models of the "Reddish clay-type" and the "Carlin-type" gold deposits in the Shangmanggang gold mineralization zone was built,i.e.,during a period of Late Jurassic to early Late Cretaceous,the deep mantle-source materials melt and upwelled due to plate press,collision and subduction.Then,the assimilation and mixture process took place between the crystallized and differentiated mantle-source materials and crust materials, and this resulted in the formation of deep mantle-source ore-forming fluids.This kind of ore-forming fluid transported along regional Longli-Ruili ductile-brittle fault zone and deposited in the secondary faults-Shangmanggang fault and Mabozi fault and some others which are parallel to Longlin-Ruili fault,and thus formed the Carlin-type gold deposit in Late Yanshanian period.The gold mineralization is enriched in the transitional part of structural deformation and extensional part of the slipping fault.Theoretically,the dynamitic process of tectonic collision between Indian plate and Asian Plate should have apparently influence in this area during Himalayan period,the mineralization associated with that tectonic movement needs to do further research.The above-mentioned Carlin-type gold deposit provided the source for the formation of the reddish clay-type gold deposit.During the period from Late Tertiary to Quaternary,on the basis of Shazipo formation carbonate karst,the ore-forming matter was transported short distances and re-deposited due to the karst slumping(cave collapse).After weathering and leaching,the "reddish clay-type" gold deposit was formed,which is closely associated with the original Carlin-type gold deposit,climate,tectonic uplift speed and terrain.This kind of "laterite" process is not completely one,i.e.,not fully de-silica process and weak oxidization. Therefore,it only reaches the clay-forming stage,i.e.,early and middle stage of "laterite" process.7.The author further pointed out that the deep and large-sized Longling-Ruili fault zone is a channel for the deep mantle-source ore-forming fluid transportation,and the secondary faults that parallel to Longling-Ruili fault are not only channels for ore-forming fluid transportation,but also favorable space for the Carlin-type gold orebodies.Thus,the main prospecting target area for the Carlin-type gold deposit is located in the deep part along Shangmanggang fault zone,and for the reddish clay-type gold deposit is located in the small-size basin nearby the Carlin-type gold deposit.8.Based on the built metallogenic models,physical model of gold deposits and the summarized ore-forming rules,in combination with geochemical exploration achievement and integration of the productive data in the studied area,the outlining of five metallogenic and prospecting areas,such as the deep part of Shangmanggang gold deposit area, Mengmo-Laibashan,Huilongcun-Xiangqiu,Hebianzhai and Mabozi were carried out.In more details,the author further proposed that the Guanglingpo ore section,Maiwoba ore section,Mengmo and Hongqiuhe are preferred targeting areas.In the Guanglingpo and Maiwoba sections,the prospecting target is the Carlin-type gold orebody at depth,and nearby the surface,there is still potential prospects for enlarging the reddish clay-type gold deposit.In the Mengmo area,the main prospecting target is the reddish clay-type gold deposit.And in the Hongqiuhe area,the prospecting targets are the Carlin-type gold deposit as well as the reddish clay-type gold deposit.Moreover,there is a potential for prospecting the ductile-brittle type gold deposit.更多还原