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东伙房金矿位于内蒙古武川县,为一小型金矿床,属于与浅成花岗斑岩有关的中浅成中高温热液矿床。本次成矿预测思路为:在已知1放体及其他含金变带上,建立大量的观测点,把每个观测点的地质,地球物理,地球化学,矿物学等方面的成矿信息分析研究,并把1号矿体作为已知矿体,总结1号矿体的成矿信息特征,建立接近于客观实际的已知矿体模型,用之与其他含金蚀变带进行了对比,从而观测出成矿的有利地段,作者把以上这种工作方法称 相似文献
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文章通过对东准噶尔蒙西矿床蚀变、矿化和元素分带特征的研究,厘定了蚀变类型及其时空分布规律,探讨了两期矿化蚀变所对应的斑岩体,初步建立了矿床成矿模型。结果显示蒙西斑岩铜矿区蚀变与成矿具双系统叠加结构:地表和浅部的钾化和铜钼矿化与花岗斑岩密切共生。矿区大面积绢英岩化-黄铁矿化-青磐岩化、深部发育的钾化磁铁矿化,及从上往下的Ag、Pb-Zn与Au垂向分带的矿化与深部发育的闪长玢岩有关。地表和浅部花岗斑岩及其伴生的钾化、铜钼矿化是花岗斑岩铜钼矿化蚀变系统的根部与残留,而闪长玢岩成矿系统以铜金矿化为特征。基于新建立的成矿模型与已有的勘探成果,推测深部存在隐伏的Cu-Au矿体。 相似文献
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乌奴耳矿床位于内蒙古东部大兴安岭造山带中段中生代火山岩覆盖区,为近年来新发现的陆相火山岩型多金属矿床.为了对该矿区的进一步深部找矿勘查工作提供围岩蚀变和岩石地球化学信息,对乌奴耳矿床进行了详细的野外地质特征研究、岩石蚀变分带研究和原生晕研究.乌奴耳矿床中存在多期多阶段矿化特征:第1阶段斑岩型钼矿化,主要产于矿床深部的花岗斑岩体内;第2阶段岩浆热液(隐爆角砾岩)型铅锌矿化,主要产于花岗斑岩体顶部及其附近围岩的隐爆角砾岩中;第3阶段浅成低温热液型铅锌银矿化,主要产于浅部张性断裂构造中.矿区内存在至少两期与成矿关系密切的构造事件,张性断裂构造是重要的控矿因素和找矿标志.乌奴耳矿床中具有明显的围岩蚀变分带特征,蚀变矿物分布与已知矿体产状具有较好的对应关系,是重要的找矿标志之一.岩石原生晕异常分布与已知矿体具有较好的对应关系,具有明显的前缘晕-近矿晕-尾晕元素组合分带特征,能够为乌奴耳矿床深部找矿提供可靠信息.综合以上主要找矿信息特征,预测在乌奴耳矿床Ⅱ矿段207勘探线剖面深部有盲矿体存在. 相似文献
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喇嘛朝鲁图铜钼矿床是近几年在蒙古国东部发现的一处中型斑岩型矿床.该矿床的形成与华力西晚期、燕山期的构造、岩浆活动关系密切,具有较明显的叠加成矿特征.通过对矿床成因、地球化学特征、蚀变带分带特征及矿化特征等进行综合对比分析,将该斑岩型矿床与南部的查布浅成中低温热液脉型铅锌银矿床归纳为一个统一的矿床成矿系列,初步建立了斑岩型-浅成中低温热液脉型成矿模式,在此基础上对矿区及其外围进行了成矿预测. 相似文献
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黑龙江省东宁县金厂金矿是滨太平洋成矿域浅成低温-斑岩成矿系统中极具代表性的特大型金矿床。矿区已发现爆破角砾岩筒型、环状一放射状裂隙充填型、似层状微细脉浸染型和断控构造破碎带蚀变岩型等矿化类型。为确定成矿时间,作者应用高精度单颗粒激光熔蚀氩氩法,选择Ⅻ号破碎带蚀变岩型矿体中多金属硫化物一石英脉中石英和J-9号爆破角砾岩筒型矿体中闪锌矿进行年龄测定。获得Ⅻ号矿体石英40Ar/39Ar等时线年龄为119±5Ma(MSWD:6.3),J-9号矿体闪锌矿40Ar/39Ar等时线年龄为129±0.8Ma(MSWD=3.7),限定了成矿作用的上限。结合最新获得的相关成矿地质体精细年代学成果,进一步认定金厂金矿成矿时代为燕山晚期,成矿与同时代闪长玢岩一花岗闪长斑岩关系密切。金厂金矿成岩、成矿环境具备寻找富金斑岩型铜矿的有利条件,与成矿关系密切侵入岩呈岩脉、岩枝状,指示矿区剥蚀程度浅,深部还有发现斑岩型Au(cu)矿化的可能。 相似文献
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黑龙江永新金矿床的发现是多宝山矿集区外围地质找矿取得的一项新成果.矿床赋存在早白垩世火山盆地与古生代糜棱岩带接触地带的一个浅成相和潜火山岩相小侵入体及岩脉密集分布地段.潜火山相的潜英安岩、潜流纹岩等形成于成矿前或成矿期,受蚀变矿化;浅成相的花岗斑岩、闪长玢岩等形成于成矿后,破坏矿体.金矿体及矿化主要赋存在隐蔽爆破作用形成的蚀变角砾岩体中,其次赋存在蚀变角砾岩体外侧的糜棱岩类围岩中.该矿床的发现显示在黑龙江省西部的古生代糜棱岩带中存在与早白垩世火山作用有关的潜火山热液型金矿,也表明黑龙江多宝山斑岩铜矿老矿区的外围仍具有找矿潜力. 相似文献
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商城汤家坪钼矿是近年在大别山地区探明的一处大型钼矿床。该矿区地球化学异常特征研究表明,成矿元素含量变化与花岗斑岩体空间位置、岩石类型、蚀变特征密切相关;在三度空间内,地球化学异常的分布严格受斑岩体控制;Mo异常浓度分带清晰,其内带指示了钼工业矿体位置,中带反映了边界矿体和强矿化范围,外带反映了弱矿化和矿化蚀变范围。在对成矿地质背景、指示元素地球化学参数和地球化学异常特征分析研究的基础上,建立了地质、地球化学找矿标志。 相似文献
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金矿是班公湖-怒江成矿带的优势矿种之一。由于地质工作程度总体较低,金矿的成矿规律和成矿作用研究相对薄弱,严重制约了金矿的评价。本文在前人已有研究成果的基础上,通过大量的野外地质调查与综合研究成果,初步论述了班公湖-怒江成矿带金的成矿地质背景、金矿床的主要成因类型、时空分布特征和成矿作用。研究结果表明,班公湖-怒江成矿带金矿床(点)在空间分布上具有东西成带,相对集中的分布特征。金主要以共生、伴生的形式存在。矿床类型有矽卡岩型、斑岩型、造山型和浅成低温热液型等4类,其成矿时代集中于晚侏罗世—晚白垩世。依据矿床成因及成矿作用主控因素,可将班公湖-怒江成矿带金矿床归纳为与洋壳俯冲消减作用有关的岩浆热液金成矿系统和与大陆碰撞造山作用有关的金成矿系统。与洋壳俯冲消减作用有关的岩浆热液金成矿系统可进一步划分出浅成低温热液型金矿床、斑岩型铜金矿床、矽卡岩型金铜矿床等3种成因类型;而与大陆碰撞造山作用有关的金成矿系统包括浅成低温热液型铜金矿床、造山型金矿床、矽卡岩型金铜矿床等3种成因类型。 相似文献
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阿希金矿主要蚀变类型及其与金矿化关系 总被引:17,自引:2,他引:15
阿希金矿床赋存于下石炭统大哈拉军山组陆相火山岩中,成矿与破火山口(火山机构)环状断裂构造系统有关,属典型的冰长石-绢云母型大型金矿.阿希金矿近矿围岩蚀变为硅化、绢云母化、冰长石化、叶腊石化、绿泥石化等,以主矿体为中心向两侧共划分出6个蚀变矿物组合带,其中强硅化带和绢英岩化带与金矿化关系密切. 相似文献
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马坞金矿分布于岷-礼成矿带的东部,通过野外地质勘查和1/万土壤地球化学测量,获得了丰富的矿体地质及地球化学测量数据,系统分析了矿床的地球化学特征,围岩蚀变以中-低温热液蚀变为主,蚀变强度与金矿化程度呈正相关,从地质的地层、构造、岩浆岩及地球化学特征方面分析了控矿因素,对找矿潜力进行了分析. 相似文献
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In Zhangbaling Tectonic Belt,two types of mineralization,auriferous quartz veins and alteration halos,can observed within many deposits.The pressure of metallogenesis of auriferous alteration halos is much higher than that of quartz vein,the temperatures of metallogeneses of these two types of orebodies are don't the same Geochemistry study indicates that both of them are micro-mesothermal deposits related to Yanshanian granites.The results of proton microprobe analysis of sulphides from the gold deposits in the area show that the "invisible" gold existed in sulphides is in the form of micro inclusions,and the concentration of "invisible" gold in sulphide minerals within quartz vein is poorer than that from alteration halos.Field observation shows that the structural modality of the fractures controlling the orebodies of auriferous quartz vein is different from that of the auriferous alteration zones.The fracture controlling the orebodies of auriferous alteration halos is compress-shear fracture,auriferous quartz vein is controlled by extensive fault.The alteration halos crosscut by auriferous quartz vein.The wallrocks of the former altered strongly and developed alteration zones well.The wallrocks of auriferous quartz vein altered slightly.The results of tectonogeochemical study shows that the concentration of associated metallogenesis elements and intensity of alteration are positively correlated with tectonic deformation strength for auriferous alteration halos.It indicates that it is probably a general character for micro-mesothermal gold deposits due to the multistages of metallogeneses took place.The tectonic environment is the most important fact determining the mechanism of fluid flow and precipitation of gold,and then the types of mineralization and modes of gold. 相似文献
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Copper mineralization along the Mount Gordon Fault Zone in northwest Queensland contains sufficient mercury to permit mercury pathfinder techniques to be used for exploration for further deposits in the area. At the Mammoth mine, the No. 1 orebody contains 310–14000 ppb Hg, with the highest contents in “sooty chalcocite” which may be of supergene origin. The B orebody contains 100–4300 ppb Hg, with highest concentrations at the top of the deposit. Other deposits in the Mammoth area contain 10–1600 ppb Hg, with mean mercury contents > 200 ppb in fault-related mineralization.There is a strong positive correlation between mercury and copper, sulfur, silver, arsenic, bismuth, lead, antimony and thallium contents in the deposits which suggests mercury was introduced during the mineralizing process. However, most of the mercury occurs on the surfaces of sulfide minerals, indicating its introduction at a late stage of mineralization.Mercury in the No. 1 orebody is partly of supergene origin whereas primary mineralogy may control mercury distribution in the B orebody. The presence near the Mammoth Fault of a lens of pyrite containing high concentrations of mercury (geometric mean 820 ppb) suggests that the mercury content of pyrite encountered in future exploration programmes in the region might be used to indicate proximity to mineralized fault zones.Gossans derived from copper deposits contain more than five times the amount of mercury in ironstones developed over unmineralized or poorly mineralized fault zones. The mercury contents of iron-rich rocks may be used to discriminate gossans from the numerous fault ironstones in the Mammoth area. 相似文献
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The Lapa gold deposit contains reserves of 2.4 Mt at 6.5 g/t Au and is one of the few deposits located directly within the Cadillac–Larder Lake Fault Zone (CLLFZ), a first-order crustal-scale fault that separates the Archean Abitibi Subprovince from the Pontiac Subprovince to the south. Gold mineralization is predominantly hosted in highly strained and altered, upper greenschist–lower amphibolite facies mafic to ultramafic rocks of the Piché Group. Auriferous ore zones consist of finely disseminated auriferous arsenopyrite–pyrrhotite?±?pyrite and native gold disseminated in biotite- and carbonate-altered wall rocks. Native gold, which is also present in quartz ± dolomite–calcite veinlets, is locally associated with Sb-bearing minerals, especially at depth ≤1 km from surface where the deposit is characterized by a Au–Sb–As association. At vertical depth greater than 1 km, gold is associated with arsenopyrite and pyrrhotite (Au–As association). The mineralogy and paragenesis of the Lapa deposit metamorphosed ore and alteration assemblages record the superposition of three metamorphic episodes (M1, M2, and M3) and three gold mineralizing events. Spatial association between biotitized wall rocks and auriferous arsenopyrite indicates that arsenopyrite precipitation is concomitant with potassic alteration. The predominant Au–As association recognized across the deposit is related to gold in solid solution in arsenopyrite as part of a pre-M2 low-grade auriferous hydrothermal event. However, the occurrence of hornblende?+?oligoclase porphyroblasts overprinting the biotite alteration, and the presence of porous clusters and porphyroblasts of arsenopyrite with native gold and pyrrhotite indicate an auriferous metasomatic event associated with peak M2 prograde metamorphism. Late retrograde metamorphism (M3) overprints the hornblende–oligoclase M2 assemblage within the host rocks proximal to ore by an actinolite–albite assemblage by precipitation of free gold and Sb–sulfosalts at lower P–T. The complex relationships between ore, structural features, and metamorphic assemblages at Lapa are related to the tectonometamorphic evolution of the Cadillac–Larder Lake Fault Zone at different times and crustal levels, and varying heat and fluid flow regimes. The Lapa deposit demonstrates that early, low-grade gold mineralization within the Cadillac–Larder Lake Fault Zone has benefited from late gold enrichment(s) during prograde and retrograde metamorphism, suggesting that multi-stage processes may be important to form gold-rich orogenic deposits in first order crustal-scale structures. 相似文献
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《International Geology Review》2012,54(7):882-893
The Yangjingou gold deposit in Jilin Province lies 11 km south of the large-scale Xiaoxinancha gold–copper deposit. Yangjingou orebodies are structurally controlled fault- or fracture-related auriferous quartz veins. This type of mineralization is significantly different from that of the Xiaoxinancha porphyry gold–copper deposit, and has mineral assemblages and fluid inclusion compositions typical of orogenic gold deposits. We suggest that the Yangjingou deposit is the first orogenic gold deposit discovered in the Yanbian area, even in all of NE China. Here, we present new isotopic dating and trace element analysis of the ore-hosting monzogranite and auriferous quartz veins within the deposit, in order to determine the age and tectonic setting of metallogenesis, and the geological conditions controlling gold mineralization. LA-ICP-MS U–Pb dating of zircons separated from the monzogranite yielded an age of 262.3 ± 1.3 Ma, indicating intrusion during the late Permian. Hydrothermal muscovite from auriferous quartz veins yielded a 40Ar/39Ar plateau age of 241.57 ± 1.2 Ma, indicating that gold mineralization occurred at 241 Ma. Trace element and REE compositions of the monzogranite and auriferous quartz veins are both indicative of the formation from a region of the upper mantle that previously underwent crustal contamination. Geochronological analysis indicates that the diagenesis and mineralization resulting in the Yangjingou gold deposit occurred during the late Permian–Early Triassic. The tectonic evolution of the region and comparison of this deposit with other mineralizing events indicate that the orebody formed during orogenesis associated with collision between the North China and Siberian cratons. 相似文献