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1.
辽宁东平金矿床地质特征及找矿方向   总被引：1，自引：0，他引：1  
南秦岭南部构造带具备较好的金矿成矿条件与成矿背景，是该区域规模较大金矿带.金沟矿段是黄龙金矿床最主要的组成部分，该矿段矿石中磁黄铁矿和黄铁矿发育，其中磁黄铁矿矿石是矿床中含量最高的硫化物矿石.磁黄铁矿存在两种产出状态，分别为早期形成的呈浸染状、团块状分布的磁黄铁矿与晚期形成的脉状磁黄铁矿.成分分析结果表明以单斜磁黄铁矿为主.该矿床属中-低温矿床.微量元素结果显示富Co贫Ni，与金矿化关系密切.在含金性方面，脉状产出的磁黄铁矿优于团块状分布的磁黄铁矿，且脉体越细含金性越好，因此细脉状磁黄铁矿可作为该区重要的找矿标志.  相似文献   

2.
含铜黄铁矿型矿床包括块状硫化物型铜矿床及别子型矿床。一般认为其形成与海底火山喷气-沉积作用有关。但对这类矿床的认识却存在很多争议。 1.对含铜黄铁矿型矿床的新认识。过去很多人都把这类矿床与块状硫化物矿床联系在一起。近年来作者研究表明,很多这类矿床不仅有块状硫化物矿石,而且还含有浸染状、细脉状、网脉状以及条带状矿石。且这些矿石往往是属同一成因的,因此将这类矿床统统以块状硫化物矿床命名是不符合实际的。比如加拿大Gold-Stream地区与基性火山岩有关的铜锌矿床;其中包含两种矿石,一种是产于绿色和暗色钙质千枚岩中薄层浸染状硫化物矿石,另一种为产于绿岩带地层间隙中的块状硫化物矿石,其间含有磁黄铁矿和黄铜矿的薄层紧密混合  相似文献   

3.
南秦岭南部构造带具备较好的金矿成矿条件与成矿背景,是该区域规模较大金矿带.金沟矿段是黄龙金矿床最主要的组成部分,该矿段矿石中磁黄铁矿和黄铁矿发育,其中磁黄铁矿矿石是矿床中含量最高的硫化物矿石.磁黄铁矿存在两种产出状态,分别为早期形成的呈浸染状、团块状分布的磁黄铁矿与晚期形成的脉状磁黄铁矿.成分分析结果表明以单斜磁黄铁矿为主.该矿床属中-低温矿床.微量元素结果显示富Co贫Ni,与金矿化关系密切.在含金性方面,脉状产出的磁黄铁矿优于团块状分布的磁黄铁矿,且脉体越细含金性越好,因此细脉状磁黄铁矿可作为该区重要的找矿标志.  相似文献   

4.
红海VMS铜锌矿床位于新疆东天山大南湖-头苏泉岛弧带的卡拉塔格地区,矿床上部发育似层状块状硫化物矿体,下部为不整合的脉状-网脉状矿体,块状矿体上盘火山岩盖层中也发育少量铜矿化。本文在前人工作基础上,根据矿物交代次序、脉体穿插关系和矿物共生组合类型,精细划分了矿床的蚀变分带和成矿期次。矿床(含盖层)从浅到深依次发育绿泥石-钠长石-绢云母-碳酸盐化、绿帘石-绿泥石-钠长石-绢云母-碳酸盐化、石英-绢云母-黄铁矿化、块状硫化物矿体、绿泥石-黄铁矿±绢云母化和绿泥石-石英-绢云母化。红海矿床成矿过程可分为VMS成矿期、后期热液叠加期和表生期,其中VMS成矿期可细分为黄铁矿阶段、黄铜矿-闪锌矿阶段和重晶石阶段,后期热液叠加期可细分为钠长石化阶段、绿泥石-绿帘石阶段和石英-碳酸盐阶段。主矿化期及蚀变特征与典型VMS矿床类似,但同时还表现出许多海底交代作用的特征。后期热液在矿体上盘火山岩中所产生的绿帘石化、绿泥石化和绿帘石-石英-黄铜矿-斑铜矿脉、石英-碳酸盐脉等蚀变和矿化,与斑岩矿化系统的青磐岩化类似,表明红海矿床后期可能受到斑岩系统的叠加,矿区具有斑岩铜矿床的找矿潜力。  相似文献   

5.
本文报道了内蒙古狼山成矿带内两个最大的铅锌多金属硫化物矿床——东升庙矿床和炭窑口矿床中黄铁矿、黄铜矿单矿物的铁同位素研究结果。东升庙矿床绢云石墨片岩中不规则状黄铁矿的铁同位素组成δ~(56)Fe_(-IRMM)值在+0.04‰~+1.11‰之间,呈现铁的重同位素富集,指示了海水中的铁以氧化态沉淀并在成岩期转化成黄铁矿的矿化过程。东升庙和炭窑口矿床富硫化物矿石中黄铁矿和黄铜矿的铁同位素组成δ~(56)Fe_(-IRMM)值的变化范围为-1.33‰~+0.08‰,具有热液成矿特征,指示金属成矿物质来源于热液流体。另外,绢云石墨片岩中脉状黄铁矿的铁同位素组成δ~(56)Fe_(-IRMM)值的变化范围为-0.39‰~-0.04‰,处于矿石黄铁矿和围岩不规则状黄铁矿之间,指示脉状黄铁矿是热液矿化的产物,并在成矿过程中混入了围岩中早先形成的富集铁的重同位素的黄铁矿。绢云石墨片岩中广泛发育的不规则状黄铁矿与赋存在绢云石墨片岩中的富硫化物矿体具有完全不同的铁同位素组成,指示热液活动对不规则状黄铁矿没有明显成矿物质贡献,因此同沉积热液活动成矿的可能性不大。结合赋存在白云石大理岩中硫化物矿体的顶、底部常见硅化的白云石大理岩角砾,本文提出后生矿化是东升庙多金属硫化物矿体的主要成矿方式。另外,东升庙矿床和炭窑口矿床的矿石硫化物具有相似的铁同位素组成特征,指示两者的成矿物质来源具有相似性。  相似文献   

6.
安徽铜陵冬瓜山铜(金)矿床成矿模式   总被引：22，自引：11，他引：11  
长江中、下游断裂坳陷带是我国重要的铜、金、铁、硫成矿带,存在一系列块状硫化物矿床及与其伴生的矽卡岩型和斑岩型矿床.本文以铜陵矿集区冬瓜山铜、金矿床为例,探讨了这类矿床的成矿模式.冬瓜山矿床主要由层状硫化物矿体组成,伴有矽卡岩型和斑岩型矿体.层状硫化物矿体产于晚泥盆世砂岩和晚石炭世碳酸盐岩之间,具明显的层控特征,矿体下盘发育细脉-网脉状硫化物矿化以及硅化和绢云母化,矿体中伴有热水沉积岩,矿石具典型的沉积构造.燕山期岩浆热液对层状矿体进行了叠加和改造,改变了矿石的结构构造和矿石成分.黄铜矿交代黄铁矿变斑晶呈环斑结构或脉状交代结构,交代磁黄铁矿呈交代假象结构或交代残留结构.矽卡岩型矿体中黄铜矿的δ65Cu值为0.09‰～0.83‰,集中在0.23‰～0.83‰.层状矿体中黄铜矿的δ65Cu值为0.45‰～0.78‰,与矽卡岩矿体中黄铜矿的65Cu值大致相当,这说明两类矿体中的铜具有相同的来源.铜、氢和氧同位素研究表明,冬瓜山矿床铜来自岩浆岩,叠加的成矿流体主要为岩浆流体.提出了冬瓜山矿床属喷流沉积-岩浆热液叠生成因的成矿模式:在晚石炭世,海底喷流成矿作用形成了块状硫化物矿床,矿石成分以硫、铁为主;燕山期岩浆热液一方面对块状硫化物矿床进行改造,致使其富集铜等成矿物质,另一方面与围岩相互作用形成矽卡岩型和斑岩型矿体.  相似文献   

7.
四川力马河镍矿Os同位素组成特征   总被引：1，自引：0，他引：1  
四川力马河镍矿是峨眉山大火成岩省一个有代表性的岩浆硫化物矿床,岩体主要由辉长-闪长岩及斜长辉石橄榄岩组成.Re-Os同位素分析样品包括非矿化斜长辉石橄榄岩、斑点状(浸染状)、陨铁状(网脉状)矿石及其选纯硫化物、块状硫化物.  相似文献   

8.
谢坑铜金矿床位于西秦岭造山带西段,区域内主要出露下二叠统大关山群和下三叠统隆务河群,构造和岩浆活动发育.岩石学研究表明,谢坑铜金矿区内出露侵入岩主要为辉长闪长岩和辉长岩,它们是岗察岩体的重要组成部分.在辉长闪长岩与二叠纪灰岩接触带部位发育铜金和铁矿化并形成相关工业矿体.矿石类型主要有块状、脉状和浸染状三类.磁铁矿、磁黄铁矿表现为块状,黄铜矿为脉状和浸染状;脉状和浸染状黄铜矿穿插于块状磁铁矿矿石现象十分普遍,含金碳酸盐石英脉主要沿着矿石裂隙发育.围岩蚀变呈现清晰的蚀变分带现象,自岩体向外依次表现为钾化、青磐岩化和矽卡岩化.其中矽卡岩化主要发育于辉长闪长岩与灰岩接触带部位,与成矿关系密切,磁铁矿矿化主要发育于晚期矽卡岩阶段,磁黄铁矿、黄铁矿、黄铜矿等金属硫化物以及毒砂等矿物主要形成于早期硫化物阶段,金矿化主要发育于石英硫化物阶段.LA-ICP-MS锆石U-Pb测年结果表明,辉长闪长岩和角闪安山岩分别形成于243.8±1.0Ma和242.1±1.2Ma.该成岩、成矿时代与区城构造岩浆、成矿事件相一致.这些结果表明,谢坑铜金矿床为与西秦岭中三叠世孤岩浆作用密切相关的矽卡岩型矿床.  相似文献   

9.
多彩铜铅锌矿床位于"三江"多金属成矿带北段青海省南部的治多县,是目前该地区新发现的唯一一个与古特提斯火山作用有关的大型矿床。矿体产于晚三叠世巴塘群火山岩地层中,直接赋矿围岩为英安质凝灰岩。矿区内主要发育硅化、绢云母化、黄铁矿化、绿泥石化、重晶石化、白云石化、方解石化等蚀变,矿化类型以块状及浸染状铜铅锌矿化和纹层状及星点状铜矿化为主,其次为细脉状铜铅锌矿化等。蚀变矿化在空间上具有明显分带性,以白云石-重晶石固结壳为界,下盘依次出现硅化-重晶石化-块状及细脉状矿化带、硅化-黄铁矿化-稠密浸染状矿化带、黄铁矿化-硅化-绢云母化-稀疏浸染状矿化带、硅化-弱绿泥石化带、绿泥石化带。上盘则多为成矿后中低温蚀变组合,如弱硅化-弱绢云母化-绿泥石化等。成矿演化上,矿床经历了3期主要成矿作用:火山沉积-气液矿化期、海底喷流热液矿化期及表生期。矿床地质特征、蚀变矿化分带及成矿演化等的综合分析表明,多彩铜铅锌矿床与日本黑矿及同一构造带的"三江"中段川西呷村VMS矿床极为相似,属于火山岩容矿的块状硫化物矿床。  相似文献   

10.
攀西会理县白草矿区以钒钛磁铁矿而闻名,但该钒钛磁铁矿床中还发育一定规模的富钴硫化物矿石,对该类型矿石的形成机制研究还不深入.本文选择白草矿区产出的浸染状、致密块状、网脉状和斑杂状富钴硫化物矿石中的磁黄铁矿做为研究对象,在野外地质调查的基础上,通过矿相学和电子探针等方法对磁黄铁矿的成分和晶体类型进行研究.利用磁性胶体可以鉴别磁黄铁矿晶体类型的原理,确定了研究区的磁黄铁矿具有单斜磁黄铁矿(Mpo)和六方磁黄铁矿(Hpo)两种晶体类型,厘定了细脉状、叶片状和不规则状交生体.通过研究磁黄铁矿中各主量元素特征,计算了磁黄铁矿形成温度、硫逸度和M/S值等参数.将磁黄铁矿形成划分岩浆成矿期(熔离阶段、接触交代阶段)和热液成矿期,并初步厘定了4类磁黄铁矿生成顺序:首先形成浸染状矿石磁黄铁矿与致密块状矿石磁黄铁矿,其次形成斑杂状矿石磁黄铁矿,最后形成网脉状矿石磁黄铁矿.  相似文献   

11.
Abstract: The Ashele Cu-Zn deposit is a recently discovered volcanogenic massive sulfide deposit in Xinjiang, Northwestern China. It is the largest Cu-Zn deposit in this type of deposits in China, which were formed in the early period of later Palaeozoic Era. This deposit is hosted within a suit of bimodal submarine volcanic rocks of the Ashele Formation of Lower-Middle Devonian System formed in an environment of paleocontinental margin rift setting. Lensoid orebodies occur between spilitic rocks developed at footwall and quartz-keratophyric tuff at hanging wall. Zonation of metal elements in the Ashele mine is one of typical volcanic-related exhalative Cu-Zn sulfide deposits in the world. Black ores enriched in Pb, Zn and Ag occurs on the top of the No. 1 orebody in the Ashele deposit, yellow ores enriched in Cu in the middle part, and the chalcopyritization stringer below the massive sulfide ores. Zonation of ore-structure in the No. 1 orebody is also apparent and corresponds to the zoning of elements, i. e. lamellar and/or banded sulfide-sulfate ores on the top, massive sulfide ores in the middle, and stockwork veinlets associated with altered breccia pipe on the bottom. Four epochs of mineralization in the Ashele deposit has been recognized. The first period of syngenetic-exhalative deposition of sulfides is the main epoch of mineralization, and the ores deposited subsequently subjected to thermo-metamorphism at the second epoch, superimposed by hydrothermal mineralization at the third epoch, and weathered or oxidized at the fourth epoch.
More than 100 categories of minerals have been recognized in the Ashele mine, but only pyrite, chalcopyrite, sphalerite, tetrahedrite, galena, barite, quartz, chlorite, sericite, and calcite are dominant, making up various types of ores, and alteration pipes or horizons. Studies of ore petrology suggest that the massive ores were volcanogenic and deposited by exhalative process.  相似文献   

12.
通过野外地质、岩相学、拉曼光谱和电子探针分析，对祁雨沟2号和4号含金角砾岩筒中冰长石-方解石蚀变矿物组合特征进行了描述。含金角砾岩筒成矿作用分为两期：面状矿化和脉状矿化。面状矿化的蚀变主要有阳起石化、绿色黑云母化、绿泥石化、冰长石化、硅化、绿帘石化、黄铁矿化、碳酸盐化和少量的绢云母化。脉状矿化蚀变为硅化、绢云母化和少量的碳酸盐化。通过对角砾岩筒的蚀变与成矿作用关系研究，认为冰长石-方解石蚀变与含金角砾岩金成矿作用是同期，从而确定祁雨沟含金角砾岩筒是一个典型的低硫型浅成低温热液型金矿床。  相似文献   

13.
安徽铜陵冬瓜山铜、金矿床两阶段成矿模式   总被引：21，自引：0，他引：21  
冬瓜山铜金矿床包括层状硫化物矿体、矽卡岩型和斑岩型矿体。层状硫化物矿体具层状形态和层控特征，矿石具块状、层纹状和揉皱状构造。燕山期岩浆岩及其岩浆流体对层状矿体进行了叠加和改造，改变了其结构构造、矿物组合和矿石成分，并在其上叠加蚀变和矿化。层状矿体中的铜是由含铜流体交代块状硫化物矿石形成的。冬瓜山铜金矿床经历了两次成矿作用：第一成矿阶段．在石炭纪中期，海底喷流作用形成了块状硫化物矿床，矿石成分以硫、铁矿为主；第二成矿阶段。燕山期岩浆侵人，一方面岩浆热液与围岩相互作用发生矽卡岩化、硅化、钾长石化、石英绢云母化和青磐岩化，形成矽卡岩型和斑岩型矿体，另一方面岩浆流体对块状硫化物矿体进行叠加改造，致使块状硫化物矿体富集铜等成矿物质。  相似文献   

14.
Abstract: The Bulawan deposit is located in the porphyry copper belt of southwest Negros island, Philippines. Propylitic, K–feldspar, sericitic, and carbonate alteration types can be distinguished in the deposit. Propylite alteration occurs mainly in Cretaceous-Eocene andesitic lavas and agglomerates while K–feldspar, sericite and carbonate alteration types occur mostly in the Middle Miocene dacite porphyry breccia pipes and stocks which were intruded into the andesites. K-feldspar zones occur in the inner parts of the sericitized zone. Sericite alteration overprinted the propylitized and K-feldspar alteration zones, at lower temperature than epidote and chlorite in the propylitized zone. Carbonate alteration is associated with the mineralization in the center of the breccia pipes and along faults. Mineralization consists of gold-silver telluride ores that are hosted by the carbonate– and sericite-altered dacite porphyry breccia pipes. The Bulawan ores occur mainly as disseminations, but unlike many epithermal gold deposits, lack classical epithermal colloform and crustiform quartz veins. The ore minerals are sphalerite, galena, chalcopyrite, pyrite and tetrahedite-tennantite with minor amounts of electrum, calaverite, petzite, sylvanite, hessite, tellurobismuthite, coloradoite, altaite, and rucklidgeite. Electrum and telluride minerals are associated mostly with calcite and dolomite-ankerite minerals. Fluid inclusions in quartz and calcite in clasts of propylitized andesite in the breccia pipes homogenize from about 300° to 400°C while fluid inclusions in quartz, calcite and sphalerite within the dacite porphyry breccia pipes homogenize between 300° to 310°C. The ores were formed around 300°C from hydrothermal solutions with salinity of about 6. 6 wt % NaCl equivalent. The presence of sylvanite and calaverite as intergrowths with each other, and the Ag content of calaverite are consistent with the above temperature estimate. Based on paragenesis, the Bulawan deposit formed in a pyrite-stable environment, with pH between 3. 4 and 5. 5, fO2 between 10-32 to 10-30 atm, fS2 between 10-9.8 to 10-7.8 atm, fTe2 between 10-8.9 to 10-6.5 atm, and total sulfur content about 10-2.8 molal. The dominant reduced sulfur species in the ore solutions may have been H2S(aq), and the likely aqueous tellurium species were H2Te(aq) and H2TeO3(aq). The ore minerals in the Bulawan deposit were probably formed by mixing of slightly saline and low salinity fluids.  相似文献   

15.
The Rakkejaur volcanogenic massive sulfide deposit is conformably situated in a transition zone between Proterozoic pyroclastic and overlying clastic sedimentary rocks. Ore and host rocks are isoclinally folded and slightly overturned. Two distinct types of mineralization occur: Cu-bearing stringers and disseminations, and Zn-rich stratiform banded massive sulfides. Precipitation of stratiform ore was concurrent with late volcanism and continued during the early stages of clastic sedimentation. Pyroclastic debris containing fragments of the underlying stringer-mineralized metavolcanic rocks were deposited in the lower parts of the massive sulfides. Banding of the stratiform massive ore is evidenced by alternating concentrations of pyrite and sphalerite and by interlayered sedimentary strata. Slumping and synsedimentary fragmentation of the massive sulfides took place locally. Epigenetic stringer mineralization was emplaced in two separate conduits located in the footwall metavolcanic rocks. Both mineralized vents are in contact with and beneath the same cap of massive sulfides.Zn, Pb, Ag, and Sb grades are elevated in the banded ore and tend to increase with stratigraphic and lateral distance from the zones of stringer mineralization. Gold occurs in association with arsenic or in amalgam, and each assemblage displays different distribution patterns. Most of the gold is contained in the stratiform ore where distal areas generally show higher Au/As ratios. The Au-As assemblage, however, occurs within one of the conduit zones and in close proximity to the other conduit within the massive sulfides. The ore-forming processes resulted in metasomatic alteration of the footwall rocks, mainly by introduction of Mg and Fe and depletion of Na.  相似文献   

16.
The Näsliden and Rävliden deposits in the Skellefte field consist of stratiform massive sulfide ores associated with submarine volcanic and clastic rocks. The ores are pretectonic. Consequently, the orebodies are considered to have formed syngenetically with deposition of the host rocks. Banding and interlayering with host sediments are common features. Cu : Zn and Zn : Pb ratios of the ores show stratigraphically and laterally defined trends. Cu : Pb : Zn ratios correspond with those found in other deposits of volcanogenic origin. Nonstratiform breccia Cu mineralizations occur directly under the massive stratiform ores in the footwall rocks where hydrothermal alteration is strongest. Ore formation took place intermittently resulting in clusters of ore systems occurring at slightly different stratigraphical levels within each deposit.  相似文献   

17.
粤北大宝山铜多金属矿床一直存在燕山期岩浆热液成因和海西期火山喷流成因之争,争议的焦点在于块状、似层状硫化物矿体的成因。本文在全面开展矿区地质调查和钻探查证的基础上,对块状、似层状和脉状硫化物矿石中的黄铁矿和磁黄铁矿开展EPMA和LA-ICP-MS原位分析。测试结果表明,不同产状黄铁矿的平均分子式相似,分别为FeS_(1.98)、FeS_(1.99)和FeS_(1.98),似层状和脉状硫化物中磁黄铁矿的平均化学式为Fe_(0.886)S和Fe_(0.874)S,属形成温度相对较低单斜磁黄铁矿。与花岗岩岩浆热液标型黄铁矿相比,不同产状的黄铁矿和磁黄铁矿中Co、Ni、Mn、Se和Ge等元素以类质同象形式赋存,它们含量较低但稳定,Cu、Pb、Zn、Ag、Bi和Tl及Ga主要以微细矿物子晶形式存在,其含量丰富,但变化明显。从块状、似层状到脉状硫化物矿体,黄铁矿和磁黄铁矿中Co、Zn和Se的含量及Co/Ni值降低,而Cu、Pb、Ag、Bi等元素的含量明显升高。结合矿区次英安斑岩的产状和含矿性特征表明,大宝山矿床块状、似层状和脉状硫化物矿体都是次英安斑岩深部岩浆房产出的含矿流体在不同赋矿环境中的产物。  相似文献   

18.
智利Copiapó附近海岸东部边缘有一宽5km、长20km的铁氧化物铜金矿床带,包括Candelaria矿床和位于其北东方向3km处的Punta del Cobre矿集区的中小型矿床。初步估计,该成矿带的铜矿石资源量可达7×108~8×10~8t(含铜量1%)。矿石矿物主要为黄铜矿、黄铁矿、磁铁矿、赤铁矿。矿石产状为脉状、角砾状、细脉状等。含矿围岩主要为Punta del Cobre组的火山岩及火山碎屑岩。该矿带中大部分大型矿脉位于北西—北北西向高角度脆性断层与块状火山岩和火山碎屑岩接触带交汇处。Candelairia矿区主要发育黑云母-钾长石±钙角闪石±绿帘石蚀变矿物组合。在Punta del Cobr矿集区,矿床深部的矿石围岩蚀变情况与Candelairia地区一致,但是浅部的矿石赋存于黑云母-钾长石或钠长石-绿泥石±方解石蚀变带中。  相似文献   

19.
吉林省香炉碗子金矿床矿化特征及成因机理探讨   总被引：3，自引：0，他引：3  
香炉碗子金矿床产于中生代形成的隐爆角砾岩体中，隐爆岩体又受脆韧性剪切带控制，金矿化与铁铁绢英岩化关系密切，本文论述了矿床的矿体，矿化及矿石等特征，并探讨了矿床成因和成矿机理。  相似文献   

20.
上世纪90年代中期通过成矿预测发现的水银洞金矿床,通过近10年的勘查,成为特大型层控金矿床。矿体呈层状、似层状产出于灰家堡背斜轴部附近300m范围内二叠统龙潭组的大孔隙度生物碎屑灰岩中,形态与背斜形态一致。矿体严格受控于碳酸盐岩,顶板和底板皆为粘土岩或粉砂质粘土岩,界线清楚。矿化表现为“硅化、白云石化、黄铁矿化”组合。硅化与白云石化是成矿的先决条件,碳酸盐岩最终能否成矿及品位的高低,取决于是否具有黄铁矿化热液蚀变及其强度。矿床具矿体多、厚度薄、品位富的特点。单矿体即达中型矿床规模。具中—低温超高压热液成矿的特点。金赋存于沿自形黄铁矿内核生长成的含砷黄铁矿环带中。  相似文献   

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