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1.
夏塞银多金属矿床中硫化物和硫盐系列矿物特征及其意义   总被引:4,自引:1,他引:3  
黄典豪  胡世华 《矿床地质》2000,19(4):363-375
夏塞矿主档是大型的热液脉型银多金属矿床,通过对大量矿石光(薄)片观察和电子探针分析表明,除主要(方铅矿、富铁闪锌矿)和次要(黄铁矿、毒砂、磁黄铁矿、黄铜矿等)硫化物外,硫盐毓硫物十分发育,主要有Cu-Sb-Ag硫盐(黝铜矿、含银黝铜矿和银黝铜矿)、Sb-Ag硫盐(深红银矿、辉锑银矿)、Pb-Sb硫盐(脆硫锑铅矿、硫锑铅矿)和Bi-Pb硫盐(斜方辉饿铅矿)。此外,尚有少(微)量黄锡矿、锡石、自然饿和银金矿等。银的硫盐硫物和硫化物(辉银矿)乃是获得银的主要工业矿物,这些硫盐毓矿物常与硫化物伴生,多沿方铅矿、富铁闪锌矿、黄铁矿等的解理、裂隙或粒间产出,这些研究结果不仅有助于了解矿化作用过程,而且为矿床评价,组分综合利用和选冶提供重要依据。  相似文献   

2.
周兵  顾连兴 《地质论评》1999,45(1):15-18
福建尤溪梅仙块状硫化物矿床中的闪锌矿经50%HNO3浸蚀后发现,微米级的黄铜矿交生体呈乳滴状,棒条状,蠕虫状等沿闪锌矿解理面,双晶面和颗粒边界,裂隙等处分布,并且黄铜矿交生体所占体积均在5%以上,因上闪锌矿中有限的Cu的溶解度使出溶无法解释黄鲷矿交生体的成因,交生体的结构特征以其与黄铜矿脉的关系暗示其可能是交代成因。而对横切黄铜矿乳滴的电子探针分析中铁含量特征的研究,证实梅仙矿区闪锌矿中的黄铜矿交  相似文献   

3.
MVT型铅锌矿床中矿物组成一般较简单,铜矿物非常少见。云南富乐铅锌矿床是川滇黔MVT型铅锌成矿域中代表性 大型铅锌矿床,其赋矿层位为该区最新地层-中二叠统阳新组白云岩,矿体距上覆峨眉山玄武岩不到160 m。通过矿相、 扫描电镜及能谱等分析测试,本研究在该矿床中发现了大量铜矿物,主要包括以下四类,即黄铜矿、锌砷黝铜矿、黝铜矿 和孔雀石,这些铜的独立矿物常交代闪锌矿和黄铁矿等矿物,形状多为环带状、脉状及不规则状等,部分黄铜矿呈乳滴状 分布于闪锌矿颗粒内部或呈他形交代闪锌矿,可能与闪锌矿同时形成,锌砷黝铜矿和黝铜矿呈他形细脉状穿插于闪锌矿或 分布于闪锌矿边缘及孔洞中,暗示这些铜矿物形成略晚于铅锌成矿。上述铜矿物常见于中低温热液铅锌矿床,其中锌砷黝 铜矿是硫盐矿物中较罕见的矿物,黝铜矿和锌砷黝铜矿的出现指示相对氧化的成矿环境,而孔雀石是在铜矿物的氧化过程 中形成的次生矿物。研究表明,本矿床矿石矿物的生成顺序为:黄铁矿→闪锌矿(乳滴状黄铜矿) →方铅矿→黄铜矿→锌 砷黝铜矿→黝铜矿→孔雀石,结合矿床产出的地质地球化学特征,云南富乐铅锌矿床中铜可能有两个来源:早期的乳滴状 黄铜矿与铅锌矿同期且均来自基底地层--昆阳群;后生铜矿物(黄铜矿、黝铜矿和锌砷黝铜) 主要来源于上覆峨眉山玄 武岩,这与铅锌主要来源于昆阳群等基底地层有所差异,研究成果为认识川滇黔地区铅锌成矿作用与峨眉山玄武岩关系提 供了新的地球化学依据。  相似文献   

4.
顾连兴  周兵  张文兰 《矿床地质》1998,17(Z4):675-678
矿石结构和电子探针成分研究表明,福建梅仙铅锌矿区闪锌矿中的黄铜矿产生体,除了形成高度分散的乳滴外,还呈棒条状、蠕虫状和叶片状沿闪锌矿的解理和双晶界面分布。这种交生体除了部分可能是出溶产物外,主要应是黄铜矿交代闪锌矿的产物。交代过程中由溶液带入的不仅有铜,而且还有铁。当交代热液前锋在硫化物矿床中不断向前推进时,锌和铅不断深解而铜不断沉淀,于是先存的硫化物矿体便不断受到带状提炼。因带状提炼而发生再活化转移的锌和铅,在环境物理化学条件发生改变时便重新沉淀,从而在梅仙矿区上方形成了贫铜的锌-铅矿体。  相似文献   

5.
朱锡涛 《地质论评》1988,34(5):414-421
本矿床银的第一个成矿阶段产物实质上是锌、铜、铅硫化物阶段的晚期相。从方铅矿中以固溶体分解形式先析出针硫铋银矿、硫银铋矿等,最后,沿方铅矿解理、晶粒间隙和闪锌矿边界处析出较多的含银黝铜矿。第二个阶段银沿构造微裂隙充填交代方铅矿-闪锌矿-黄铁矿矿体,相继生成深红银矿和硫锑铜银矿,前者常选择交代含银黝铜矿,后者常选择交代深红银矿和闪锌矿内的黄铜矿不混溶包体。第一阶段银矿物组合成顺向沉淀垂直分带,下部以银铋硫盐为主,向上银锑铜硫盐相对富集。由于第二阶段叠加的银锑硫盐交代作用由矿体中部往上逐步加强,因而形成交代重叠垂直分带。据此讨论了深部银矿化演变的趋势和远景。  相似文献   

6.
英城子金矿床位于兴蒙造山带东缘,矿床产于近东西向韧性脆性剪切带(靡棱岩带)内,矿体主要呈透镜状、似层状和脉状产出.矿石矿物主要为黄铁矿、闪锌矿和黄铜矿,主要结构为交代结构、乳滴状结构、半自形-他形结构,主要构造为浸染状构造、脉状构造、条带状构造.成矿作用先后经历了4个阶段:石英-毒砂-黄铁矿阶段、石英-黄铁矿阶段、石英-多金属硫化物阶段和石英-方解石阶段.成矿流体总体属于中温、低盐度、低密度的CO2-CH4-H2O体系.英城子金矿床与国内外典型的造山型金矿相比具有诸多相似之处,其成因类型属于造山型金矿.  相似文献   

7.
对辽宁青城子铅锌-银-金矿床的主要矿石矿物方铅矿、闪锌矿和黄铁矿进行了显微鉴定、电子探针和ICP-MS分析,获得它们的固结顺序为:黄铁矿早于闪锌矿,二者早于方铅矿(闪锌矿交代黄铁矿,方铅矿交代前两者)。从硫化物成分空间分布可以判断成矿流体以甸南-榛子沟为中心分别向二道-喜鹊沟和大地-白云迁移。根据方铅矿固结温度(327℃)参考石英流体包裹体均一温度(322℃),限定以方铅矿为主的矿床其硫化物形成温度约为322~327℃;利用Cd在方铅矿-闪锌矿分配系数温度计获得铅锌矿成矿温度在344~464℃之间,结合闪锌矿出溶黄铜矿温度(高于350℃),参考石英流体包裹体均一温度(300~360℃),并参考黄铁矿发生脆性变形温度(400℃),获得以闪锌矿为主的矿床硫化物形成温度约为360~400℃,银铅锌矿床的成矿温度被限定在390~400℃;由于自然金主要赋存在黄铁矿微裂隙中,利用黄铁矿发生脆性变形温度并结合石英流体包裹体温度(230~370℃)约束金成矿温度约为370~400℃。成矿温度较高可能归因于样品采集位置较深所致;最后利用矿石矿物、侵入岩、围岩微量元素对比分析判断成矿流体与中生代(特别是印支期)侵入岩具有亲缘性,根据印支期岩浆混合特征认为岩浆混合作用可能对本地区成矿作用具有重要贡献。  相似文献   

8.
三道明水矿床位于北山成矿带的西部,是近年来新发现的一个中型Cu-Zn矿。为了解该矿床成因类型及主要控矿因素,本文在前期勘探工作的基础之上,对其矿床地质特征,特别是蚀变矿化特征开展了野外及室内研究。根据热液蚀变、矿物组合及脉体间穿插关系的不同,可将三道明水矿床的蚀变和矿化划分为早、中、晚3期。其中,早期矿化以黄铁矿±黄铜矿±闪锌矿、黄铁矿-闪锌矿±黄铜矿组合,以及零星浸染状黄铁矿-黄铜矿-闪锌矿组合为特征,相关的热液蚀变为绿泥石±绢云母,显示出块状硫化物矿床的蚀变矿化特征;中期矿化为该矿床的主要成矿阶段,以浸染状黄铜矿-闪锌矿-黄铁矿组合为特征,相关蚀变为绢英岩化,含Cu、Zn矿物(黄铜矿、闪锌矿)形成于韧性变形过程中;晚期矿化主要以石英±黄铜矿±辉钼矿脉±黄铁矿脉、方解石脉发育为特征,蚀变不明显。基于上述蚀变矿化特征的观察,并通过与区域成矿作用的综合对比,认为三道明水矿床早期可能为块状硫化物型(VMS)矿化,中期经历了韧性剪切变形驱动下的热液改造,在主剪切带富集形成了工业矿体,晚期叠加了岩浆热液有关的Cu-Mo矿化。  相似文献   

9.
新疆哈密卡拉塔格块状硫化物矿床金银赋存状态研究   总被引:3,自引:0,他引:3  
新疆哈密红海黄土坡VMS矿床位于东天山卡拉塔格隆起带,是卡拉塔格矿集区内新发现的块状硫化物矿床。矿体产于卡拉塔格隆起带核部火山沉积岩建造中,具有典型的VMS型矿床“上层下脉”二元结构特征。该矿床中含金硫化物矿石主要有块状黄铁矿黄铜矿、块状黄铁矿黄铜矿闪锌矿、块状黄铁矿闪锌矿黄铜矿和块状闪锌矿。文中在对各类含金硫化物矿石进行详细的矿相学研究基础上,结合扫描电子显微镜与能谱仪联用技术(SEM/EDS),对硫化物样品中金、银的赋存状态进行研究。结果表明,4种块状硫化物中的主要矿物形成于多个期次,主要包括VMS成矿期(黄铁矿阶段、闪锌矿黄铜矿黝铜矿方铅矿阶段、石英重晶石阶段)、热液叠加期(石英黄铁矿黄铜矿闪锌矿方铅矿阶段)和表生期(铜蓝纤铁矿阶段)。矿区首次发现4颗金银金属互化物(银金矿、碲银矿),其较大的化学成分差异指示了热液环境由中酸性中性转变为更有利于Au、Ag迁移沉淀的偏碱性。后期的偏碱性热液对VMS成矿期形成矿物产生了交代作用,使得Au、Ag活化再富集。由于后期热液叠加改造,红海VMS型矿床中Au、Ag不仅赋存于VMS成矿期后期中低温闪锌矿黄铜矿阶段,也赋存于VMS成矿期早期中高温黄铁矿阶段,并贯穿整个热液叠加期。各含金矿物组合中除4颗金银金属互化物外Au多呈显微不可见状态,推测Au、Ag主要以原子或离子形式赋存于矿物晶格中或矿物空位处。  相似文献   

10.
硫化物矿物对银的表面吸附作用及其成矿意义   总被引:4,自引:0,他引:4  
吴大清  彭金莲 《地球化学》1996,25(4):372-378
通过硫化物矿物对银离子的吸附实验研究表明,在50℃时,硫化物矿物对溶液中银离子的等温饱和吸附量大小顺序是:方铅矿>黄铜矿>辉锑矿>闪锌矿;当温度超过70℃时,这个顺序变为:辉锑矿>方铅矿>黄铜矿>闪锌矿。这与天然多金属矿床中硫化物矿物银的含量顺序是一致的。实验证明,硫化物具有把溶液中的银富集到固体(矿物中)达106量级以上的能力。这些结果极好地解释了多金属矿床中银在普通硫化物中含量大小的顺序及锑和银在矿床和矿物上密切共生的关系。  相似文献   

11.
The Laloki and Federal Flag deposits are two of the many (over 45) polymetallic massive sulfide deposits that occur in the Astrolabe Mineral Field, Papua New Guinea. New data of the mineralogical compositions, mineral textures, and fluid inclusion studies on sphalerite from Laloki and Federal Flag deposits were investigated to clarify physiochemical conditions of the mineralization at both deposits. The two deposits are located about 2 km apart and they are stratigraphically hosted by siliceous to carbonaceous claystone and rare gray chert of Paleocene–Eocene age. Massive sulfide ore and host rock samples were collected from each deposit for mineralogical, geochemical, and fluid inclusion studies. Mineralization at the Laloki deposit consists of early‐stage massive sulfide mineralization (sphalerite‐barite, chalcopyrite, and pyrite–marcasite) and late‐stage brecciation and remobilization of early‐stage massive sulfides that was accompanied by late‐stage sphalerite mineralization. Occurrence of native gold blebs in early‐stage massive pyrite–marcasite‐chalcopyrite ore with the association of pyrrhotite‐hematite and abundant planktonic foraminifera remnants was due to reduction of hydrothermal fluids by the reaction with organic‐rich sediments and seawater mixing. Precipitation of fine‐grained gold blebs in late‐stage Fe‐rich sphalerite resulted from low temperature and higher salinity ore fluids in sulfur reducing conditions. In contrast, the massive sulfide ores from the Federal Flag deposit contain Fe‐rich sphalerite and subordinate sulfarsenides. Native gold blebs occur as inclusions in Fe‐rich sphalerite, along sphalerite grain boundaries, and in the siliceous‐hematitic matrix. Such occurrences of native gold suggest that gold was initially precipitated from high‐temperature, moderate to highly reduced, low‐sulfur ore fluids. Concentrations of Au and Ag from both Laloki and Federal Flag deposits were within the range (<10 ppm Au and <100 ppm Ag) of massive sulfides at a mid‐ocean ridge setting rather than typical arc‐type massive sulfides. The complex relationship between FeS contents in sphalerite and gold grades of both deposits is probably due to the initial deposition of gold on the seafloor that may have been controlled by factors such as Au complexes, pH, and fO2 in combination with temperature and sulfur fugacity.  相似文献   

12.
我国一些铜镍硫化物矿床主要金属矿物的特征   总被引:7,自引:0,他引:7  
镍、铜共生的铜镍硫化物矿床是镍矿也是铜矿的重要矿床类型。磁黄铁矿,镍黄铁矿、黄铜矿是这类矿床的主要金属矿物。它们的某些矿物学特征,特别是微量元素Co/Ni比值,与其他铜矿类型明显不同,这三种矿物组成不同于任何其他铜矿类型的典型矿物共生组合, 形成特殊的海绵损铁状、球滴状构造。  相似文献   

13.
Assemblages and chemical compositions of ore minerals from the Yamato mine, Yamaguchi Prefecture, Japan, were investigated in detail to clarify its characteristics as a skarn deposit. Special attention was paid to silver‐, bismuth‐, cobalt‐, and tin‐bearing sulfide minerals and native gold at the mine, which are described here for the first time. Samples of arsenopyrite‐dominant massive ore, and garnet‐rich, clinopyroxene‐garnet‐rich, and wollastonite‐bearing skarn ores were collected from the mine dump. Arsenopyrite is the most abundant ore mineral (>80 vol.%) in the massive ore, in association with both As‐poor/free and As‐bearing pyrite. The major ore minerals in the skarn specimens are pyrite, pyrrhotite, arsenopyrite, chalcopyrite, galena, and sphalerite, along with minor argentite, Ag‐Pb‐Bi sulfate, matildite, bismuthinite, native bismuth, molybdenite, scheelite, stannite, stannoidite, cassiterite, cobaltite, gersdorffite, and Co‐rich violarite. In addition, native gold is observed in the interstices of gangue minerals. Based on the mineral assemblages and textures of the specimens examined, the major ore minerals formed in the early stage of mineralization, and the Bi‐, Ag‐, Co‐, Ni‐, As‐ and Sn‐mineralization occurred in the middle stage. Native gold was deposited in the late stage. The estimated formation temperature of the middle mineralization stage was 312±5 °C, according to iron and zinc partitioning between stannite and coexisting sphalerite. The mineralogical properties and mineralization process of the Yamato mine are consistent with those of common skarn‐ and vein‐type ore deposits associated with ilmenite‐series granitoids in the San‐yo and San‐in districts.  相似文献   

14.
Abstract: Polymetallic mineralization at the Nakakoshi deposits, Kamikawa town, central Hokkaido, occur as fracture-filling veins in Cretaceous slate of the Hidaka Supergroup. Ten veins have been recognized in NE-SW and E-W directions. Sericite in altered slate which is the host of the deposits, was dated at 31. 1 Ma, Oligocene in age.
No. 9 vein consists of massive chalcopyrite ore with various kinds of minerals such as pyrite, pyrrhotite, arsenopyrite, sphalerite, tetrahedrite, Ag-minerals and Cu–Zn–Fe–In–Sn–S minerals, quartz and sericite. Chalcopyrite and pyrite contain sphalerite star and sphalerite with chalcopyrite emulsions. Maximum indium contents of sphalerite and the Cu–Zn–Fe–In–Sn–S minerals are 1. 8 and 16. 3 wt%, respectively. The sulfur isotopic ratios, δ34S of ore minerals, range from –12. 9 to –9. 6%. Formation temperatures of the sulfide minerals are estimated as 300–500°C, based on the paragenesis and chemical compositions of the minerals.  相似文献   

15.
In the Ospin–Kitoi ultramafic massif of the Eastern Sayan, accessory and ore Cr-spinel are mainly represented by alumochromite and chromite. Copper–nickel mineralization hosted in serpentinized ultramafic rocks occurs as separate grains of pentlandite and pyrrhotite, as well as assemblages of (i) hexagonal pyrrhotite + pentlandite + chalcopyrite and (ii) monoclinal pyrrhotite + pentlandite + chalcopyrite. Copper mineralization in rodingite is presented by bornite, chalcopyrite, and covellite. Talc–breunnerite–quartz and muscovite–breunnerite–quartz listvenite contains abundant sulfide and sulfoarsenide mineralization: pyrite, gersdorffite, sphalerite, Ag–Bi and Bi-galena, millerite, and kuestelite. Noble metal mineralization is represented by Ru–Ir–Os alloy, sulfides, and sulfoarsenides of these metals, Au–Cu–Ag alloys in chromitite, laurite intergrowth, an unnamed mineral with a composition of Cu3Pt, orcelite in carbonized serpentinite, and sperrylite and electrum in serpentinite. Sulfide mineralization formed at the late magmatic stage of the origination of intrusion and due to fluid–metamorphic and retrograde metasomatism of primary rocks.  相似文献   

16.
We conducted experiments to simulate sulfide remobilisation from sulfide ore. The starting material was from the Hongtoushan massive sulfide deposit, NE China, and is composed of pyrite, pyrrhotite, chalcopyrite, sphalerite, quartz, and silicate minerals. The ore was immersed in a solution of 20 wt.% NaCl for 260 h, and then was mounted in a Changjiang 500 triaxial rock stress machine. After the experiments were performed for 13 h at temperatures of 362, 464, 556 and 682°C, with corresponding confining and axial pressures, the samples were cooled at room temperatures. Our results from all the runs indicate that sulfides can be remobilised both mechanically and chemically, and that remobilisation is enhanced at higher temperatures. Mechanical remobilisation can only take place over limited distances and results in minor differentiation between various sulfide minerals. Distant external remobilisation to form new orebodies is most likely caused by chemical remobilisation. In contrast to plastically deformed areas, space resulting from cataclastic deformation could provide conduits for fluid transport and space for metal precipitation. Remobilised iron sulfides will precipitate as pyrrhotite at high temperatures, but as pyrite when temperature decreases. Furthermore, chalcopyrite is more easily remobilised than sphalerite under the conditions of the present experiments. Remobilisation accompanying deformation and metamorphism may add epigenetic features to syngenetic deposits.  相似文献   

17.
朝山金矿的主要矿石类型为含金硫铁矿石,矿石中富含铋矿物,且作为主要载金矿物,是该矿床的标型特征和重要找矿标志.矿石多呈结晶粒状结构、各种充填-交代结构,块状、浸染状、细脉状构造.金矿物以形态复杂的微粒、细粒自然金、银金矿、金银矿为主,赋存形式有晶隙金、包体金、连生金、裂隙金,载金矿物为石英、自然铋、辉铋矿、磁黄铁矿、黄铁矿、黄铜矿、毒砂等.综合分析认为:该矿床是典型的夕卡岩型独立金矿,成矿流体的不混溶是金富集成矿的主因.  相似文献   

18.
内蒙古维拉斯托-拜仁达坝矿床矿石特征及成矿机理   总被引:2,自引:0,他引:2       下载免费PDF全文
维拉斯托-拜仁达坝锌铜多金属矿床为近几年大兴安岭中南段西坡发现的较大的2个银多金属矿床,主要对2个矿床矿石矿物组合分析和对比,对主要的矿石矿物组合进行扫描电子显微镜-能谱分析和电子探针分析显示:从早期到晚期,矿物组合从高温钨酸盐和氧化物-复硫化物-硫化物-低温含锑硫盐矿物(锑化物);银的赋存状态主要为可见银矿物,其次为晶格银(类质同象)和次显微包裹银,其中生成顺序依次为含银黝铜矿+银锑黝铜矿+黝锑银矿-辉锑铅银矿+柱硫锑铅银矿+深红银矿+锑银矿.根据不同成矿阶段的矿物组合和流体包裹体特征得出:成矿早期在氧化偏酸性环境下,W、Sn等以钨酸、钨酸盐等形式迁移,Zn2+、Pb2+、Cu+等金属离子以氯络合物形式迁移;随着黑钨矿气化沉淀及成矿流体物理化学条件的变化,成矿中-晚期成矿环境变为弱碱性还原条件,成矿流体中金属离子以硫氢络合物迁移为主,伴着温度降低和围岩的水-岩作用,硫氢络合物分解,导致磁黄铁矿等硫化物、硫锑银矿物、硫锑铅矿等依次沉淀.   相似文献   

19.
Abstract. A detail investigation of ore and gangue minerals was performed on the Doyashiki Kuroko deposits, Hokuroku basin, Japan for the first time. Main ore minerals are sphalerite, galena, pyrite, chalcopyrite, tetrahedrite-tennantite and digen-ite. Small amounts of enargite, wittichenite, electrum, covellite, bornite, marcasite and hematite are also observed. Quartz, barite and gypsum are common gangue minerals. Homogenization temperatures and salinities of fluid inclusions in quartz, sphalerite and barite range from 190 to 240C and 3.0 to 5.5 wt% NaCl equivalent, respectively. The FeS contents of sphalerite and Ag contents of electrum were 0.12 to 0.18 mol %, 39.0 to 39.6 atom %, respectively. The chemical composition of digenite as a primary mineral shows high sulfur contents.
These data indicate that ore fluid responsible for digenite and associated ore minerals was characterized by a range of high sulfur fugacity with a moderate formation temperature. This is concordant with the mineral assemblage of bornite-pyrite and chalcopyrite, which shows high sulfur fugacity conditions. It seems that the mineralization closely associated with acidic volcanism has occurred around 13 Ma of Middle Miocene on the seafloor at the depth of about 1500 m.  相似文献   

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