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1.
《矿物岩石地球化学通报》2016,(1)
香山铜镍矿床是东天山觉罗塔格成矿带北缘中型铜镍矿床,资源前景颇佳。对香山铜镍矿床中富铜矿石、富镍矿石和浸染状矿石内磁黄铁矿、镍黄铁矿和黄铜矿进行了电子探针分析,以期研究铂元素的富集机制。结果表明,磁黄铁矿和镍黄铁矿早于黄铜矿形成,更富集Co和Se元素,黄铜矿则富集Sb、Bi和Zn等低温元素。Pt元素主要通过岩浆作用富集,但磁黄铁矿和镍黄铁矿中丰度更高,硫化物熔体分异不均衡是导致这种差异性的原因之一。富铜矿石全岩Pt元素含量最高,其原因是Pt元素热液活动性强,且富铜矿石经受了热液作用改造。 相似文献
2.
坡七侵入体位于新疆塔里木板块东北缘,是坡北岩体第三期次岩浆作用的产物。该侵入体主要的岩石类型有二辉橄榄岩、橄榄辉石岩、方辉辉石岩、橄长岩、苏长岩、辉长岩以及辉长闪长岩。橄榄岩相和苏长岩相中赋存铜镍硫化物矿(化)体,矿石构造类型有浸染状、稠密浸染状和块状。金属硫化物主要为磁黄铁矿、镍黄铁矿、黄铜矿和黄铁矿,金属矿物生成顺序为:铬尖晶石-(第1世代镍黄铁矿Pn~1、第1世代黄铜矿Ccp~1)-NC型磁黄铁矿-(第2世代镍黄铁矿Pn~2、4C型磁黄铁矿、第2世代黄铜矿Ccp~2、第1世代黄铁矿Py~1)-第3世代镍黄铁矿Pn~3-(第2世代黄铁矿Py~2、第3世代黄铜矿Ccp~3)。其中,磁黄铁矿、镍黄铁矿矿物学特征表明,岩(矿)体侵位过程中,高温阶段温度下降缓慢,低温阶段温度下降较快,晚期有热液作用叠加。成矿期可以划分为岩浆成矿期(岩浆熔离阶段和单硫化物固溶体分异阶段)及热液成矿期。依据矿石结构构造、金属矿物矿物学特征综合分析,坡七侵入体深部硫化物熔离充分,成矿潜力大。 相似文献
3.
金川铜镍硫化物矿床是我国最主要的铂族元素(PGE)资源产地,其矿石受热液蚀变作用影响明显,并产出多种铂族矿物(PGM)。岩浆演化和热液蚀变过程中PGE的迁移富集机制和PGM的成因,一直是研究PGE地球化学行为非常关注的问题。本文对金川铜镍硫化物矿床中PGM的研究发现,其主要类型包括含PGE的硫砷化物(硫砷铱矿)和砷化物(砷铂矿),Pd的铋化物、碲化物和硒化物,以及少量其他铂族矿物。其中,硫砷铱矿可包裹于各种贱金属硫化物(镍黄铁矿、磁黄铁矿和黄铜矿)中,表明硫砷铱矿可能结晶于早期的含As硫化物熔体,随后被包裹于硫化物熔体冷凝分异产生的单硫化物固溶体(MSS)和中间硫化物固溶体(ISS)中。硫化物熔体中的As可能主要通过地壳混染作用加入幔源岩浆。大量铋钯矿(PdBi)呈微细乳滴状包裹于黄铜矿中,为晚期ISS冷凝形成黄铜矿过程中出溶的产物。少量铋钯矿(PdBi_2)呈不规则状充填于矿物裂隙,与次生磁铁矿脉紧密共生,并随矿石的蚀变程度增加,铋钯矿的化学成分由PdBi逐渐向PdBi_2转变,表明这部分铋钯矿为后期热液蚀变产物。铋碲钯矿和钯的硒化物则主要产出于镍黄铁矿裂隙且与次生磁铁矿紧密共生,指示明显的热液成因。钯的硒化物的出现表明,岩浆期后酸性、高盐度、高氧逸度的富Cl~-流体对金川铜镍硫化物矿床中Pd的迁移和富集起到了关键控制作用。 相似文献
4.
5.
东天山主要铜镍矿床中磁黄铁矿的矿物标型特征及其成矿意义 总被引：3，自引：4，他引：3
东天山是中国最重要的岩浆铜镍硫化物矿带之一,产有黄山东、黄山、香山、葫芦等大中型铜镍矿床。图拉尔根、白石泉两处镍铜矿床为近年来在新疆地区铜镍找矿中的重大发现,两者均属于与镁铁质-超镁铁质杂岩有关的岩浆熔离-贯入型矿床。矿物共生组合以磁黄铁矿 镍黄铁矿 黄铜矿为特征,磁黄铁矿系矿石中最主要组成部分。文章以X射线衍射、扫描电镜、电子探针分析并辅以常规显微镜,查明这些矿床中磁黄铁矿均系Co、Ni的最主要载体矿物,Co、Ni元素主要以游离状态的硫化物(或硫砷化物)形式存在,如镍辉砷钴矿、钴辉砷镍矿、镍黄铁矿及紫硫镍矿等矿物。它们多以微细包裹体或出溶体形式随机地分布于磁黄铁矿内部,而少量的Co、Ni元素则以类质同像方式存在于磁黄铁矿晶格之中。图拉尔根、白石泉、葫芦三矿床中磁黄铁矿在多型结构以及微量元素地球化学方面均表现出一定的差异,系由两矿床容矿岩石基性程度及成矿温度之差异引起。 相似文献
6.
《矿物岩石地球化学通报》2017,(6)
为探讨新疆坡北岩体坡七侵入体中铜镍硫化物矿(化)体的成因,采用显微镜观察、磁性胶体浸润和电子探针分析等方法,对主要的金属矿物磁黄铁矿、镍黄铁矿开展了成因矿物学研究。结果表明,浸染状、稠密浸染状矿石中,磁黄铁矿为六方(NC型)磁黄铁矿,或六方磁黄铁矿与散点状单斜(4C型)磁黄铁矿构成的不规则状交生体。六方磁黄铁矿是高温结晶后缓慢降温的产物,而不规则状交生体是流体交代六方磁黄铁矿的结果。块状矿石中的磁黄铁矿是六方与单斜变体构成叶片状/箱状交生体,其成因与快速降温和热事件干扰有关。镍黄铁矿富集Co,在各类矿石中均可分为3个世代(Pn1,Pn2,Pn3),在结晶过程中硫逸度随着温度的降低而减小。等轴晶系辉砷钴矿、自形镍黄铁矿及高温黄铜矿的晶出暗示金属硫化物结晶温度普遍偏高。 相似文献
7.
西秦岭谢坑矽卡岩型铜金矿床地质特征与矿区岩浆岩年代学研究 总被引：5，自引：5，他引：0
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
8.
新疆喀拉通克铜镍硫化物矿床铂族矿物特征、成因及其形成过程 总被引：1，自引：0，他引：1
通过矿相学和电子探针研究发现,新疆喀拉通克矿床铂族矿物以Pt、Pd、Ni的碲化物、铋化物固溶体系列矿物为主,矿物分布不均匀,主要分布在块状矿石的磁黄铁矿、镍黄铁矿、黄铜矿等硫化物中,粒径多为3～5μm。矿物组合和相图分析显示,多数铂族矿物为岩浆熔离成因,个别矿物颗粒可能为热液叠加成矿的产物。岩浆中S不饱和时,PGE可能形成铂铑合金,局部氧逸度升高导致铬铁矿、磁铁矿等氧化物结晶,合金被早期结晶的硅酸盐矿物和氧化物包裹。硫化物熔离大量的PGE进入硫化物熔体,伴随硫化物熔体的分异,部分铂族矿物被包裹在单硫化物固溶体中;高温条件下结晶的Pd(+Pt,Ni)-Bi-Te固溶体系列矿物不稳定,随着温度的降低,Pd(+Pt,Ni)-Bi-Te固溶体出溶形成上述铂族矿物组合,MSS裂解铂族矿物被排出,岩浆热液可能形成少量具热液成因特征的铂族矿物。 相似文献
9.
中亚造山带南缘东天山地区是我国战略资源Ni的重要产区,图拉尔根矿床是该地区众多铜镍矿床中以岩体高矿化比例为特色的矿床。图拉尔根杂岩体由晚石炭世基性岩体(辉长岩、角闪辉长岩)和早二叠世超基性岩体(二辉橄榄岩、角闪橄榄岩)组成,矿体呈透镜状、“悬浮”状产出于超镁铁岩体的中部和中上部,矿化类型为块状/半块状、海绵陨铁状、稠密/稀疏浸染状、星点状、斑杂状以及少量珠滴状矿化。不同类型矿石∑PGE变化较大(10.8×10-9～208×10-9),除块状矿石样品外,其他类型矿石(S<15%)S与PGE、IPGE与PGE元素之间均显示良好正相关,表明PGE含量变化主要受控于R因子(100～5000)变化;块状矿石的上述元素间呈现离散现象,亦反映单硫化物固溶体分异的影响。母岩浆中Pt和Pd的显著亏损以及矿石中Cu和Pd的强烈解耦,表明图拉尔根母岩浆经历了深部硫化物的熔离。Pd/Ir比值揭示的高镁玄武质岩浆性质和含水地幔源区可能的低程度部分熔融,表明源区硫化物残留也可能造成PGE的亏损。图拉尔根矿床的187Os/188 相似文献
10.
哈密图拉尔根铜镍矿Ⅰ号岩体矿床特征及成矿研究 总被引：1，自引：0，他引：1
岩浆型Cu-Ni-PGE硫化物矿床是指与镁铁质-超镁铁质岩浆成矿作用有关的、以硫化物为主的矿床.图拉尔根铜镍矿属于岩浆熔离贯入型矿床,辅有就地熔离、热液叠加成矿多重作用形成的矿床.Ⅰ号岩体以全岩矿化为特征,可分为角闪橄辉岩、角闪辉石岩、橄榄辉石岩和辉长岩4个岩相,块状矿化和海绵陨铁特富矿体主要产在角闪橄辉岩相中.矿石中磁黄铁矿-镍黄铁矿-黄铜矿共生为其主要特征,此外,金属矿物还有磁铁矿及少量钛铁矿.脉石矿物主要有普通角闪石、蛇纹石、透辉石、氟钠透闪石-钙镁闪石及绢云母、白云母、方解石、磷灰石.通过室内大量工作,对本矿床矿石矿物、结构特征及成矿过程进行了总结,研究认为,原始岩浆在深部岩浆房中发生了熔离作用和重力分异,形成矿体和不同岩相.图拉尔根铜镍矿体分异侵位之后产于比重较大的角闪橄辉岩相带内,整个铜镍硫化物矿床的形成存在一个由岩浆到热液的演化系列和不同阶段的富集成矿. 相似文献
11.
Sarah-Jane Barnes R. A. Cox M. L. Zientek 《Contributions to Mineralogy and Petrology》2006,152(2):187-200
Concentrations of Ag, Au, Cd, Co, Re, Zn and Platinum-group elements (PGE) have been determined in sulfide minerals from zoned sulfide droplets of the Noril’sk 1 Medvezky Creek Mine. The aims of the study were; to establish whether these elements are located in the major sulfide minerals (pentlandite, pyrrhotite, chalcopyrite and cubanite), to establish whether the elements show a preference for a particular sulfide mineral and to investigate the model, which suggests that the zonation in the droplets is caused by the crystal fractionation of monosulfide solid solution (mss). Nickel, Cu, Ag, Re, Os, Ir, Ru, Rh and Pd, were found to be largely located in the major sulfide minerals. In contrast, less than 25% of the Au, Cd, Pt and Zn in the rock was found to be present in these sulfides. Osmium, Ir, Ru, Rh and Re were found to be concentrated in pyrrhotite and pentlandite. Palladium and Co was found to be concentrated in pentlandite. Silver, Cd and Zn concentrations are highest in chalcopyrite and cubanite. Gold and platinum showed no preference for any of the major sulfide minerals. The enrichment of Os, Ir, Ru, Rh and Re in pyrrhotite and pentlandite (exsolution products of mss) and the low levels of these elements in the cubanite and chalcopyrite (exsolution products of intermediate solid solution, iss) support the mss crystal fractionation model, because Os, Ir, Ru, Rh and Re are compatible with mss. The enrichment of Ag, Cd and Zn in chalcopyrite and cubanite also supports the mss fractionation model these minerals are derived from the fractionated liquid and these elements are incompatible with mss and thus should be enriched in the fractionated liquid. Gold and Pt do not partition into either iss or mss and become sufficiently enriched in the final fractionated liquid to crystallize among the iss and mss grains as tellurides, bismithides and alloys. During pentlandite exsolution Pd appears to have diffused from the Cu-rich portion of the droplet into pentlandite. 相似文献
12.
Edward M. Ripley 《Contributions to Mineralogy and Petrology》1979,69(4):345-354
Sulfide minerals in amounts up to 3 vol% are found in basal, chilled marginal zones of two layered peridotite-pyroxenite-gabbro sills in the Early Precambrian Deer Lake Complex, northcentral Minnesota. The sulfides occur interstitially to silicate minerals, and consist of pyrrhotite with minor exsolved cobaltian pentlandite, chalcopyrite, gersdorffite, and marcasite±pyrite as an alteration product of pyrrhotite.The basal chilled units (3–6 m) of the sills are divisable into three zones based primarily on textures. The lowermost zone is an equigranular basalt, whereas the overlying zone is characterized by skeletal, spinifex-like actinolite after clinopyroxene. The upper zone of the basal margins contains elongate and swallow tail plagioclase, and is barren of sulfide minerals.Electron microprobe analyses of sulfide minerals and modal data suggest that sulfide bulk compositions at 1,100–1,000 ° C represent a pyrrhotite solid solution and a coexisting Cu-rich sulfide liquid. Cooling of the Cu-rich liquid and low temperature transformations are thought to have produced chalcopyrite or chalcopyrite plus pyrrhotite. The sulfide minerals have reequlibrated to temperatures near 300 ° C or less.Analyses of sulfur content and 34S values suggest that assimilation of sulfur from adjacent country rocks was the principal mechanism responsible for anomalous concentrations of sulfides in the basal chilled margins. The distribution of sulfides in the peridotite-pyroxenite-gabbro portions of the sills, and calculations of settling rate preclude an origin involving gravitational settling of immiscible droplets through the magma body. 相似文献
13.
The paper presents concentrations of the platinum-group and chalcophile elements in the base metal sulfides (BMS) from the Jinchuan Ni–Cu sulfide deposit determined by laser ablation-inductively coupled plasma-mass spectrometry. Mass balance calculations reveal that pentlandite hosts a large proportion of Co, Ni and Pd (> 65%), and that pentlandite and pyrrhotite accommodate significant proportions of Re, Os, Ru, Rh, and Ag (~ 35–90%), whereas chalcopyrite contains a small amount of Ag (~ 10%) but negligible platinum-group elements. Iridium and Pt are not concentrated in the BMS and mostly occur in As-rich platinum-group minerals. The enrichments of Co, Ni, Re, Os, Ru, and Rh in pentlandite and pyrrhotite, and Cu in chalcopyrite are consistent with the fractionation of sulfide liquid and exsolution of pentlandite and pyrrhotite from the mono-sulfide solid solution (MSS). The Ir-bearing minerals exsolved from the MSS, depleting pentlandite and pyrrhotite in Ir, whereas sperrylite exsolved from the residual sulfide liquid on cooling. Diffusion of Pd from residual sulfide liquid into pentlandite during its exsolution from the MSS and crystallization of Pt-bearing minerals in the residual sulfide liquid resulted in the enrichment of Pd in pentlandite and decoupling between Pd and Pt in the Jinchuan net-textured and massive ores. 相似文献
14.
Concentrations of platinum group elements (PGE), Ag, As, Au, Bi, Cd, Co, Mo, Pb, Re, Sb, Se, Sn, Te, and Zn, have been determined
in base metal sulfide (BMS) minerals from the western branch (402 Trough orebodies) of the Creighton Ni–Cu–PGE sulfide deposit,
Sudbury, Canada. The sulfide assemblage is dominated by pyrrhotite, with minor pentlandite, chalcopyrite, and pyrite, and
they represent monosulfide solid solution (MSS) cumulates. The aim of this study was to establish the distribution of the
PGE among the BMS and platinum group minerals (PGM) in order to understand better the petrogenesis of the deposit. Mass balance
calculations show that the BMS host all of the Co and Se, a significant proportion (40–90%) of Os, Pd, Ru, Cd, Sn, and Zn,
but very little (<35%) of the Ag, Au, Bi, Ir, Mo, Pb, Pt, Rh, Re, Sb, and Te. Osmium and Ru are concentrated in equal proportions
in pyrrhotite, pentlandite, and pyrite. Cobalt and Pd (∼1 ppm) are concentrated in pentlandite. Silver, Cd, Sn, Zn, and in
rare cases Au and Te, are concentrated in chalcopyrite. Selenium is present in equal proportions in all three BMS. Iridium,
Rh, and Pt are present in euhedrally zoned PGE sulfarsenides, which comprise irarsite (IrAsS), hollingworthite (RhAsS), PGE-Ni-rich
cobaltite (CoAsS), and subordinate sperrylite (PtAs2), all of which are hosted predominantly in pyrrhotite and pentlandite. Silver, Au, Bi, Mo, Pb, Re, Sb, and Te are found predominantly
in discrete accessory minerals such as electrum (Au–Ag alloy), hessite (Ag2Te), michenerite (PdBiTe), and rhenium sulfides. The enrichment of Os, Ru, Ni, and Co in pyrrhotite, pentlandite, and pyrite
and Ag, Au, Cd, Sn, Te, and Zn in chalcopyrite can be explained by fractional crystallization of MSS from a sulfide liquid
followed by exsolution of the sulfides. The early crystallization of the PGE sulfarsenides from the sulfide melt depleted
the MSS in Ir and Rh. The bulk of Pd in pentlandite cannot be explained by sulfide fractionation alone because Pd should have
partitioned into the residual Cu-rich liquid and be in chalcopyrite or in PGM around chalcopyrite. The variation of Pd among
different pentlandite textures provides evidence that Pd diffuses into pentlandite during its exsolution from MSS. The source
of Pd was from the small quantity of Pd that partitioned originally into the MSS and a larger quantity of Pd in the nearby
Cu-rich portion (intermediate solid solution and/or Pd-bearing PGM). The source of Pd became depleted during the diffusion
process, thus later-forming pentlandite (rims of coarse-granular, veinlets, and exsolution flames) contains less Pd than early-forming
pentlandite (cores of coarse-granular). 相似文献
15.
The quasiequilibrium directed crystallization technique was used for experimental simulation of zoning characteristic of Cu-rich pyrrhotite-chalcopyrite and pyrrhotite-cubanite-mooihoekite-haycockite ores at the Oktyabr??sky deposit. Directed crystallization of samples I (Fe 32.55, Cu 10.70, Ni 5.40, S. 51.00, Pt = Pd = Rh = Ir= Au = Ag = 0.05 at %) and II (Fe 33.74, Cu 15.94, Ni 1.48, S. 48.75, Pt = Pd = 0.05 at %) was performed. These samples approximate average composition of the ore. Monosulfide (mms) and intermediate (iss) solid solutions progressively crystallized from the melt. The curves of ore element distribution in samples have been drawn. The partition coefficients (k) of ore elements between solid solutions and sulfide melt have been determined depending on melt composition. The paths of melt, mss, and iss compositions are supplemented by tie lines connecting compositions of equilibrium liquid and solid phases. The phase composition of samples after cooling was studied using an optical microscope, XRD, and microprobe. The zoning of sample I is described by the following sequence of phases: monoclinic pyrrhotite ?? hexagonal pyrrhotite + tetragonal chalcopyrite ?? tetragonal and cubic chalcopyrite + pentlandite + bornite. Crystallized sample II consists of four zones: (1) hexagonal pyrrhotite and isocubanite; (2) hexagonal pyrrhotite, cubanite, and pentlandite; (3) low-S pc-phase close to haycockite and pentlandite; and (4) mooihoekite, pentlandite, and bornite mixtures. This sequence corresponds to the secondary zoning, which reflects both the primary fractionation of components and the solid-phase reactions during cooling of the crystallized sample. The Rh, Ru, and Ir partition coefficients between mss and melt have been measured, and speciation of PGM in samples has been identified. The results obtained are compared with typical natural Cu-rich sulfide ore of the Oktyabr??sky deposit. 相似文献
16.
Sarah A. S. Dare Sarah-Jane Barnes Hazel M. Prichard Peter C. Fisher 《Mineralium Deposita》2011,46(4):381-407
Magmatic sulfide deposits consist of pyrrhotite, pentlandite, chalcopyrite (± pyrite), and platinum-group minerals (PGM).
Understanding the distribution of the chalcophile and platinum-group element (PGE) concentrations among the base metal sulfide
phases and PGM is important both for the petrogenetic models of the ores and for the efficient extraction of the PGE. Typically,
pyrrhotite and pentlandite host much of the PGE, except Pt which forms Pt minerals. Chalcopyrite does not host PGE and the
role of pyrite has not been closely investigated. The Ni–Cu–PGE ores from the South Range of Sudbury are unusual in that sulfarsenide
PGM, rather than pyrrhotite and pentlandite, are the main carrier of PGE, probably as the result of arsenic contribution to
the sulfide liquid by the As-bearing metasedimentary footwall rocks. In comparison, the North Range deposits of Sudbury, such
as the McCreedy East deposit, have As-poor granites in the footwall, and the ores commonly contain pyrite. Our results show
that in the pyrrhotite-rich ores of the McCreedy East deposit Os, Ir, Ru, Rh (IPGE), and Re are concentrated in pyrrhotite,
pentlandite, and surprisingly in pyrite. This indicates that sulfarsenides, which are not present in the ores, were not important
in concentrating PGE in the North Range of Sudbury. Palladium is present in pentlandite and, together with Pt, form PGM such
as (PtPd)(TeBi)2. Platinum is also found in pyrite. Two generations of pyrite are present. One pyrite is primary and locally exsolved from
monosulfide solid solution (MSS) in small amounts (<2 wt.%) together with pyrrhotite and pentlandite. This pyrite is unexpectedly
enriched in IPGE, As (± Pt) and the concentrations of these elements are oscillatory zoned. The other pyrite is secondary
and formed by alteration of the MSS cumulates by late magmatic/hydrothermal fluids. This pyrite is unzoned and has inherited
the low concentrations of IPGE and Re from the pyrrhotite and pentlandite that it has replaced. 相似文献
17.
The paper discusses the results of studying the contents of platinum group elements (PGE) and platinum group minerals (PGM) in ores of the Kingash deposit. The bulk of PGE has been established as concentrated in disseminated sulfide chalcopyrite–pyrrhotite–pentlandite ore and is represented by palladium bismuth–tellurides. During melt differentiation, the content and relationship of PGE are changed; the Pd/Pt value increases (up to 1.9 and 4.2 in dunite and wehrlite, respectively) with decreasing Mg number. The distribution of PGE, sulfur, and REE in various ore types suggests two formation mechanisms of high-grade ores: (1) the product of liquid immiscibility and gravity separation at the early magmatic stage and (2) involvement of the residual melt saturated in volatiles, which contributed to transportation and segregation of PGE at the late magmatic stage. The evolution of the ore system of the Kingash massif is characterized by sequential enrichment of PGM in Ni from high-Mg to low-Mg rocks similarly to sulfide minerals of disseminated ore. The criteria for ore content in utramafics of the Kansk block have been identified based on compared ore element and PGE concentrations in ultramafic rocks of the Kingash and Idar complexes. 相似文献
18.
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
19.
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