吉林小西南岔金铜矿床主要金属矿物的成因矿物学特征

本文通过对矿床中主要金属矿物黄铁矿、磁黄铁矿、黄铜矿的成因矿物学研究,指出黄铁矿中Co/Ni、S/Se、Se/Te、Au/Ag比值均显示出岩浆热液成因特征;黄铁矿、磁黄铁矿、黄铜矿的硫同位素组成具深源岩浆源流特征,并随成矿深度发生有规律的变化;黄铁矿、磁黄铁矿、黄铜矿中某些微量元素质量分数北山矿段与南山矿段之间有一定差...     

试论黄铁矿化学成分的标型意义

本文依据相关元素的分配和地球化学理论,讨论了各种热液成因黄铁矿中的Co、Ni、As、Sb、Cu、Pb、Zn、Au、Ag、Mn、Te、Se含量和Fe/S、Co/Ni、Pb/Zn、Au/Ag比率及其在时间上和空间上的变化趋向,并得出黄铁矿的化学成分在探索矿床成因、划分成矿阶段、研究矿床分带和矿化评价等方面具一定意义的结论。     

湘黔地区下寒武统黑色岩系中镍-钼矿床黄铁矿的成因

重点研究了贵州遵义中南村和湖南张家界三岔镍-钼多金属矿床的黄铁矿,矿床成因为热水喷流沉积型。黄铁矿样品S/Fe比值的平均值为2.0093~2.048,成分特征均属于铁亏损型,说明其形成温度低。Co/Ni变化范围为0.077~4.5,均值为2.197,据Co/Ni的比值可以判断本区的黄铁矿主要为热液成因,矿化物质来源为热水喷流体系内的热液。成分图解标型显示,黑色岩系中高ω(Co+Ni)/ω(Fe)的黄铁矿和高ω(As+Se+Te)/ω(S)的黄铁矿均大量出现,可能与热水喷流沉积的温差变化范围较大有关,而并非正常沉积的产物。S/Se比值为950.8~1059.9,说明生成环境均一程度较高,而且海水温度比较高。由中南村镍-钼矿床的Se/Te值也能判明其为热液成因。关于黄铁矿的研究对本区镍-钼矿床的寻找有重要意义。     

湘黔地区下寒武统黑色岩系中镍-钼矿床黄铁矿的成因

重点研究了贵州遵义中南村和湖南张家界三岔镍-钼多金属矿床的黄铁矿,矿床成因为热水喷流沉积型.黄铁矿样品S/Fe比值的平均值为2.0093-2.048,成分特征均属于铁亏损型,说明其形成温度低.Co/Ni变化范围为0.077~4.5,均值为2.197.据Co/Ni的比值可以判断本区的黄铁矿主要为热液成因,矿化物质来源为热水喷流体系内的热液.成分图解标型显示,黑色岩系中高ω(Co+Ni)/ω(Fe)的黄铁矿和高ω(As+Se+Te)/ω(S)的黄铁矿均大量出现,可能与热水喷流沉积的温差变化范围较大有关.而并非正常沉积的产物.S/Se比值为950.8-1059.9,说明生成环境均一程度较高,而且海水温度比较高.由中南村镍-钼矿床的Se/Te值也能判明其为热液成因.关于黄铁矿的研究对本区镍-钼矿床的寻找有重要意义.     

陕西凤县二里河铅锌矿床金属硫化物标型特征及地质意义

为寻找凤县二里河铅锌矿床成因类型证据,利用电子探针显微分析对二里河铅锌矿床金属硫化物进行分析,研究结果表明二里河铅锌矿床内黄铁矿含有两种不同类型:一种黄铁矿Co/Ni值为0.04～1.68,平均值为0.57,显示沉积成因(Co/Ni<1),矿物受后期热液熔蚀改造,形成时期较早;另一种黄铁矿Co/Ni值为0.98～7.6...     

西天山智博铁矿床黄铁矿成分特征及硫同位素研究

智博大型磁铁矿床位于新疆西天山阿吾拉勒铁铜成矿带东段,主要矿石矿物为磁铁矿,主要共生金属矿物为黄铁矿。文章通过对黄铁矿进行矿物成因研究来推测矿床成因及特征。本次研究选择2个成矿期的矿石及围岩中的黄铁矿进行电子探针及硫同位素研究。电子探针数据显示岩浆期黄铁矿w(Co)平均为4703×10~(-6),大于热液期w(Co)(735.71×10~(-6)),Co/Ni比值(平均18.53)也大于热液期黄铁矿Co/Ni比值(平均0.96);S/Se比值多数集中于1000～8000之间。部分Co/Ni、Se/Te、S/Se比值落入热液成因范围内,暗示了热液流体参与成矿的可能性。而Co-Co/Ni图解显示岩浆期矿石和热液期矿石具有一定的继承性。黄铁矿中δ~(34)S值介于-1.2‰和0.3‰之间,表明硫主要来源于幔源硫。智博铁矿床矿石主要为岩浆成因,但岩浆期后热液及其他热液流体也参与了晚阶段的成矿作用。     

甘肃花牛山铅锌银矿床成因：来自原位S、Pb同位素及微量元素的约束

甘肃花牛山铅锌银矿床位于中亚造山带中段的甘肃北山地区。本文在详细的野外观察和室内鉴定的基础上,将花牛山铅锌银矿床成矿阶段划分为石英-毒砂-黄铁矿(第Ⅰ成矿阶段)和石英-多金属硫化物(第Ⅱ成矿阶段)两个阶段;进一步将黄铁矿划分为三种类型,分别为第一种类型的胶状黄铁矿(Py0)、第二种类型的热液叠加交代特征的黄铁矿(Py Ⅰ)及第三种类型的热液黄铁矿(PyⅡ)。黄铁矿、磁黄铁矿的原位硫同位素研究表明,成矿从早到晚硫化物δ~(34)S值呈递增的规律,具有逐渐向岩浆硫演化的趋势;胶状黄铁矿δ~(34)S值为-9.37‰～-8.10‰,具有沉积(生物成因)硫的特征;成矿第Ⅰ阶段硫化物δ~(34)S值为-9.03‰～-7.03‰,成矿第Ⅱ阶段硫化物δ~(34)S值为-5.77‰～-4.88‰,成矿阶段具有沉积硫与岩浆硫混合来源的特征。黄铁矿、磁黄铁矿的原位铅同位素研究表明,成矿期硫化物的~(206)Pb/~(204) Pb值、~(207)Pb/~(204) Pb值、~(208) Pb/~(204) Pb值以及μ、ω等铅同位素特征值组成范围较窄,铅源为与岩浆作用有关的壳幔混合来源,且与壳幔混合来源的晚三叠世花岗岩中长石铅及其控制的矽卡岩型金矿硫化物铅同位素组成类似。黄铁矿原位微量元素研究表明,胶状黄铁矿(Py0) Co/Ni和S/Se 比值分别为0.004～0.34和3.43 × 10~4～34.84 × 10~4,Se含量为1.558 × 10~(-6)～15.82 × 10~(-6),表现为沉积成因黄铁矿的特征。具有热液叠加交代特征Py Ⅰ的Co/Ni和S/Se 比值分别为0.05～3.38、0.05 ×10~4～5.38 ×10~4,Se含量为10.09 × 10~(-6)～1070 × 10~(-6),数值分布范围广,总体上有别于沉积成因黄铁矿,类似于热液成因黄铁矿的特征。热液黄铁矿(Py Ⅱ)的Co/Ni和S/Se 比值分别为0.60-68.88、1.46 × 10~4～9.15 × 10~4,Se含量为5.938 × 10~(-6)-35.91 × 10~(-6),表现为热液成因的特征。综上研究,认为花牛山矿床经历了南华纪-震旦纪沉积胶状黄铁矿形成期和晚三叠世岩浆热液成矿期,胶状黄铁矿在成矿过程中提供了部分硫,成矿金属物质主要来自晚三叠世岩浆成矿热液,并认为矿床成因为岩浆热液型矿床。     

黄铁矿标型特征在找矿中的应用:以赵家堡子金矿为例

1概述黄铁矿是金矿床中常见的主要金属硫化物,同时也是金的主要载体矿物,因此研究黄铁矿标型特征对指导金矿的找矿非常重要。黄铁矿化学式为FeS2,常含有As、Co、Ni、Se、Te、Sb、Cu、Au、Ag等的细分散混入物。Co、Ni类质同象代替Fe,形成FeS2—CoS2和FeS2—NiS2系列,随Co、Ni代替Fe的含量增加,晶胞增     

广西大厂矿区黄铁矿的标型特征研究

本文从化学成分和物理性质方面对大厂黄铁矿进行了标型特征研究。指出大厂黄铁矿的标型特征是:高s/Fe值,高As、Se,低Co、Ni、Te,Co/Ni<1;热电系数高正值;晶胞参数a_0偏大;弱顺磁性。黄铁矿的微量元素特征表明矿床形成与岩浆热液有关,并反映了矿化演化的方向。应用黄铁矿的Sn/Cu比值可以区分矿区内不同的矿床类型。大厂锡矿体中锡石品位与黄铁矿含砷量呈正相关关系,因此,黄铁矿的高砷含量可作为寻找矿体内富锡地段的标志。     

攀西红格钒钛磁铁矿矿田富钴硫化物中钴的地球化学特征及其地质意义

攀西红格钒钛磁铁矿矿田白草矿区发育富钴硫化物矿物,关于其成因和形成环境方面的研究较为薄弱。本文采用矿物学、矿物化学、地球化学等方法对其进行系统研究。矿石中主要富钴硫化物为磁黄铁矿（Po）、黄铁矿（Py）、镍黄铁矿（Pn）、硫钴镍矿（Se）。磁黄铁矿Co、Ni平均质量分数分别为0.21%、0.42%,Co/Ni平均值为1.10;黄铁矿Co、Ni平均质量分数分别为0.18%、0.29%,Co/Ni平均值为0.77;镍黄铁矿Co、Ni平均质量分数分别为2.67%、34.30%,Ni/Fe平均值为1.08、S/Fe平均值为1.91、M/S^#平均值为1.13;硫钴镍矿Co、Ni平均质量分数分别为24.30%、22.90%,Co/Ni平均值为1.06。根据Po-Py矿物温度计,白草矿区富钴硫化物结晶温度在267~490℃之间,表明其形成于中高温的条件。通过与地幔包体镍黄铁矿S/Fe、M/S^#特征值的对比,结合磁黄铁矿具有陨硫铁（Tr）同质多象晶体的特征,认为白草矿区硫化物具有地幔源的特征,说明成矿物质来源于地幔。白草矿区钴地球化学特征研究表明,在硫化物熔体分离过程中,钴迁移至单硫化物固溶体形成Po-Py固溶体,再由Po-Py固溶体中迁移至Pn、Se,形成了Se、Pn、Po-Py、Ccp（黄铜矿）中Co质量分数依次递减的现象。     

浙江火山岩区金矿床黄铁矿的找矿矿物学研究

论文给出了中国浙江火山岩区金矿床中黄铁矿的微量元素、形态和物理性质找矿标型特征.例如.(在许多)浙江火山岩区重要金-银矿床中黄铁矿相对富含铅、锌、钼、锡、砷、锑、铋而贫钴,镍、硒、碲:并且S/Se、Ag/Au、Pb/Ni、Se/Te、(As+sb+Bi)/(Se+Te)比值较高,Co/Nj、Ag/Pb、Ag/Zn、Cu/Zn和(Co+Ni)/(Pb+Zn)比值较低,再如含金黄铁矿比不含金黄铁矿的反射率低.总之,黄铁矿的标型性研究对于寻找金矿具有重大的理论意义和实际意义.     

Extreme enrichment of Se,Te, PGE and Au in Cu sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion,east Greenland

The Platinova Reef, in the Skaergaard Intrusion, east Greenland, is an example of a magmatic Cu–PGE–Au sulfide deposit formed in the latter stages of magmatic differentiation. As is characteristic with such deposits, it contains a low volume of sulfide, displays peak metal offsets and is Cu rich but Ni poor. However, even for such deposits, the Platinova Reef contains extremely low volumes of sulfide and the highest Pd and Au tenor sulfides of any magmatic ore deposit. Here, we present the first LA-ICP-MS analyses of sulfide microdroplets from the Platinova Reef, which show that they have the highest Se concentrations (up to 1200 ppm) and lowest S/Se ratios (190–700) of any known magmatic sulfide deposit and have significant Te enrichment. In addition, where sulfide volume increases, there is a change from high Pd-tenor microdroplets trapped in situ to larger, low tenor sulfides. The transition between these two sulfide regimes is marked by sharp peaks in Au, and then Te concentration, followed by a wider peak in Se, which gradually decreases with height. Mineralogical evidence implies that there is no significant post-magmatic hydrothermal S loss and that the metal profiles are essentially a function of magmatic processes. We propose that to generate these extreme precious and semimetal contents, the sulfides must have formed from an anomalously metal-rich package of magma, possibly formed via the dissolution of a previously PGE-enriched sulfide. Other processes such as kinetic diffusion may have also occurred alongside this to produce the ultra-high tenors. The characteristic metal offset pattern observed is largely controlled by partitioning effects, producing offset peaks in the order Pt+Pd>Au>Te>Se>Cu that are entirely consistent with published D values. This study confirms that extreme enrichment in sulfide droplets can occur in closed-system layered intrusions in situ, but this will characteristically form ore deposits that are so low in sulfide that they do not conform to conventional deposit models for Cu–Ni–PGE sulfides which require very high R factors, and settling of sulfide liquids.     

Distribution of noble metals in ore mineral assemblages of the Volkovsky gabbroic pluton, central Urals

Relationships between noble-metal and oxide-sulfide mineralization during the origin of the Volkovsky gabbroic pluton are discussed on the basis of geochemical data and thermodynamic calculations. The basaltic magma initially enriched in noble metals (NM) relative to their average contents in mafic rocks, except for Pt, is considered to be a source of Pd, Pt, Au, and Ag in the gabbroic rocks of the Volkovsky pluton. The ores were formed with a progressive gain of NM in the minerals during the fractionation of the basaltic magma. The active segregation of NM in the form of individual minerals (palladium tellurides and native gold) hosted in titanomagnetite and copper sulfide ore occurred during the final stage of gabbro crystallization, when the residual fluid-bearing melt acquired high concentrations of Cu, Fe, Ti, and V, along with volatile P and S. Copper sulfides—bornite and chalcopyrite—are the major minerals concentrating NM; they contain as much as 22.65–25.20 ppm Pd and 0.74–1.56 ppm Pt; 4.39–8.0 ppm Au, and 127.2–142.6 ppm Ag, respectively. The copper ore and associated NM mineralization were formed at a relatively low sulfur fugacity, which was a few orders of magnitude (attaining 5 log units) lower than that of the pyrite-pyrrhotite equilibrium. The low sulfur fugacity and the close chemical affinity of Pd and Pt to Te precluded the formation of pyrrhotite, pyrite, and PGE disulfides. The major ore minerals and NM mineralization were formed within a wide temperature range (800–570°C), under nearly equilibrium conditions. Foreign elements (Ni, Co, and Fe) affected the thermodynamic stability of Pd and Pt compounds owing to the difference in their affinity to Te and to elements of the sulfur group (S, Se, and As). The replacement of Pd with Ni and Co and, to a lesser extent, with Pt and the replacement of Te with S, As, and Se diminish the stability field of palladium telluride. Comparison of Pd tellurides from copper sulfide ores at the Volkovsky and Baronsky deposits showed the enrichment of the former in Au, Sb, and Bi, while the latter are enriched in Pt, Ni, and Ag. The enrichment of Pd tellurides at the Baronsky deposit in Ni is correlated with the analogous enrichment of the host gabbroic rocks.     

山东七宝山金铜多金属矿区黄铁矿微量元素特征及其地质意义

七宝山金铜多金属矿区的钓鱼台硫铁矿床、金线头金铜矿床以及七宝山铅锌矿床,其矿化类型分别为似层状浸染型、隐爆角砾岩型、裂控热液脉型,黄铁矿是三类矿化中最发育的金属硫化物矿物。通过对3个矿床黄铁矿产状,晶体形态,主、微量元素的nS与nFe实际原子个数比图解(nS/nFe=1.985~2.066)、δFe与δS特征图解(δFe/δS=±5%)、δFe/δS-As图解、(Fe+S)-As图解、Co/Ni特征图解(Co/Ni=1.2~11;Co/Ni=2~27;0.7~18)、Co-Ni-As特征图解以及微量元素相关性[Se-Sb(0.528)、Se-Zn(0.371)、Zn-Sb(0.642)、Pb-Te(0.463)]等研究,得知3个矿床黄铁矿均受岩浆热液的影响,其成矿物质和岩浆作用密切相关,表明3类矿化黄铁矿均为与七宝山次火山杂岩体有关的中温热液型矿床。     

贵州遵义中南村黑色岩系黄铁矿的成分标型与成因探讨

对贵州遵义中南村黑色岩系多元素矿床黄铁矿中的Co、Ni、As、Se、Te、n(s)／n(Fe)、w(Co)／w(Ni)、w(S)／w(Se)、w(Se)／w(Te)等标型进行了研究,井将其与4个胶东热液型金矿的黄铁矿的相应数据进行了对比。通过成分标型分析,并结合黄铁矿的形态、内部结构和同位素特征以及前人的研究成果．认为此黑色岩系多元素矿床应为海底热水沉积和生物沉积混合成因。该黑色岩系黄铁矿同胶东界河金矿的黄铁矿、胶东金青顶金矿中的黄铁矿、胶东玲珑金矿西山矿区中的黄铁矿和胶东三山岛金矿床中的黄铁矿等热液金矿型黄铁矿在10000×w(Co+Ni)／w(Fe)-10000×w(As十Se十Te)／w(S)-100×(n(S)／n(Fe)-1.8)三角图上的投点明显不同,前者投点甚为分散,后者投点较集中。从成因角度分析认为：后者的物质来自花岗岩,主成矿过程受单一的温度变化范围不大的岩浆热液控制;前者物质来源复杂,受高温阶段的深部循环热水和低温阶段的海水一热水混合流体甚至生物作用的制约。由此可以初步提出以下一般判据：在10000×w(Co十Ni)／w(Fe)一10000×w(As十Se+Te)／w(S)一100x(n(S)／n(Fe)一1.8)三角图上,成因简单的黄铁矿的投点较集中,成因复杂的黄铁矿的投点较分散。     

Minor elements and ore genesis of the Fankou lead-zinc deposit,China

The Fankou Pb-Zn deposit occurs in the Middle-Upper Devonian and Lower Carboniferous carbonate and argillaceous carbonate formations. In principle, the deposit can be classified as a carbonate-hosted strate-bound deposit. Representative sphalerite, galena, and pyrite separates from Fankou have been analysed. For the purpose of comparison a literature survey on minor elements of other districts have been carried out. The comparison of determined data with the quoted data shows that the Fankou sphalerites are rich in Ga, Ge and Ag, but poor in Se and Te; the Fankou galenas are rich in Ag, Hg, Sb and As, but poor in Se, Te, Tl and Bi; the Fankou pyrites are rich in As, Cd and In, but poor in Se, Te, Co and Ni. Zn/Cd and Se/S×10^–4 ratios for sphalerites, Sb/Ag, Sb/Bi and Se/S×10^–4 ratios for galenas and Co/Ni ratios for pyrites from Fankou and other districts have been calculated. Ga-Ge-Ag atomic ratios in sphalerites, Sb-Bi-Ag atomic ratios in galenas and Co-Ni relations in pyrites have been plotted. The average value (311) of Zn/Cd ratios for sphalerites from Fankou is similar to values of sphalerites from Gaobanhe, Heqing, Accesa and Broken Hill. The average Sb/Ag ratio (0.74) and the Sb-Bi-Ag atomic ratios in Fankou galenas are similar to those in the syngenetic galena from the British Island. The Ga-Ge-Ag atomic ratios for Fankou sphalerites are similar to those for the syngenetic sphalerites and Gorno sphalerites. The average Co/Ni ratio (1.1) for micro to fine-grained pyrites from Fankou laminated-bedded pyrite ore is similar to that (0.8) for the sedimentary pyrites from other districts. As to the fine to medium-grained pyrites from Fankou massive pyritic ores, their higher Co/Ni ratios (1.6–1.8) may relate to the fact that more Ni is lost than Co, during the reformation or recrystallization. Sphalerite, galena and pyrite from Fankou all are rather poor in Se and have very low values of Se/S×10^–4, so they may bear no genetic relation to volcanism. To sum up, the following conclusions can be reached: (1) The Fankou deposit possesses some syngenetic features. (2) Evidently it differs from skarn type, hydrothermal type, and volcanogenic type deposits. (3) Surely it is a reformed sedimentary Pb-Zn deposit.     

Covellite of the Semenov-2 hydrothermal field (13°31.13′ N,Mid-Atlantic Ridge): Enrichment in trace elements according to LA ICP MS analysis

As a result of LA ICP MS analysis of sulfides of the Semenov-2 hydrothermal field, it is established that covellite, which replaces Zn sulfides, is enriched in most trace elements. The Ga, Ni, and In contents in it do not vary, whereas Mn, Co, and Cd are lower than in sphalerite. The distribution of trace elements in covellite, which replaces Cu–Fe sulfides, is distinct: it is enriched in Cd, Sb, Pb, and Bi, whereas the contents of other elements are either lower or invariant. Covellite, which replaces Zn sulfides, is enriched in all trace elements relative to that replacing Cu–Fe sulfides. Enrichment of covellite in trace elements relative to primary sulfides was favored by oxidation of the hydrothermal fluid by seawater, which is similar to the processes of submarine oxidation of ancient massive sulfide deposits. Covellite is also a host to invisible gold and silver in ores of the Semenov-2 field along with toxic elements such as As, Se, Te, Tl, and Cd.     

白银厂铜多金属矿田微量元素和稀土元素地球化学研究

与日本黑矿及现代海底火山岩为主岩矿床相比，白银厂矿田各类矿石，尤其是块状Ｚｎ－Ｐｂ－Ｃｕ矿石具有最高的Ａｓ和Ｂｉ含量，比较高的Ｇａ、Ｃｄ和Ａｕ含量，以及较高的Ａｕ／Ａｇ和Ｃｏ／Ｎｉ比值。该矿田矿石的Ａｕ含量与闪锌矿中铁含量呈负相关关系。小铁山矿床闪锌矿与日本黑矿的闪锌矿微量元素特征很相似。矿田各类矿石ＲＥＥ型式与细碧角斑岩类岩石基体相似，这说明矿石与岩石的物质来源基本一致。研究和对比表明，火山成因