广西茶山辉铁锑矿的初步研究

辉铁锑矿产于广西茶山矿区28号脉。脉中主要矿物共生组合是毒砂-黄铁矿,方铅矿-闪锌矿,辉铁锑矿-辉锑矿及石英-辉锑矿。其爆裂温度为:265—210℃,203—187℃,202—180℃,124—120℃。此外,还有少量石英-白钨矿及铅锑硫盐矿物组合。 辉铁锑矿呈柱状或针状自形晶,具强的双反射和反射多色性。计算分子式为Fe_(0.93-1.07) Sb_(2-2.17)S_4,含少量As、Sn、Au.X射线衍射的强线有、(100)3.6405,(80)3.1643,(80)2.9901,(80)2.5996。晶胞参数 α=11.46,b=14.04,c=3.74。 辉铁锑矿的穆斯堡尔谱是一个对称的四级双峰。其同质异能位移=0.788—0.822mm/s,四级分裂=2.66—2.727mm/s,穆斯堡尔谱的研究表明,辉铁锑矿中的铁为Fe~(2 )并处于畸变八面体中;Fe~(2 )与S为离子键合。这与晶体结构的研究是一致的。     

天然磁铁矿中铁的占位分布和类质同象替代的穆斯堡尔研究

磁铁矿是一种重要的常见矿物。人们用穆斯堡尔方法对磁铁矿已经做了一些研究。在室温下,磁铁矿的穆斯堡尔谱由两套六线谱组成。通常它们被分别指派给A位上的Fe~(3 )和B位上的Fe~(2 )与Fe~(3 )。等曾对这种指派提出不同看法,讨论了几种可能的指派方法。大多数天然磁铁矿的情况比组份简单的、正分的磁铁矿要复杂得多。它们常     

攀西地区某些花岗岩体中云母的穆斯堡尔效应研究

一、引言穆斯堡尔光谱学做为一种研究矿物的新方法,已经广泛地用在矿物学的研究中(应育浦和李哲,1977)。可以使用铁的穆斯堡尔效应来确定矿物中铁的价态、配位数、阳离子铁的分布,即有序和无序等。迄今已对几乎所有的含铁矿物进行过穆斯堡尔测试和研究。云母是一种重要的层状硅酸盐类矿物,它是花岗岩中的主要造岩矿物之一。近年来云母类矿物的穆斯堡尔效应研究已相当广泛,尤其对黑云母研究较多。本文收集了四川攀西地区某些不同地点,不同花岗岩体中十二个黑云母和二个白云母样品进行了化学分析和穆斯堡尔效应研究,以探讨黑云母、白云母中     

关于金在硫化物中赋存状态研究的某些新进展

毒砂和黄铁矿混合样品中“不可见金”的穆斯堡尔谱不同于纯金的和金在硫化物中呈分散的极细小亚颗粒的吸收谱,也不同于金的已知化合物的穆斯堡尔谱,揭示了金不仅能以极细的分散的自然金(即金属态)形式存在于硫化物中,而且还可以非金属态的不可见形式出现。     

浙江某金银矿床黃铁矿的穆斯堡尔谱参数及其地质意义

本文根据黄铁矿及有关矿物的晶体结构和穆斯堡尔谱参数的特点、对浙江某金银矿床及有关矿床的黄铁矿中杂质元素含量及其对黄铁矿结构与穆斯堡尔谱参数的影响,得出黄铁矿的四极分裂值QS的变化主要由黄铁矿中呈类质同象存在的杂质元素的含量不同所致的结论。由于黄铁矿中这些杂质元素的含量具有指示矿床成因、矿化阶段、矿床分带以及矿物组合的意义,因而黄铁矿的穆斯堡尔谱参数也就具有这些方面的意义,这可作为黄铁矿的一个新的标型特征并可在矿床的找寻、评价和勘探工作中应用。     

西藏甲玛铜多金属矿床磁黄铁矿标型矿物学特征及其地质意义

甲玛矿床位于冈底斯成矿带东段,是西藏地区最大的铜多金属矿床之一。磁黄铁矿是甲玛矿床最常见的金属矿物之一,其标型特征不仅反映其自身形成环境,对其形成机制和矿床成因也具有指示意义。文章选取产于不同岩性中的磁黄铁矿矿石样品,利用矿相学、X射线衍射和电子探针分析等手段对磁黄铁矿的形态、成分和结构进行了分析研究。研究表明,甲玛矿床的磁黄铁矿主要分布在距离岩体中心较远的矿区远端矽卡岩和角岩中。磁黄铁矿的晶胞参数和粉晶X射线衍射曲线显示矽卡岩中的磁黄铁矿主要为高温六方磁黄铁矿,角岩中的磁黄铁矿为高温六方磁黄铁矿和低温单斜磁黄铁矿的交生体,但主要以低温单斜磁黄铁矿为主。通过对矽卡岩和角岩中的磁黄铁矿进行电子探针测试,结果显示:矽卡岩中的磁黄铁矿中w(Fe)为60.09%～60.71%,平均为60.38%,w(S)为38.18%～38.69%,平均38.35%,化学分子式为Fe_8S_9～Fe_(10)S_(11);角岩中的磁黄铁矿中w(Fe)为59.05%～59.57%,平均为59.10%,w(S)为39.28%～39.95%,平均39.59%,化学分子式为Fe_5S_6～Fe_7S_8。根据以上矿物学特征,笔者进一步探讨了该矿床磁黄铁矿的沉淀机制:炽热的岩浆热液上涌,与碳酸盐岩地层和碎屑岩地层接触发生相互作用,并有大气水的加入,使得成矿流体在角岩中先快速降温,形成高温六方磁黄铁矿和低温单斜磁黄铁矿的交生体。同时,大量的含矿热液形成,并充填于有利的成矿空间(主要为层间破碎带)沉淀成矿,形成矽卡岩矿体,然后流体在矽卡岩矿段中经历缓慢降温,形成高温六方磁黄铁矿。结合矿床地质特征和相关元素地球化学特征,认为甲玛矿床类型为斑岩-矽卡岩型。     

黑云母的穆斯堡尔谱学及其在两类不同成因花岗岩体研究中的应用

在等加速穆斯堡尔谱仪上,用25毫居里Pd衬底的~(57)Co放射源测试了25个岩体中54个黑云母的穆斯堡尔谱。Fe~(2 )为四极分裂(Q.S.)值较大的一组不对称强双峰,而Fe~(3 )则为Q.S.值小的一组不对称弱双峰。用最小二乘法计算拟合成劳伦兹线型谱表明,Fe~(2 )和Fe~(3 )在晶格中分别有两个八面体M_1和M_2晶位,但部分样品中Fe~(3 )则占据了M_1和四面体T晶位。它们均属三八面体型为主的黑云母类型。由于黑云母样品分别产出于不同成因类型(同熔型、改造型,同熔型 改造型)的花岗岩体中,反映在穆斯堡尔参数值上存在着规律性的变化。从同熔型到改造型的黑云母中,Fe~(2 )M_1和M_2位的Q.S.值逐渐减少,但I.S.值在M_1位中略有增加;Fe~(3 )M_1位的Q.S.值和I.S.值则逐渐地减少。在改造型岩体的黑云母中Fe~(3 )仅见于M_2位,而在同熔型岩体的黑云母中Fe~(3 )则占据T晶位。     

一个拟合地质样品复杂穆斯堡尔谱的计算机程序

本文叙述了一个适合于地质样品复杂穆斯堡尔谱的计算机程序。它用FORTRAN-Ⅳ语言编写,并有一些约束条件可供选用。在CROMEMCO-Ⅲ微型计算机系统上使用本程序曾处理了一般常见地质样品的穆斯堡尔谱数据,如:钛铁矿、辉石、绿辉石、角闪石、蓝铁矿、十字石、海绿石、黑云母、赤铁矿、磁铁矿及磁黄铁矿等,均取得了良好的结果。     

磁铁矿的穆斯堡尔谱研究

我们对大冶、马坑、大顶、黄沙坪、鞍山五个矿区的七个铁矿石样品中的磁铁矿作了室温~(57)Fe和~(119)Sn穆斯堡尔谱测定,并根据穆斯堡尔数据和化学分析推算出磁铁矿的非理想配比的分子结构式. 初步研究表明,不同的成矿条件和Zn、Mg等二价阳离子的类质同像替代的多少,明显地影响晶胞参数和穆斯堡尔参数.文中讨论了它们的变化规律性.     

几个天然镁铝榴石的穆斯堡尔效应的研究

穆斯堡尔效应是一种无反冲的核γ射线的共振吸收现象,它是1958年由穆斯堡尔(R.L.M(?)ssbauer)发现的。由于穆斯堡尔效应产生的γ射线共振吸收谱线的能量宽度接近原子核能级的自然线宽,以及无反冲γ射线共振吸收(或散射)对γ射线能量变化十分灵敏,因此,可以把共振吸收的原子核当做灵敏的探针,测量固体中有关的原子核与核所在位置上固体的化学环境间的超精细相互作用。近些年来,穆斯堡尔效应已广泛应用于物理学、化学、生物学及矿物学的研究中来,穆斯堡尔谱仪已成为这些学科的重要研究工具之一。     

XPS identification of bulk hole defects and itinerant Fe 3d electrons in natural troilite (FeS)

XPS measurements have been made of vacuum-fractured monoclinic pyrrhotite and troilite that highlight sulfur coordination (S 2p) and iron electronic state (Fe 2p) differences between these two minerals as a result of iron lattice site occupancy. Metal-like Fe states are observed in the Fe 2p spectrum of troilite due to increased occupancy of Fe lattice sites and increased Fe-Fe 3d orbital interaction within the constraints of the mineral structure. Additional electron population near the top of the troilite valence band is confirmed by XPS measurement. These results provide comprehensive experimental evidence for itinerent 3d electrons in the natural iron sulfides.     

异性石中平面四配位Fe^2＋的穆斯堡尔谱研究

除硅铁钡矿之处，性石是迄今仅知的另一种含有平面四配位Ｆｅ＾２＋的矿物，异性石晶体样品为玫瑰色，透明，有油脂光泽，取自一花岗岩标本，异性石中平面四配位Ｆｅ＾２＋的穆斯堡尔参数：化学位移＝０．７８５（ｍｍ／ｓ）（相对天然铁），四极矩分裂＝０．４１９（ｍｍ／ｓ），明显地低于大多数硅酸矿物中的Ｆｅ＾２＋，但和硅铁钡矿的Ｆｅ＾２＋十分相近，本文对硅酸盐矿物Ｆｅ＾２＋的穆斯堡尔参数与配位数之间的关系做了讨论。     

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。     

单斜星叶石矿物的穆斯堡尔光谱学研究

本文对产于俄罗斯希宾地区的单斜星叶石进行了不同的温度条件下的穆斯堡尔光谱效应研究,通过在温度分别在298 K,180 K和80 K条件下的分析,发现单斜星叶石由2个Fe~(2 )和1个Fe~(3 )四极双峰组成,并进行了单斜星叶石中的畸变参数包括八面体键角(σ~2)和键长变量(Δ)的计算。但是,在两个畸变参数之间存在着明显的差异,将无法对它们的穆斯堡尔参数和四极双峰进行指派。本文对温度在同质异能位移和四极分裂中的作用进行了探讨,根据通过穆斯堡尔效应和f(Fe~(3 )(O))/f(Fe~(2 )(O))的平均值获得的三价铁对全铁的比值,改写了单斜星叶石的化学式。     

Mineralogy and texture of Fe-Ni sulfides in CI1 chondrites: Clues to the extent of aqueous alteration on the CI1 parent body

To better understand the role of aqueous alteration on the CI1 parent body, we have analyzed the texture, composition and mineral associations of iron nickel sulfides in four of the five known CI1 chondrites.The most commonly-occurring sulfide present in the CI1 chondrites is the iron-deficient Fe,Ni sulfide pyrrhotite ([Fe,Ni]_1−xS), that has a composition close to that of stoichiometric troilite (FeS). Three of the CI1s (Alais, Ivuna and Tonk) also contain pentlandite ([Fe,Ni]₉S₈), although pentlandite is a rare phase in Ivuna. Cubanite (CuFe₂S₃) was found in both Alais and Ivuna in this study, although it has also been reported in Orgueil (MacDougall and Kerridge, 1977). The pyrrhotite grains in all four chondrites form hexagonal, rectangular or irregular shapes, and show no evidence of Ni or Co zoning. The pyrrhotite grains in Orgueil and Ivuna are, in general, smaller, and show more “corrosions,” or “embayments,” than those in Alais or Tonk.We suggest that the precursor sulfide present in the CI1 chondrites was troilite which, during brecciation and oxidation on the parent body at a temperature of 100°C or less, converted the troilite to magnetite and pyrrhotite with pentlandite inclusions. Subsequently, continued alteration on the parent body removed pentlandite—partially from Alais, Tonk and Ivuna, completely from Orgueil—leaving behind pyrrhotite with spaces (“corrosions”) where the pentlandite had been. Ni derived from the pentlandite was incorporated into ferrihydrite, onto the surface of which the Ni,Na sulfate Ni-bloedite formed.Based on the size and abundant “corrosions” within pyrrhotite grains, combined with observations from other authors, we conclude that Orgueil and Ivuna have undergone a greater degree of alteration than Alais and Tonk. Further work is needed to assess the conditions under which pentlandite would be dissolved preferentially to pyrrhotite, as the study of terrestrial literature indicates that the latter mineral is preferentially removed.     

Evidence for aqueous activity on comet 81P/Wild 2 from sulfide mineral assemblages in Stardust samples and CI chondrites

The discovery of nickel-, copper-, and zinc-bearing iron sulfides from comet 81P/Wild 2 (Wild 2) represents the strongest evidence, in the Stardust collection, of grains that formed in an aqueous environment. We investigated three microtomed TEM sections which contain crystalline sulfide assemblages from Wild 2 and twelve thin sections of the hydrothermally altered CI chondrite Orgueil. Detailed structural and compositional characterizations of the sulfide grains from both collections reveal striking similarities. The Stardust samples include a cubanite (CuFe₂S₃) grain, a pyrrhotite [(Fe,Ni)_1−xS]/pentlandite [(Fe,Ni)₉S₈] assemblage, and a pyrrhotite/sphalerite [(Fe,Zn)S] assemblage. Similarly, the CI-chondrite sulfides include individual cubanite and pyrrhotite grains, cubanite/pyrrhotite assemblages, pyrrhotite/pentlandite assemblages, as well as possible sphalerite inclusions within pyrrhotite grains. The cubanite is the low temperature orthorhombic form, which constrains temperature to a maximum of 210 °C. The Stardust and Orgueil pyrrhotites are the 4C monoclinic polytype, which is not stable above ∼250 °C. The combinations of cubanite and pyrrhotite, as well as pyrrhotite and pentlandite signify even lower temperatures. The crystal structures, compositions, and petrographic relationships of these sulfides constrain formation and alteration conditions. Taken together, these constraints attest to low-temperature hydrothermal processing.Our analyses of these minerals provide constraints on large scale issues such as: heat sources in the comet-forming region; aqueous activity on cometary bodies; and the extent and mechanisms of radial mixing of material in the early nebula. The sulfides in the Wild 2 collection are most likely the products of low-temperature aqueous alteration. They provide evidence of radial mixing of material (e.g. cubanite, troilite) from the inner solar system to the comet-forming region and possible secondary aqueous processing on the cometary body.     

川西义敦措莫隆含锡花岗岩铁叶云母矿物学研究

通过对摸莫隆花岗岩中铁叶云母的矿物学研究，可得出如下结论：①可利用铁叶云母中的化学成分及H2O^＋，F^-,Cl^-来表征岩浆期后热液的性质和成岩成矿条件；②穆斯堡尔谱证实有3345%的Fe^3 进入四面体，并据此修正铁叶云母的晶体化学经验式；③Fe^2 的I.S，Q.S值与Fe/(Fe Mg)呈正相关，可定性反映其形成时温度和fo2;④Fe^2 在M1，M2晶位上的有序度能反映岩浆结晶温度高低和冷却速度快慢；⑤铁叶云母b0值大小主要与Fe^3 多少有关；⑥根据铁叶云母的化学成分判断措莫隆花岗岩属于含锡花岗岩；⑦根据铁叶云母的红外光谱及差热分析特征判断措莫隆花岗岩属于壳源型岩浆成因。     

氮气气氛下黄铁矿热分解的矿物相变研究

通过差热-热重分析、X射线粉末衍射（XRD）及磁化率分析等手段,对天然黄铁矿样品在氮气中受热发生的矿物相 变过程进行了综合研究。不同温度下黄铁矿煅烧产物的XRD物相分析结果显示,低于500℃时,黄铁矿无显著变化;随着 温度的升高（500~600℃）,黄铁矿开始转变为单斜磁黄铁矿,进而生成六方磁黄铁矿,磁化率显著升高;700℃~800℃的 煅烧产物主要为六方磁黄铁矿,磁化率明显下降,直至900℃进一步形成更稳定的陨硫铁（FeS）,磁化率接近于零。在黄 铁矿物相开始转变的温度（500~600℃）区间,黄铁矿生成单斜磁黄铁矿的速率大于单斜磁黄铁矿转化为六方磁黄铁矿的速 率;高温（700~900℃）时,黄铁矿转化为单斜磁黄铁矿的速率低于单斜磁黄铁矿转化为六方磁黄铁矿的速率,表现为黄铁 矿直接生成六方磁黄铁矿。     

A comparison of the dissolution behavior of troilite with other iron(II) sulfides; implications of structure

Further knowledge as to the nature of the structure of a terrestrial sample of troilite, FeS [stoichiometric iron(II) sulfide] is revealed by a combination of XPS studies and dissolution studies in acid. The XPS analysis of a pristine troilite surface (the sample being cleaved under high vacuum) is compared to that of a surface polished in an inert atmosphere and a surface after reaction in deoxygenated acid. Further comparison is made with polished and acid-reacted surfaces of pyrrhotite (Fe_1-xS) and pyrite (FeS₂). The pristine troilite S2p spectrum comprises mainly monosulfide 161.1 eV, within the reported range of monosulfide, together with evidence of an unsatisfied monosulfide surface state arising from S-Fe bond rupture. Small, higher oxidation state sulfur contributions, including a disulfide-like state are also present, which suggest the presence of defects due to some nonstoichiometry. The dissolution studies showed that the troilite, in addition to dissolving in acid as an ionic solid to produce H₂S, also exhibits some oxidation of sulfur in the surface layers. In addition, a study of the dissolution behavior of troilite under the influence of cathodic applied potential supported the existence of a proportion of the sulfur within troilite needing reduction before dissolution forming HS⁻ or H₂S can occur. A significant increase in the dissolution rate was observed with application of −105 mV (SHE), but further stepped decreases in potential to −405 mV and −705 mV resulted in a decreased rate of dissolution, a response typical of an ionic solid. The results of the studies emphasise the viewing of iron(II) sulfides as a continuum. Pyrrhotite has been reported previously to dissolve in acid both oxidatively (like pyrite) and nonoxidatively (like troilite) on the same surface. Dissolution studies using troilite, in Ar-purged acid, indicate that dissolution of this material may not be uniformly nonoxidative. XPS evidence of restructuring of the surface of troilite to pyrrhotite and the surface of pyrrhotite towards a FeS₂ type structure, after exposure to Ar-purged acid, is presented.     

钻孔岩心红外光谱-便携式XRF-磁化率测试在攀西太和钒钛磁铁矿床勘查中的应用

近年来,红外光谱技术因其可以绿色、快速、无损、精确探测矿物和提高勘查效率而备受关注.攀西超大型太和钒钛磁铁矿床位于镁铁质-超镁铁质层状岩体中,该矿床的典型矿物的红外光谱特征研究相对缺乏,制约了勘查效率的提高.本文应用便携式傅里叶变换红外光谱仪对四川太和钒钛磁铁矿床钻孔ZK1307岩心开展热红外光谱测试工作,并辅以便携式...