Discipline progress of mineral mapping of gold deposit in China

Sanjiang and Jiaodong areas are the important gold regions in China. The gold mineralization is cor- related with the Mesozoic faults and its derivative faults in the granite or the contact zone between granite and base rock. The mineral mapping is one of the important approaches of prospecting mineralogy. The temporal and spatial band distribution of mineral, mineral combination and mineral typomorphism features are natural regularity rules, but this kind of band feature is sometimes hidden and thus in need of mineral typomorphism re- search and mapping to disclose this band feature and to serve for the prospecting of mineral. The changes of the mineral typomorphism feature are often embodied in the ＂ through＂ mineral, the typomorphism features of the through mineral change like the gradient toward the ore body, and the changes of the features are most obvious and strongest toward the orebodies. The new American mineralogy mapping indicates the weak change of the mineral composition or structure will lead to the change of the shape and wave length position of the specific ab- sorbent feature. Australian experiment lab investigation has held the reason of a series of mineral. The progress achievement of the remote sensing and computer analysis technology now permits a direct comparison directly between the lab and remote sensing data, so the good feature database of the experiment light spectroscopy can serve for drawing of the spacial distribution and remote sensing material. Mineralogy mapping raised the exten- sive emphasis in the international earth arena.     

大兴安岭北段富林矽卡岩铜矿床成因:印支期含矿岩浆源区特征、蚀变矿物学及勘查意义

新近发现的印支期富林矽卡岩铜矿床位于大兴安岭北段新林区新林镇东约90km。矿区发育与成矿直接相关的花岗岩和侵入花岗岩中的花岗斑岩,矿体主要赋存于花岗岩与古元古代兴安桥组大理岩和早奥陶世黄斑脊山组钙质粉砂岩接触带内。富林矿床矿化与矽卡岩密切相关,整个矿化过程可分为两期:矽卡岩期和石英-硫化物期,5个阶段:早期矽卡岩阶段、退化蚀变阶段、氧化物阶段、早期硫化物阶段和晚期硫化物阶段,其中铜矿化主要发生在早期硫化物阶段。硫化物主要包括黄铜矿和黄铁矿,并含少量闪锌矿、方铅矿、斑铜矿等。蚀变类型包括石榴子石-透辉石矽卡岩化、阳起石-透闪石矽卡岩化、绿帘石矽卡岩化、绿泥石化、绢云母-粘土化、钾长石化和局部角岩化。电子探针分析(EMPA)结果表明:矿区内的石榴子石属钙铝-钙铁榴石系列,主要为钙铁榴石,辉石为透辉石-钙铁辉石系列,以透辉石为主,闪石主要为透闪石、阳起石以及少量镁绿钙闪石和铁浅闪石,帘石为黝帘石-绿帘石系列。黑云母以镁铁黑云母和铁叶云母为主,绿泥石主要为密绿泥石和铁叶绿泥石,长石以正长石和钠长石为主。石榴子石成分剖面显示从核部到边部,石榴子石呈现出钙铝榴石和钙铁榴石交替变化的环带特征,且Fe~(3+)含量的逐渐升高暗示后期成矿流体氧逸度升高,结合黑云母Mg-Fe~(3+)-Fe~(2+)图解,说明富林矽卡岩型铜矿床形成于较强的氧化环境。锆石LA-ICP-MS U-Pb测年结果显示花岗岩形成于~253Ma,花岗斑岩形成于~244Ma,为大兴安岭地区一期新的成矿事件。锆石原位Hf同位素测试结果表明,花岗岩εHf(t)介于-1.60~2.23,花岗斑岩εHf(t)介于-3.53~1.90,二者均具有古老的两阶段模式年龄,结合前人对区域构造背景的研究,认为富林花岗质岩石可能来自于松辽地块和兴安地块后碰撞背景下俯冲板片断离软溜圈上涌导致古老下地壳的部分熔融并卷入少量地幔物质而形成的岩浆。花岗斑岩及与斑岩有关的脉状矿化和蚀变的出现暗示富林地区可能存在印支期的斑岩型矿床,此外结合石榴子石、辉石成分特征以及辉石Mn/Fe比值与世界矽卡岩矿床对比,指出富林矿区外围找矿应综合考虑铜、钼、铁、金、铅、锌等矿化组合。     

A Systematic Spectroscopic Study of Four Apollo Lunar Soils

A systematic spectroscopic study including Raman,Mid-IR,NIR,and VIS-NIR,is used to investigate four endmember lunar soils.Apollo soils(<45 μm) 14163,15271,67511,and 71501 were selected as endmembers to study,based on their soil chemistry,maturity against space weathering,and the sampling locations.These endmembers include an anorthositic highlands soil(67511),a low-Ti basaltic soil(15271) ,a high-Ti basaltic soil(71501),and a mafic,KREEPy,impact-melt-rich soil(14163) .We used a laser Raman point-counting pr...     

湖南宝山铅锌矿西部矿带银的工艺矿物学研究

湖南宝山铅锌矿西部矿区为中低温热液裂隙充填交代型铅锌银矿床。本文对该矿带银的工艺矿物学进行系统研究,利用多种现代分析技术手段,查明矿石中银的主要矿物种类、赋存状态和工艺特征。化学分析结果确定矿石中银的平均品位为156.6×10^-6;地质小样化学分析统计显示银含量在空间上呈现上部高、下部低,平面上北西和南西部较北东和南东高的特征;白云岩型、砂岩型、灰岩型、角砾岩型矿石的银平均含量分别为595.78×10^-6、247.97×10^-6、195.83×10^-6、169.73×10^-6,白云岩型矿石的银含量最高,角砾岩矿石的银含量最低;银与方铅矿关系密切,银和铅二者的含量总体表现出良好的趋同性,据此可预测高品位的铅矿石的银含量高。对光片进行显微镜下鉴定、扫描电镜以及电子探针分析,确定矿区的金属矿物主要是方铅矿、闪锌矿、黄铜矿和黄铁矿,初步查明矿石中的银矿物主要是银黝铜矿,其次是含银砷黝铜矿和含银方铅矿;该矿床银的存在形式主要有两种:一种是以独立矿物——银黝铜矿形式存在,这部分银含量为10.179%~13.579%,银的平均含量为12.061%;另一种是赋存于方铅矿中,这部分银含量为0.011%~0.127%,银的平均含量为0.069%。经银的物相分析、单矿物银含量分析和平衡配分计算,揭示银黝铜矿虽然含有较高品位的银,但因矿物含量较少,银的平衡配分低;方铅矿的银含量不高,但由于矿物含量高,平衡配分率达到84.78%,因此成为银的主要载体矿物。筛析实验也发现银与铅有较好的趋同性,进一步印证了银的主要载体矿物是方铅矿,并且银在细粒级中含量偏高。本研究提出,在选矿过程中要提高银的回收率,应重视细粒级中主金属元素铅、锌的回收。     

Transformation relationship among different magnetic minerals within loess-paleosol sediments of the Chinese Loess Plateau

The dominant magnetic minerals and carriers of magnetic signals within the Chinese Loess Plateau are magnetite, maghemite, hematite, and goethite. In this study, we investigated the provenance and evolution of magnetic minerals during loess pedogenesis, using X-ray diffraction (XRD) and optical and electron microscopy, including field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). Our results reveal that single- and multiphase mineral assemblages among magnetic minerals in the loess-paleosol sequence have been formed. Partial oxidation of coarse eolian magnetite has occurred in the desert source area and the oxidation degree is enhanced after deposition of the dust upon the Chinese Loess Plateau. This mode of origin resulted in a microtexture consisting of an inner magnetite core surrounded by a hematite rim, and strongly affected the magnetic characteristics of the loess. Goethite coexists with hematite in the loess and paleosol, and nanometer-scale hematite is formed upon goethite rims via dehydration. Our study provides direct mineralogical evidence of the magnetic record and paleoclimatic implications of the loess-paleosol sequence of the Chinese Loess Plateau. Supported by National Natural Science Foundation of China (Grant Nos. 40772032 and 40573054) and National Basic Research Program (Grant No. 2007CB815603)     

鲁西地区角闪石岩地球化学、矿物学特征及其地质意义

基性-超基性岩脉群通常形成于伸展构造背景,是示踪地幔源特征以及大陆和超大陆破裂的重要标志.鲁西地区角闪石岩为研究古元古代岩浆源和构造演化提供了一个窗口.本文对鲁西地区角闪石岩进行了岩相学、全岩地球化学及角闪石、黑云母电子探针原位分析.角闪石岩具板内构造环境,来自富集地幔.通过角闪石、黑云母成因分析,均具有幔源成因,角闪石结晶温度为702～781℃;结晶压力为29.8～228.8 MPa,结晶深度1～7.5 km,结晶时氧逸度变化范围在NNO+2.68到NNO+3.35之间.结合本次获得角闪石岩磷灰石U-Pb年龄为(1817±35)Ma,认为鲁西地区(1817±35)Ma处于板内拉伸环境,存在幔源岩浆上侵,已进入大陆裂解阶段.     

广西金牙金矿床石英的标型特征及其意义

本文通过对金牙金矿床石英的化学成分、包裹体、物理性质及稳定同位素等万面的矿物学特征研究,取得了有价值的成因信息和找矿标志。认为该矿床属浅成中低温地下热(卤)水渗滤型金矿床,成矿物质来源于地层围岩。还指出石英颗粒极细小,多为隐晶至微晶,自形程度低,呈白色或无色、透明;比重低,晶胞棱长a_o大而Co小、单位晶胞体积增大(与标准石英比);红外光谱有1个宽峰、4个吸收峰和2个强的特征峰的波段,具单峰或双峰发热光曲线(在50～350℃范围内);具结构铝,含Ca、Fe、Mn、Au、Ag、Co、Ni、Se、Te与∑REE等杂质元素,其中Au与Al成正相关,而Au与∑REE呈负相关;包裹体呈无色透明、个体细小且少,以液相为主.气液比低,且出现沸腾包体群,其含盐度低,无子矿物,Na、Ca较高,为富含CO_2,CH_4的Ca~(-2)-Na_a-HCO_3~1-Cl型地下热(卤-水(温度305～190℃、压力25669～16945kpa.深度小于1km);δ~(18)O、δ~(18)O_(H_2O)、δD值具大气降水特征,δ~(13)C值类似油田碳等特征,是找“金牙型”金矿的重要找矿标志。     

贵州威宁沉积型赤铁矿矿石工艺矿物学研究

对贵州威宁沉积型赤铁矿石进行了工艺矿物学研究,重点研究了该矿石的矿物组成、主要矿物嵌布特征和主要含铁矿物赤铁矿的单体解离情况。研究表明,该矿石属于低磷、低硫、微细粒嵌布的赤铁矿石;矿石中主要铁矿物以赤铁矿为主,其次为磁铁矿和褐铁矿,主要脉石矿物以石英为主,其次为绿泥石、云母、高岭石等粘土矿物;赤铁矿嵌布粒度极细,平均粒度0.015mm,且赤铁矿与脉石矿物嵌布关系复杂。本研究为该矿石的开发利用提供基础资料。     

A ferrotantalite-ferrotapiolite intergrowth from Spittal a.d. Drau,Carinthia, Austria

Summary Intimate intergrowths of ferrotantalite and ferrotapiolite occur in a pegmatite in Spittal a.d. Drau, Carinthia. They are associated with muscovite, albite, smoky quartz, cassiterite, and microscopic uranmicrolite, zircon and uraninite. An assemblage of secondary uranium minerals is also present, generated by extensive alteration and leaching of the uranmicrolite and zircon. Textures of the ferrotantalite-ferrotapiolite intergrowths suggest considerable recrystallization that obliterated most of their primary features; neither coprecipitation nor exsolution can be recognized with certainty. Despite intersecting tielines indicating disequilibrium, the ferrotantalite and ferrotapiolite compositions show very restricted ranges (Mn/(Mn + Fe) 0.08–0.11, Ta/(Ta + Nb) 0.53–0.57 for ferrotantalite, and 0.01–0.04, 0.84–0.89 for ferrotapiolite, respectively), particularly in comparison with compositions from other localities featuring primary textures. A degree of compositional equilibration could have been attained during recrystallization. This process may also explain the high level of structural order characterizing both minerals; they are considerably disordered in other localities. Extensive deformation typical of pegmatites in the southern Ostalpen in general, and specifically of the Spittal pegmatite, is probably responsible for the recrystallization phenomena in the Ta, Nb, Sn-bearing mineral assemblage.

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Eine Ferrotantalit-Ferrotapiolit Verwachsung von Spittal a.d. Drau, Kärnten, österreich

Zusammenfassung In einem Pegmatit von Spittal a.d. Drau, Kärnten, treten enge Verwachsungen von Ferrotantalit und Ferrotapiolit auf. Diese werden von Muskovit, Albit, Rauchquarz, Zinnstein sowie-in mikroskopischem Masstab-von Uranmikrolith und Zirkon begleitet. Die Textur der Verwachsungen lässt Rekristallisation erheblichen Ausmasses erkennen, die die primären Merkmale weitgehend auslöscht. Weder eine gemeinsame Auskristallisation der beiden Mineralphasen noch eine Bildung durch Entmischung kann mit Sicherheit erkannt werden. Trotz einander kreuzender Verbindungslinien, die einen Hinweis auf Ungleichgewicht darstellen, zeigen die Zusammensetzungen des Ferrotantalits und des Ferrotapiolits lediglich geringe Schwankungsbreiten: Mn/(Mn + Fe) 0,08–0,11, Ta/(Ta + Nb) 0,53–0,57 für den Ferrotantalit beziehungsweise 0,01–0,04 und 0,84–0,89 für den Ferrotapiolit. Dies gilt insbesondere für den Vergleich mit Zusammensetzungen solcher Mineralphasen mit jenen von Fundarten, die primäre Verwachsungstrukturen aufweisen. Bis zu einem gewissen Ausmass ist diese homogene Zusammensetzung möglicherweise auf die Rekristallisation zurück zuführen. Diese Rekristallisation könnte auch den hohen strukturellen Ordnungsgrad der beiden Mineralphasen erklären. An anderen Fundorten zeigen diese Minerale strukturell merklich geringeren Ordnungsgrad. Intensive metamorphe überprägung, wie sie für die Pegmatite in den südlichen Ostalpen und insbesondere für jenen von Spittal typisch sind, kann wahrscheinlich als Ursache der Rekristallisationsphänomene der Ta-Nb-Sn Mineralparagenese angenommen werden.

     

新疆西天山智博铁矿岩浆-热液成矿作用—来自安山岩矿物学的证据

本文以智博铁矿区内的安山岩为研究对象,通过详细的野外地质调查,并利用电子显微镜和电子探针,对安山岩中的主要矿物进行了系统的岩相学观察和矿物学研究。研究表明,智博安山岩中斜长石主要为Na-高钠长石,具低TiO2,高Na2O和Al2O3的特点;辉石主要为普通辉石,具高TiO2,高Al2O3的特点;角闪石主要为镁角闪石和阳起石,具低TiO2和Al2O3,高MgO的特点;副矿物磁铁矿具高TiO2,低MgO和Al2O3的特点。辉石、角闪石矿物化学特征表明,智博铁矿安山岩的母岩浆属于壳幔混源的玄武质岩浆,构造环境为火山岛弧环境。智博安山岩中单斜辉石结晶温度为1225℃左右,结晶压力约0.795GPa,结晶深度约26km。智博铁矿后期的热液作用也参与了磁铁矿成矿,对智博铁矿的成矿有一定的贡献。