新疆包古图地区金矿床矿化类型和与围岩关系研究

西准噶尔包古图地区是新疆北部重要的金铜产地,已发现中型金矿床1处,金矿点20余处,大型斑岩铜（金、钼）矿床1处。金矿床按矿化类型可分为石英脉-蚀变岩型、蚀变岩型、辉锑矿-石英脉型、富硫化物型以及产于斑岩型铜矿中的伴生金。石英脉-蚀变岩型是最主要的矿石类型,构成包古图地区最主要的经济矿体。蚀变岩型是包古图地区近年来发现的新矿化类型,矿体由就位于NW向断裂中的蚀变凝灰质细砂岩和蚀变凝灰岩组成。辉锑矿-石英脉型矿石中含自然砷、自然锑、Paakkonenite、方锑金矿和硫锑金银矿等罕见矿物,这些矿物都与金矿化直接相关。富硫化物型矿石中,自然铋和辉铋矿与金矿化紧密相关。这些金矿化在空间上与中酸性岩体和岩体附近的岩脉关系紧密,成因上金矿化与岩体密切相关,而与岩脉关系不大。成矿元素在岩体中含量最高,其次为岩体附近的火山碎屑沉积岩,同一区域内岩脉的成矿元素含量最低,离岩体越远,成矿元素含量越低。Au与As、Sb、Bi之间具有不同程度的正相关性,As、Sb、Bi异常是该区找金的重要化探标志。中酸性岩体是最重要的找矿标志,岩体附近的断裂系统是金矿最有利的就位空间。     

新疆康古尔金矿成矿阶段及其年代学

根据矿床的地质特征，矿脉穿插关系，矿物共生组合及矿石Rb─Sr等时线，Sm─Nd等时线、40Ar／39Ar年龄谱等年代学资料，认为康古尔金矿热液成矿过程主要经历了4个成矿阶段。Ⅰ为磁铁绿泥蚀变岩成矿阶段；Ⅱ为黄铁矿石英脉成矿阶段；Ⅲ为多金属硫化物石英脉成矿阶段；Ⅳ为碳酸盐石英脉矿化阶段。矿化类型以蚀变岩型为主。     

一种重要的稀有金属矿床类型——斑岩型稀有金属矿床

近年来,随着地质工作的不断深入,斑岩型矿床(如斑岩铜矿、斑岩钨矿、斑岩钼矿、斑岩锡矿等)不断为人们所发现,其共同特点如下:1.矿化赋存在中—酸性浅成或超浅成的侵入岩体内,岩体形态多呈岩株、岩瘤、岩筒、岩脉、岩漏斗状。岩石普遍具斑状结构。2.矿石呈细脉浸染状及浸染状。矿石中     

山东招远界河金矿床矿化垂向变化特征研究

界河金矿床作为胶东地区典型的蚀变岩型金矿床,目前通过坑道工程揭露已经探明其矿体垂深达800m左右。从矿区浅部向深部,其矿化呈现出一定的规律性变化:矿化类型呈现出浅部以蚀变岩型矿化为主、深部以裂隙脉型矿化为主的分带规律;矿体规模逐渐变小,矿化强度逐渐减弱,矿体产状也逐渐变缓。此外,矿物组分、矿石组构、围岩蚀变以及微量元素特征等从浅部向深部也均呈现出规律性的变化。结合区域内石英脉型和蚀变岩型金矿化的垂向分带特征,初步建立了胶东地区金矿化在垂向上的"三段式"分带模式:浅部以石英脉型矿化为主,中部以蚀变岩型矿化为主,深部则以裂隙脉型矿化为主。     

柴北缘查查香卡铀-钍-铌-稀土矿床地质特征及矿床成因:一种与钠长岩相关的新矿化类型

青海查查香卡铀-钍-铌-稀土矿床位于柴达木盆地北缘的柴达木—阿尔金超高压变质杂岩带东端,是中国发现的首例与钠长细晶岩脉相关的铀-钍-铌-稀土多金属成矿系统。矿化主要分为两类:脉状矿化和微细浸染脉状矿化。脉状矿化即为钠长岩脉;微细浸染脉状矿化是以微细浸染细脉产于绿片岩围岩中的矿化类型。详细的矿物学工作研究表明查查香卡矿床可初步划分为岩浆、热液主成矿和成矿后3个阶段。岩浆阶段以发育"水滴状"铀-钍-铌矿物(晶质铀矿、铀钍矿、钍石、维铌钙矿等)包体为典型特征,产于最主要的造岩矿物钠长石中;热液主成矿阶段主要以稀土矿化为主,伴随铌和钍矿化作用,矿石矿物包括褐帘石、氟碳铈矿、钍石、含铌榍石(?)、锆石等,与磷灰石、方解石、绿泥石、石英等中低温脉石矿物普遍共生;成矿后阶段以广泛出现的方解石±石英网脉为特征。通过矿物学研究和主微量元素数据的综合分析,初步认为钠长岩脉为岩浆-热液成因,源于富含稀土和铌等成矿元素的富集地幔部分熔融岩浆的演化;岩浆成矿作用过程中可能经历了硅酸盐熔体与碳酸盐/磷酸盐熔/流体的分离作用,但本矿床更为重要的成矿元素富集机制为硅酸盐熔体与富氯岩浆热液流体的不混溶作用,后者引发本矿床大规模的稀土成矿作用,并活化和再富集了铌和钍。钠长岩脉特征的红色形貌特征可作为此类矿床一个重要的野外找矿特征,根据类似成矿系统的成矿模式,认为矿床深部及外围隐伏区仍有较大的成矿潜力。     

桂北宝坛锡多金属成矿区平英岩体晚期侵入岩的年代学、地球化学特征及其地质意义

桂北宝坛锡多金属成矿区内岩浆活动频繁,其中与锡多金属成矿作用有关的平英岩体由早晚两期侵入岩组成,且晚期侵入岩中常含有较多的电英岩包体。岩石学、锆石U-Pb年代学和地球化学研究表明：平英岩体晚期侵入岩主要岩性是（中）细粒斑状黑云母（二长-）碱长花岗岩;晚期侵入岩的形成年龄为（769.2±2.5）Ma,而电英岩包体的形成年龄为（795.1±3.1）Ma;平英岩体总体以富含大离子亲石元素（LILE,包括Rb、Th和U等）、贫高场强元素（HFSE,包括Nb和Ti等）为特征,其早期侵入岩属于高钾钙碱性强过铝质S型花岗岩,具有明显的Th-U元素"U"型峰值以及Ti元素"V"型谷值,晚期侵入岩属于钾玄岩系列岩石,具有U元素"V"型尖峰值以及La-Nd和Eu-Ti元素"U"型谷值,二者在地球化学特征上存在较大的差异。结合岩浆源区性质的研究结果,早期侵入岩属于造山后花岗岩类,可能是源自泥质岩类部分熔融形成的岩浆,再经历高程度分离结晶作用形成的产物;而晚期侵入岩属于非造山花岗岩类,可能是源自泥质岩和砂屑岩类部分熔融形成的岩浆与幔源岩浆发生了不同程度的混合形成的产物。结合电英岩包体和寨滚锡多金属矿床中岩浆热液成矿阶段形成的电英岩脉在成因上存在亲缘关系,且其形成年龄与田棚岩体的形成年龄基本一致的特征,推测电英岩包体应为晚期侵入岩侵位过程中捕获早期侵入岩（田棚岩体）侵位过程中形成的岩浆热液型电英岩脉而形成的包体,其形成年龄可能代表了本区电英岩成矿阶段的成矿年龄。     

阿尔泰萨热阔布金矿床的自然铋及其与金矿化关系

萨热阔布金矿是阿尔泰山南缘金一多金属矿带中与断裂变质作用有关的石英脉一蚀变岩型金矿床。本文通过电子探针的研究,在该矿区发现较多的自然铋矿物,它与金矿化关系非常密切,产出于多金属硫化物阶段,与方铅矿、黄铜矿等共生。矿区蚀变岩和矿石的微量元素R型聚类分析表明,Bi与Au相关最密切,Au、Cu、Ag、Bi是主要的成矿元素组合。Bi异常可以作为金矿化的重要指示,自然铋矿物的出现可以作为含金石英脉富矿地段的重要标志。     

辽宁王家崴子金矿床矿石特征与金的赋存状态

王家崴子金矿主要的矿石类型为含金石英脉型.矿石中富含黄铁矿,作为主要的载金矿物,与金矿化具有密切的时空及成因联系,是金矿化的重要指示矿物.矿石呈不等粒粒状、交代溶蚀结构,块状、致密块状、细脉浸染状构造.金矿物以形态复杂的中、细粒状银金矿、金银矿为主,赋存形式有裂隙金、晶隙金、包裹体金.载金矿物有黄铁矿、方铅矿、闪锌矿、黄铜矿、石英等.综合分析认为,该矿床具有变质热液型金矿床的特点,多源性的中温-中低温热液为主要成矿因素.     

西藏甲玛铜多金属矿床金矿地质特征及成矿作用

甲玛铜多金属矿床按照赋矿岩石不同,共包含产于矽卡岩中的与铜共生的金矿(化)体、产于板岩-角岩中的脉状金矿(化)体、产于大理岩中的脉状金矿(化)体以及产于玢(斑)岩脉中的独立金矿(化)体4种金矿化类型。矽卡岩中的金矿化较强,全矿区金品位×厚度基本都大于1 m.g/t,存在多个富金块段;板岩中金矿化主要分布在矿区外围破碎细粒黄铁矿化硅化板岩中,角岩中金矿(化)体以富含雄黄、雌黄为特征;大理岩中金矿化较弱,矿(化)体通常呈透镜状产出;玢(斑)岩中金矿化主要产于岩脉中的石英脉内。矿石中金的赋存状态主要以独立矿物和类质同像形式存在。独立矿物形式的金以自然金、银金矿存在于铜矿物、石英、黄铁矿等载金矿物内;类质同像形式的金主要存在于以斑铜矿、黄铜矿为代表的铜矿物中。金矿物赋存状态以粒间金、包裹金为主,其次为连生金和裂隙金。笔者以甲玛铜多金属矿床金的地质特征、分布规律及赋存状态为研究基础,推测甲玛金成矿作用与幔源C-H-O流体有关,并初步建立了甲玛铜多金属矿床金成矿模型。此外,提出了运用模型开展区域及矿区下一步找矿工作的建议。     

湖北丹江口市陈家垭铁矿床地质特征及成矿模式探讨

陈家垭铁矿床位于东秦岭Au-Ag-Mo-Cu-Pb-Zn-Sb-非金属成矿带.含铁围岩变细碧玢岩、变角斑质凝灰岩是成矿的基础,矿化强度与离火山活动中心的远近成正比,区域变质作用是促使矿物改造,使含铁火山岩中铁矿重新组合成浸染状磁铁矿—赤铁矿,使其富集.     

铁矿物催化氧化技术在水处理中的应用

广泛存在于地下水中的各种有机污染物严重影响着水资源的安全利用,常见的水处理工艺对持久性有机污染物去除效果不够理想。近年来,天然含铁矿物作为催化剂,催化过氧化氢的化学治理方法对各种有机污染物去除效果显著。概述近年来主要含铁矿物、负载型矿物和纳米矿物材料催化过氧化氢在地下水有机污染去除中的应用,探讨了该领域的发展现状和存在问题,并对其应用前景进行展望。认为天然矿物材料具有成本低、在地壳中含量高、环境友好等特点,可用于多种有机污染物的去除与降解。但处理过程中,天然有机质的作用、纳米矿物材料的毒性和地球化学归宿问题应该做进一步研究。     

Magnetic, Geochemical and Mineralogical Charac teristics of Soils in Qiangtang Basin, Tibet, China: Implications for Prospective Oil and Gas Land

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Mineralogy and Mode of Occurrence of Gold, Silver and Bismuth of the Caijiaying Lead-Zine-Silver Deposit, Hebei Province

The deposit under study is a hydrothermal filling-metasomatic vein type lead-zinc-silver deposit, in whichgold and silver can be recovered as by-products. These metals mainly occur as microgranular native gold,electrum, stephanite, acanthite, pyraragyrite, freibergite, and native silver. Gold minerals tend to be associatedwith galenobismutite, native bismuth and unnamed Bi_2Te. They are either enclosed in pyrite, marmatite,iron-bearing sphalerite and galens or fill the microfissures of these minerals. Silver minerals usually occur incleavages or fissures of galena, marmatite and pyrite, but are not associated with gold and bismuth minerals.Gold and silver mineralizations occurred later than lead and zinc, while the silver mineralization was precededby that of gold.     

Evolution of the Acipayam (Denizli,Turkey) Rodingites

Numerous diabase and gabbro dikes intrude the Lycian peridotite thrust sheet of southwestern Turkey. Some of the dikes are rodingitized and the host harzburgite is serpentinized. The present study demonstrates that the major episodes of serpentinization (of harzburgite) and rodingitization (of dikes) predated the obduction of the Lycian peridotite thrust sheet. Hydrogrossular veins, which represent the major event of calcium metasomatism in the dikes, are locally fractured, fragmented, and offset. High-field-strength-element concentrations and Ta/Yb-Th/Yb ratios in the mafic rocks suggest that the dikes were originally emplaced in an island-arc environment; thus, they must have been transported to their current location.

Fluid-inclusion microthermometry obtained on primary fluid inclusions in hydrogrossulars indicates that the fluid involved in rodingitization and contemporaneous serpentinization was moderately saline (8 equiv. wt% NaCl) and within the range of 250°-450°C. The above salinity and temperature are consistent with microthermometric measurements obtained from rodingite minerals worldwide.

It is apparent from our study that rodingite geochemistry and mineralogy provide valuable information on the tectonic and metamorphic evolution of a region. Trace-element and REE geochemistry can define the tectonic setting of dikes, detailed mineralogy of the dikes and host serpentinite provides information on the relative timing of serpentinization and contemporaneous rodingitization, and fluid-inclusion microthermometry provides information on the temperature and composition of the Ca-rich metamorphic fluids.     

Subvolcanic gabbro–porphyrite and intrusive diorite,and sulfide mineralization of the Dzhusa volcanogenic massive sulfide deposit (Southern Urals)

Two sequentially formed groups of dikes in the gabbro–porphyrite complex have been distinguished, the ages of which are early Eifelian (early dikes) and early Givetian (late dikes). We have estimated the temperature impact of ore contact metamorphism, which is related to dikes of the Lower Carboniferous Magnitogorsk intrusive complex. A hidden zonality of microimpurities in the ore-forming minerals has been established for the first time by the LA-ICP-MS method. The ore formation age has been determined as early Eifelian–early Givetian.     

Controls of Acid-sensitive Minerals on Reservoir Sensitivity Testing: An Example from the Silurian Kepingtage Formation in Tazhong Area, Tarim Basin

The Silurian Kepingtage Formation in Tazhong area is regarded as an acid-sensitive hydrocarbon reservoir. However, formation mechanism of acid-sensitive of the reservoir cannot be interpreted by the existing acid-sensitive evaluation criterion based on damage rate. The contents of acid-sensitive minerals illustrated by bulk-rock XRD, scanning electron microscopy and clay mineral composition analysis exert the dominant control on acid-sensitive flow testing of the reservoir. The iron-bearing minerals (including pyrite cements and chlorite cements) mainly deteriorate reservoir quality, while the iron-free minerals (including calcite cements and dolomite cements) mainly improve permeability. The permeability variation of the tested samples is controlled by the relative content of two acid-sensitive minerals. On the basis of newly established sensitivity mechanism and its influence on permeability, the corresponding ion (Fe2+) stabilizer was added to the acidizing fluids during the acidification reconstruction, which inhibited the negative factors of acid-sensitive minerals and improved the target layer quality effectively.     

胶东北部碱性超基性脉岩地球化学特征及环境和成因探讨

胶东地区脉岩属碱性超基性岩系(Na₂O+K₂O=4.67%～5.43%;SiO₂=36.70%～39.99%),岩性为单一的橄榄辉石岩。从主量元素(包括CIPW标准矿物组成)和过渡元素组成来看,该岩系近似原始岩浆组成。电子探针结果显示:橄榄石为富镁质橄榄石(贵橄榄石)(Fo=71～90),单斜辉石为透辉石(次透辉石为主)。岩石富集大离子亲石元素(K、Rb、Sr、Th和Ba),但不具有高场强元素(Nb、Ta、Zr和Hf)的亏损,表明岩石形成于大陆板内环境,为地幔橄榄岩低度部分熔融(3.4%)的产物。同时,它具有大陆边缘弧的特性,暗示其为一种滞后型弧岩浆作用的产物。稀土元素特征显示,岩石强烈富集LREE,而相对亏损HREE,暗示了源区的富集特性。Eu/Eu^*=0.89～1.00,总体不表现明显的负Eu异常,暗示斜长石不是主要的分馏矿物相。结合板内碱性岩石的矿物结晶顺序认为,本区岩浆分馏以较弱的橄榄石分馏为主。     

黑龙江多宝山矿田争光金矿床类型、U-Pb年代学及古火山机构

争光金矿床(伴生锌)位于我国东北地区黑龙江省多宝山Cu-Au-Mo成矿带南东端,构造上处于古亚洲成矿构造域和滨太平洋成矿构造域的叠加部位。该金矿距北西向的多宝山铜金矿和铜山铜矿分别约为10km和5km,因此,深入研究其成矿时代、成因类型归属,理清与多宝山铜金矿-铜山铜矿的关系具有重要科学价值。争光金矿赋矿围岩为奥陶系多宝山组安山质火山岩地层,发育爆发相、溢流相、火山碎屑流相、火山沉积相等,且爆发相和喷溢相交替出现,具有喷发时期熔岩溢流与火山碎屑物的喷发交替进行或具多旋回火山活动的特征;根据火山集块岩、火山角砾岩、火山碎屑岩的空间展布及岩相变化特征,推测矿区内发育有古火山机构。受后期北西向构造影响,火山岩地层具北西向弱定向变形特征。含金脉系呈脉状、网脉状沿北西向、北东向及南北向构造产出;矿石矿物以黄铁矿、闪锌矿、黄铜矿、方铅矿为主,金以裂隙金、粒间金和包裹金的形式赋存于上述硫化物中,部分赋存在石英中。综合脉系特征、矿物组合、蚀变类型、闪锌矿Fe含量等,本文明确提出该矿床为中硫型浅成低温热液型金矿。对矿区内发育的成矿后闪长玢岩、花岗闪长斑岩及长石斑岩等脉岩的锆石U-Pb测年结果初步厘定争光金矿金成矿作用早于454Ma。综合判断争光金矿与多宝山含金斑岩铜矿、铜山铜矿同形成于480~454Ma受古亚洲洋俯冲作用控制的岛弧背景,构成完整的斑岩Cu-Au与中硫化型浅成低温热液Au成矿系统。     

人工回灌条件下的水岩作用室内实验研究

人工回灌过程中所发生的水岩作用是影响含水层地下水环境质量的重要因素。本次采用室内实验技术对人工回灌过程中的水文地球化学作用和各主要离子的来源进行了分析。结果表明：人工回灌过程中地下水中的Na＋不仅受混合作用的影响,还伴随有相应的阳离子交换反应和含Na矿物的溶解反应等,而且回灌过程对原始地下水中的Na＋、Cl-有稀释作用;K＋主要受到钾长石矿物溶解的影响;人工回灌过程中存在石膏、方解石等矿物组分溶解,并且介质中的含锰矿物和含铁矿物发生了溶解反应。     

Genesis of acid/basic rock associations: a case study The Kallithea intrusive complex,Samos, Greece

The Kallithea intrusive complex on Samos forms part of the Miocene granitoid province of the central Aegean. The complex consists of numerous composite dikes consisting of different I-type diorites, monzodiorites, (quartz) monzonites, granodiorites, and granites, as well as rare pegmatites. Within individual dikes the different rock types display various structural relationships to each other, most of which indicate that multiple intrusion was the main process responsible for the association of different rock types. Petrographical, geochemical, and Sr isotope data prove that at least some of the different magma pulses were genetically unrelated. For others, a comagmatic relationship cannot be excluded. The most spectacular feature of the composite dikes are net-veined parts in which spherical (pillow-like) to angular bodies of microdiorite are surrounded by a network of more felsic rocks of varying compositions (monzonites, granodiorites, and monzogranites). — For the microdiorite/monzogranite pairs, a formation by unmixing due to liquid immiscibility is suggested by the following facts: (a) the presence of monzogranite ocelli within the microdiorite bodies, (b) similar compositions of those minerals present in both the basic and felsic parts, (c) the enrichment of HFS elements in the basic parts and the depletion of these elements in the acid parts, (d) similar Sr isotope initial ratios. Such an origin, however, is excluded for the other net-veined parts having felsic veins of either monzonitic or granodioritic compositions. In these pairs, the HFS elements are enriched in the acid parts, common minerals may have different compositions, and Sr isotope initial ratios are different. These net-veined parts can only be explained by the model of multiple injections whereby a felsic melt intruded into a basic magma.