初论雪峰山地区基性-超基性岩镍钴铜金矿找矿方向

近年来,雪峰山地区的基性-超基性岩矿床找矿工作取得了一定的进展。为了及时总结成矿规律,指导进一步的找矿工作,本文在大量野外调研的基础上,系统总结了该地区基性-超基性岩岩体的地质特征、已有找矿进展的长界镍矿和字溪金矿地质特征及已发现的镍钴铜金等矿化特征,并与国内外同类型矿床的成矿特征进行了比较,最后提出了如下认识:雪峰山地区具备找寻基性-超基性岩矿床潜力,目标矿种主要为镍、钴、铜及金矿,主要矿床类型为岩浆硫化物型镍钴铜矿及蚀变热液型金矿。前者目标地质体以通道-洪江-中方-古丈一带新元古代基性-超基性岩群/带最为有利,后者则以隘口岩群及艾头坪-大洪山岩群的大洪山段最为有利。     

桂东龙水金矿床地质特征及成因

龙水金矿是赋存于大宁花岗闪长岩体外接触带的破碎蚀变岩型金矿。从矿床地质、矿石物质成分及金的赋存状态、围岩蚀变、矿物流体包裹体、稳定同位素等不同方面阐明金矿床的地球化学特征,认为龙水金矿的形成是在变质热液成矿的基础上叠加后期岩浆热液成矿作用的复合成因金矿床。矿区外围还具有找矿远景。     

陕西煎茶岭镍矿床控矿因素及找矿标志

陕西略阳煎茶岭镍矿位于勉略结合带上,成矿区带属勉略华力西—印支蛇绿杂岩Mn-P-Cr-Ni-Au成矿亚带之略阳金家河-汉中天台山锰磷镍远景区内;矿床成因为岩浆熔离-热液改造型,赋矿岩体为元古代(Pt3)变质(蚀变)超基性岩,早期含镍超基性主岩体是成矿基本场所,后期中酸性岩对超基性主岩体进行改造,总体上为低品位硫化镍大型矿床,伴生低品位Co。通过对矿床大地构造位置、岩体特征、矿体特征等分析,总结了矿床控矿因素及找矿标志特征,认为该矿床成矿作用主要受镁质超基性岩、构造破碎带控制,中酸性侵入岩提供了镁质超基性岩再造成矿所需的热动力。     

吉林省红旗岭矿区3号含矿岩体同位素年龄研究

通过对红旗岭矿区3号含矿岩体同位素年龄研究,该岩体锆石U-Pb年龄为(207±3)Ma,黑云母Ar-Ar年龄为(212.5±2.5)Ma,矿石Re-Os等时线年龄为(234±28)Ma,表明该含矿岩体形成于三叠纪晚期。该年龄和近年来对含矿基性-超基性岩体同位素年龄测定结果基本一致(205~230 Ma),说明它们均为三叠纪晚期岩浆作用的产物。根据岩体围岩年龄(Rb-Sr全岩等时线年龄(524±16)Ma和(357±23)Ma),认为该岩体成岩成矿主要形成于印支中晚期,是同一期构造岩浆活动的产物,岩浆及成矿物质来源具有同源性,从而形成了具有相同成因的矿床类型。     

云南墨江金矿床的同位素地球化学及成因探讨

墨江金矿的同位素地球化学特征,成矿元素组合和包裹体成分表明：成矿物质主要来源于金厂蚀变超基性岩体,成矿热液是深源流体,岩浆水和大气降水混合的产物。成矿期深部富矿化剂流体沿断裂上升并与地下水混合,从侵入体及围岩中淋滤出了成矿物质。在迁移过程中,随着地球化学条件的改变,金在有利部位沉淀富集形成矿床。墨江金矿床属混合热液改造型矿床。     

金平棉花地钛磁铁矿大坡矿段成矿条件

基性-超基性岩浆杂岩是区内钛磁铁矿床的母岩体,矿体产于岩体中及边部,凤港组角闪斜长片麻岩和黑云斜长片麻岩是有利围岩,矿床成因属岩浆晚期结晶分异-变质矿床。预测本区有中-大型铁矿规模的找矿前景。     

冀东金厂峪特大型金矿床的地质地球化学特征和矿床成因

金厂峪金矿产于八道河群王厂组，矿体受刘村寨－双沟峪复式向斜控制，成矿与中生代构造作用及岩浆活动有密切关系矿床的形成经历了复式向斜构造的形成，与岩浆活动有关的成矿热液沿构造薄弱带运移；热液蚀变及矿质沉淀。硫，氧，碳，铅同位素数据表明成矿物质来源于深部，与矿床围岩具有不同的属性。     

西秦岭李坝式金矿床地球化学特征及找矿方向研究

李坝式金矿床是位于西秦岭礼岷金成矿带中川印支-燕山早期岩体外接触带微细粒浸染型金矿类型,其成矿与岩体、构造等关系密切,含矿围岩为成矿提供了矿质来源,金矿(化)体与围岩具有相似的稀土元素地球化学特征,中川岩体为成矿提供了热动力.氢氧同住素研究表明,由岩浆水、地层水、大气降水等共同组成了成矿热液,热液沿构造带上升的过程中萃取了容矿围岩中的成矿物质.在地壳浅部由于物化条件的改变在容矿构造中富集成矿,形成金矿体,并形成了特定的围岩蚀变,因而属地下热卤水溶滤型浅成中低温充填-交代型金矿床.在此基础上建立了西秦岭礼岷金成矿带岩体(岩脉)、地化异常、构造、蚀变四位一体的综合找矿模式,热接触变质作用形成的黑云母带(Ⅱ带)是区域找矿的有利部位.     

镇沅金矿田围岩蚀变及成矿系列

镇沅金矿田是云南省唯一超大型金矿。多期次成矿，矿床类型、蚀变种类复杂多样。形成时间基本同步，空间整体配置明显分带。伴随每一成矿阶段有相应的围岩蚀变，自然金、载金黄铁矿与近矿蚀变矿物在同一溶液中同时沉积。随着容矿主岩从内向外，从超基性岩、基性岩－云煌岩－中酸性斑岩、长英质岩渐次变化，表征矿床类型的主要围岩蚀变变化系列为：黄铁矿－碳酸盐化→黄铁矿－碳酸盐－绢云母化→硅化和黄铁－绢英岩蚀变，成因上具有密切的内在联系。特别是花岗岩类斑岩岩浆在侵位过程中，通过不断的液态不混溶或液态分离演变，相继形成斑岩矿浆型、岩浆后期热液成因的斑岩型及以浊积岩为主岩的岩浆后期至岩浆期后热液型金矿体（床）和相应的热液蚀变，构成较复杂的热液蚀变及成矿系列。矿田内与花岗岩类斑岩有关的矿床的勘查程度尚浅，有扩大规模的较大远景。     

墨江金矿床的成矿物质来源探讨

以往,对墨江金矿床的成矿物质来源存在着三种不同的看法(观点):(1)成矿物质来源于金厂组(下-中志留统)浅变质岩系;(2)成矿物质来源于距今2700Ma的古老基底;(3)成矿物质主要来源于金厂蚀变超基性岩体。本文从矿床的同位素组成、微量元素、包体成分等方面,论证墨江金矿床的成矿物质主要来源于金厂蚀变超基性岩体,金厂组变质岩系也可能提供少量的成矿物质。矿床属于浅成中-低温热液成因。含矿热液是有大量大气降水加入的Ca~(++)+Mg~(++)/SO_4型流体。超基性岩体滑石化、蛇纹石化、碳酸盐化过程中,在碱性、相对还原的介质条件下,金等成矿物质主要以硫络合物的方式进入成矿溶液,并在fO_2、fS_2、pH,Eh、T、P等物理化学参数发生变化的条件下沉淀。     

Wavelength-dispersive X-ray fluorescence spectrometric determination of Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites

Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.     

高压微波消解法测定醋酸纤维过滤器采集的微尘粒子中的砷镉钴铬铜铁锰镍铅钒锌

最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提     

Isotopic systematics of He,Ar, S,Cu, Ni,Re, Os,Pb, U,Sm, Nd,Rb, Sr,Lu, and Hf in the rocks and ores of the Norilsk deposits

This paper reports the first results of a study of 11 isotope systems (³He/⁴He, ⁴⁰Ar/³⁶Ar, ³⁴S/³²S, ⁶⁵Cu/⁶³Cu, ⁶²Ni/⁶⁰Ni, ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ^206–208Pb/²⁰⁴Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.     

硅酸盐中铁、锰、钛、钙、钾、磷、硅、铝、镁、钠、锶、铷、钡的X-射线荧光光谱定量测定

本文介绍样品经四硼酸锂熔融制成玻璃小饼。采用Lachance模式和理论a系数来校正元素间的效应,由3080E型X-射线荧光谱仪和DF-350B数据处理系统完成硅酸盐中十三个项目的测定。     

硅酸盐类样品中硅、铁、铝、钛、锰、钙、镁、钾、钠和磷的x射线荧光光谱测定

本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。     

Viscous, cohesive, non-Newtonian, depositing, radial slurry flow

Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance.     

Mountains,nations, parks,and conservation

Between 1985 and 1991, two new mountain protected areas (MTNPA) covering more than 35,000 km² and based on participatory management models — the Makalu-Barun National Park and Conservation Area, Nepal, and Qomolangma Nature Preserve, Tibet Autonomous Region — were successfully established through the collaborative efforts of Woodlands Mountain Institute and conservationists in China and Nepal. Characteristics common to both projects include the importance of establishing (1) effective rationales, (2) local support constituencies, (3) a senior advisory group, (4) a task force, (5) linkages between conservation and development, and (6) fund raising mechanisms. The lessons derived from the experiences of Woodlands Mountain Institute are of significant value to others in preserving MTNPA. Increased collaboration and communication between all interested in conservation, however, will remain a critical component for expanding mountain protected area coverage to throughout the world.     

岩石密度和超高压岩石折返速率

在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。     

Regional distribution of Al,B, Ba,Ca, K,La, Mg,Mn, Na,P, Rb,Si, Sr,Th, U and Y in terrestrial moss within a 188,000 km2 area of the central Barents region: influence of geology,seaspray and human activity

Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km² area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).