冀北张家口地区汉诺坝玄武岩中麻粒岩捕虏体的硫化物相

捕虏体麻粒岩是了解下地壳形成和演化的重要样品.汉诺坝新生代玄武岩中的二辉麻粒岩捕虏体样品中富含各种硫化物相,主要类型有:①孤立产出的球状出溶硫化物;②矿物颗粒之间或颗粒内的粗晶硫化物;③次生硫化物包裹体群;④裂隙充填硫化物.电子探针分析表明,硫化物的矿物成分均为贫镍磁黄铁矿,(Ni Co Cu)/Fe(原子比)远小于0.2;(Fe Cu Co Ni)/S(原子比)比地幔岩的磁黄铁矿小,多小于0.875,反映了一种S过饱和环境.各种产状的磁黄铁矿中Au、Ag都有一定的含量,其平均值分别为0.19%～0.22%(Au)、0.01%～0.02%(Ag),反映下地壳的麻粒岩化与金矿化的成因联系.磁黄铁矿的Ni、Co、Cu含量与S正相关,说明微量重金属元素与S具有同源的关系,由于地幔去气伴随S而进入下地壳.     

冀北张家口地区汉诺坝玄武岩中麻粒岩捕虏体的硫化物相

捕虏体麻粒岩是了解下地壳形成和演化的重要样品。汉诺坝新生代玄武岩中的二辉麻粒岩捕虏体样品中富含各种硫化物相,主要类型有:①孤立产出的球状出溶硫化物;②矿物颗粒之间或颗粒内的粗晶硫化物;③次生硫化物包裹体群;④裂隙充填硫化物。电子探针分析表明,硫化物的矿物成分均为贫镍磁黄铁矿,(Ni+Co+Cu)/Fe(原子比)远小于0.2;(Fe+Cu+Co+Ni)/S(原子比)比地幔岩的磁黄铁矿小,多小于0.875,反映了一种S过饱和环境。各种产状的磁黄铁矿中Au、Ag都有一定的含量,其平均值分别为0.19%～0.22%(Au)、0.01%～0.02%(Ag),反映下地壳的麻粒岩化与金矿化的成因联系。磁黄铁矿的Ni、Co、Cu含量与S正相关,说明微量重金属元素与S具有同源的关系,由于地幔去气伴随S而进入下地壳。     

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。     

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     

金川超大型铜镍矿床钴的赋存状态与富集过程研究

金川矿床位于龙首山隆起带东段，是中国最大的岩浆镍钴（铂族元素）矿床。该矿床中最重要的金属硫化物组合是磁黄铁矿、镍黄铁矿和黄铜矿，仅局部含有微量的辉钴矿等独立钴矿物。全岩成矿元素分析显示：矿石中Co与S、Ni之间呈良好的正相关性，与As相关性较差，Co/Ni随硫化物含量的增加而降低。电子探针分析结果表明：镍黄铁矿中Co含量较高，其含量为0.32%～1.93%，平均为0.81%；磁黄铁矿和黄铜矿（方黄铜矿）中Co的含量较低，变化范围分别为0.02%～0.11%和0.01%～0.08%。元素面扫描结果表明：Co含量较高的部位与镍黄铁矿范围完全一致，说明Co主要赋存于镍黄铁矿中。金川矿床整体Co/Ni平均值为0.042，与全球典型橄榄岩相地幔Co/Ni值（0.055）相似，表明其岩浆源区主要为橄榄岩相。高程度的部分熔融可能是导致其母岩浆中Co绝对含量较高，但Co/Ni值相对较低的原因之一。硫化物熔离时，Co更倾向于进入硫化物；但相对于Ni，进入硫化物的Co较少，导致不同矿石类型之间S含量与Co/Ni值之间呈明显的负相关性。硫化物分离结晶作用进一步促使Co向镍黄铁矿中富集。     

烧锅营子金矿黄铁矿的化学成分标型特征

烧锅营子金矿床的黄铁矿形成于早、中、晚3期,是主要的矿石矿物和载金矿物,其中以中期黄铁矿为最主要的载金者.黄铁矿的化学成分为:TFe43.34%~45.52%,S46.58%~48.86%,与标准黄铁矿相比显示亏铁、亏硫特点.黄铁矿内含丰富的微量元素,有Au、Ag、As、Sb、Bi、Cu、Zn、Pb、Co、Ni、W、Mo、Se等.其中Au、Ag、Cu、Pb、Zn、Bi含量较高,而As、Sb低,Se极低.其Au/Ag(多大于0.5)、(Cu+Pb+Zn)/(Co+Ni+As)(4.26)、Co/Ni(>> 1)比值表明其属中温岩浆热液矿床.     

福建牛头山新近纪碱性玄武岩中地幔岩包体内硫化物研究

福建牛头山一带新近纪碱性玄武岩中含有尖晶石二辉橄榄岩包体。这些地幔岩包体内普遍存在有硫化物。硫化物按产状和成因分为两类:1)分布于寄主矿物内部,未与裂隙相连,是地幔岩浆作用的产物;2)分布于颗粒内或颗粒边部,在裂隙上或与裂隙相连,是地幔流体交代作用的产物。电子探针分析表明,15个硫化物测点中,除2个黄铜矿、1个硫铜铁矿外,其余为不同Ni/Fe(mol比)比值的铁镍硫化物:6个测点为富镍镍黄铁矿,其Ni/Fe=0.98～2.79,(Fe+Ni)/S=1.03～1.08;2个为针镍矿,其Ni/Fe=5.5,(Fe+Ni)/S=1.01;4个测点为富镍磁黄铁矿,其Ni/Fe=0.29～0.49,(Fe+Ni)/S=0.79～0.94。4粒单一硫化物矿物的成份是不均一的,多数表现为自中心到边部Ni含量和Ni/Fe值呈增加趋势,而Fe和Cu含量呈减少趋势。本研究还发现单一硫化物中由中心到边部金与镍大致有相同的变化趋势。     

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。     

某贫镍矿石工艺矿物学研究

中国西部某大型镍矿具有极大的资源战略地位，本文采用化学分析方法和显微镜对矿石进行了研究，查明了矿石的物质成份、结构构造，并分析了其对选矿工艺的影响。结果表明：可回收的主要元素为Ni,Cu、Co、Au及Ag可综合回收利用，大部分镍黄铁矿易于离解，少部分离解难度较大，磁黄铁矿、褐铁矿、脉石矿物中的Ni回收难度较大，黄铜矿中的Cu易于回收，镍黄铁矿、磁黄铁矿及褐铁矿中的铜回收难度较大，应深入进行选矿工艺研究。     

粤北大宝山铜多金属矿区黄铁矿与磁黄铁矿EPMA和LA-ICP-MS原位微区组分特征及其对矿床成因机制约束

粤北大宝山铜多金属矿床一直存在燕山期岩浆热液成因和海西期火山喷流成因之争,争议的焦点在于块状、似层状硫化物矿体的成因。本文在全面开展矿区地质调查和钻探查证的基础上,对块状、似层状和脉状硫化物矿石中的黄铁矿和磁黄铁矿开展EPMA和LA-ICP-MS原位分析。测试结果表明,不同产状黄铁矿的平均分子式相似,分别为FeS_(1.98)、FeS_(1.99)和FeS_(1.98),似层状和脉状硫化物中磁黄铁矿的平均化学式为Fe_(0.886)S和Fe_(0.874)S,属形成温度相对较低单斜磁黄铁矿。与花岗岩岩浆热液标型黄铁矿相比,不同产状的黄铁矿和磁黄铁矿中Co、Ni、Mn、Se和Ge等元素以类质同象形式赋存,它们含量较低但稳定,Cu、Pb、Zn、Ag、Bi和Tl及Ga主要以微细矿物子晶形式存在,其含量丰富,但变化明显。从块状、似层状到脉状硫化物矿体,黄铁矿和磁黄铁矿中Co、Zn和Se的含量及Co/Ni值降低,而Cu、Pb、Ag、Bi等元素的含量明显升高。结合矿区次英安斑岩的产状和含矿性特征表明,大宝山矿床块状、似层状和脉状硫化物矿体都是次英安斑岩深部岩浆房产出的含矿流体在不同赋矿环境中的产物。     

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     

A catastrophic rockslide-debris flow in Wulong, Chongqing, China in 2009: background, characterization, and causes

On June 5, 2009, a catastrophic rockslide-debris flow occurred at the crest of the Jiweishan Mountain in Wulong, Chongqing, China. Approximately five million cubic meters of limestone blocks slid along a weak interlayer of bituminous and carbonaceous shale. The source mass descended from the upper part of the slope rapidly, crossing a 200-m wide and 50-m deep creek in front of it. Blocked by the opposite steep creek wall, the sliding mass changed its direction and traveled a further 2.2 km along the creek in debris-flow mode, finally forming a large accumulation zone with an average depth of 30 m. This is one of the most catastrophic rockslide events in recent years in China. It buried 12 houses and the entrance of an iron mining tunnel where some 27 miners were working inside. Ten people died, 64 missing, and eight wounded. Immediately after this disaster happened, the government organized an expert team to assist the rescue work. As one of the geological experts, the author did a lot of field investigations and collected first-hand information. Multi-methods including the remote sensing, 3D laser scanning, geophysical exploration, and numerical modeling were used for analyzing the characteristics and the triggering mechanism of the Wulong rockslide. The preliminary investigation results reveal that this rockslide with poor geological conditions was mainly induced by the gravitation and the karst effect and also affected by the previous mining activities. The research in this paper is meaningful and useful for further research on such kind of rockslides that are geologically similar to the Wulong rockslide.     

Shock-induced amorphous textures in plagioclase,Manicouagan, Quebec,Canada

The textural relationships and structural states of optically isotropic labradorite from the Manicouagan, Quebec, impact structure have been examined by light (optical) and transmission electron (TEM) microscopy. Two distinct diaplectic glasses have been recognized based on their contrasting morphology, timing and the inferred modes of formation. The earliest isotropic bands and grain-scale isotropism (maskelynite) optically exhibit a gradational,in situ transformation from crystalline plagioclase with preservation of relict textures (twins, grain boundaries). The same transformation from crystalline to amorphous structure is observed in TEM to occur heterogeneously at scales on the order of the unit cell. The progressive transformation of optical properties reflects an increase in the volume fraction and eventual coalescence of these amorphous units. This maskelynite-type diaplectic glass is interpreted to form in the solid-state directly from crystalline material during the compressional phase of the shock wave. The other isotropic material occurs in spatially discrete tensiongashes and planar deformation features (PDFs) that overprint the maskelynite-type glass. This second type of diaplectic glass (PDF-type) is developed homogeneously within a given glass band and exhibits sharp crystal-glass boundaries, in contrast to the gradational boundaries of the maskelynite-type glass. PDF-type glass is interpreted to form by melting in tensional release zones during passage of the rarefaction wave. These observations emphasize the ability of naturally shocked rocks to preserve subtle evidence of variations in the shock process from highly transient events.     

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.     

Analysis of F, Al, Mn, Zn, Fe, Cu, Ca and Mg concentrations in brick teas from main producing areas in China

Brick-tea-type fluorosis is a peculiar endemic disease in China, which had been discovered in minority areas of western China since 1980, and distributed mainly in Tibet, Inner Mongolia, Gansu, Xinjiang, Qinghai and parts of Sichuan Province. The prevalence rate of fluorosis in Tibetan and Mongolian nationality people was higher. Epidemiological investigation showed that fluorosis morbidity and degrees were different in different brick-tea drinking areas, and it was probably caused by drinking various kinds of brick tea from different regions. Therefore, we collected 33 samples of brick tea from six provinces where minority nationalities were accustomed to drinking a large quantity of brick tea. F concentrations were determined by the combustion hydrolysis-ion selective electrode method. The results showed that among the brick teas, the F concentrations ranged from the minimum 74.1 mg/kg in Yunnan Province to the maximum 991.2 mg/kg in Sichuan Province. Besides, there was a great difference among the various kinds of brick tea, and F concentrations decreased in the order of Kang brick tea, Green brick tea, Black brick tea, Mi brick tea, Fu brick tea, Chitsu ping tea, Puerh tea, and Tuo tea. The average F concentration in brick teas was 431.92 mg/kg.     

Neutron-capture elements in halo, thick-disk, and thin-disk stars. Strontium, yttrium, zirconium, cerium

We derived Sr, Y, Zr, and Ce abundances for a sample of 74 cool dwarfs and subgiants with iron abundances, [Fe/H], between 0.25 and ?2.43. These estimates were obtained using synthetic spectra, assuming local thermodynamic equilibrium (LTE) for Y, Zr, and Ce, allowing for non-LTE conditions for Sr. We used high-resolution (λ/Δλ?40 000 and 60 000) spectra with signal-to-noise ratios between 50 and 200. We find that the Zr/Y, Sr/Y, and Sr/Zr ratios for the halo stars are the same in a wide metallicity range (?2.43 ≤ [Fe/H] ≤ ?0.90), within the errors, indicating a common origin for these elements at the epoch of halo formation. The Zr/Y ratios for thick-disk stars quickly decrease with increasing Ba abundance, indicating a lower rate of production of Zr compared to Y during active thick-disk formation. The thick-disk and halo stars display an increase in the [Zr/Ba] ratio with decreasing Ba abundance and a correlation of the Zr and Eu overabundances relative to Ba. The evolutionary behavior of the abundance ratios found for the thick-disk and halo stars does not agree with current models for the Galaxy’s chemical evolution. The abundance ratios of Y and Zr to Fe and Ba for thin-disk stars, as well as the abundance ratios within each group, are, on average, solar, though we note a slight decrease of Zr/Ba and Zr/Y with increasing Ba abundance. These results provide evidence for a dominance of asymptotic-giant-branch stars in the enrichment of the interstellar medium in heavy elements during the thin-disk epoch, in agreement with the predictions of the nucleosynthesis theory for the main s-process component.     

Arsenic in streams,stream sediments,and ground water,fairbanks area,alaska

Arsenic concentrations of less than 5 ppb to as large as 1,260 ppb in stream waters and from 5 ppm to 4,000 ppm in stream sediments were found in the Pedro Dome-Cleary Summit area, Alaska. Waters from three of 20 wells sampled had arsenic concentrations exceeding the U.S. Public Health Service recommended limit of 50 ppb. The high arsenic levels are a consequence of arsenic enrichment in the rocks of the area. Placer and lode-gold mining may increase the arsenic content of the waters by exposing arsenic-containing rocks to surface waters and by increasing the load of arsenic-rich sediments in the streams. Finding these disturbingly large concentrations of arsenic in the waters of the Fairbanks area was the major result of this work, inasmuch as a subsequent study (to be published) revealed arsenic concentrations as large as 10 ppm in domestic wells and prompted an extensive study by Federal and State agencies of the health hazard posed by these arsenic-rich waters.     

湖北宜昌王家湾五峰组顶部Chondrites的发现及其环境意义

本文报道了湖北宜昌王家湾剖面五峰组笔石页岩段观音桥层发现的遗迹化石Chondrites的分布及其生态特点。结合生物相和同期上扬子海盆相对海平面的变化,分析了盆地水体底域在缺氧一富氧转折时期的古氧相变化特征：指出五峰组笔石页岩段上部地层沉积底域为典型的缺氧环境,在其与上覆观音桥段之间的沉积转换面附近发生了从无氧到有氧的转变,观音桥段中Hirnantia动物群繁盛于富氧的海底环境。     

Flood anticipation,reality, and uncertainty,the 2019 flood in Khuzestan,Iran

Natural Hazards - Despite the application of various methods to calculate uncertainty in flood vulnerability assessments, the challenge of uncertainty remains. The main purpose of this study was to...     

丘北普者黑岩溶地貌景观特征

通过介绍普者黑地区的岩溶地貌特征,借鉴石林和桂林的研究模式,对普者黑的岩溶地貌形成机理进行了深入研究,并针对普者黑独特的亚热带高原岩溶地貌的特征,阐述了其研究的科学价值。