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1.
C. Reimann P. Englmaier B. Flem L. Gough P. Lamothe Ø. Nordgulen D. Smith 《Applied Geochemistry》2009
Forty soil O- and C-horizon samples were collected along a south-to-north transect extending inland for approximately 200 km from the southern tip of Norway. The elements As, Au, Bi, Cd, Cu, Ga, Ge, Hf, Hg, In, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, V, W, Zn and Zr all show a distinct decrease in concentration in soil O-horizons with increasing distance from the coast. The elements showing the strongest coastal enrichment, some by more than an order of magnitude compared to inland samples, are Au, Bi, As, Pb, Sb and Sn. Furthermore, the elements Cd (median O-/median C-horizon = 31), C, Sb, Ag, K, S, Ge (10), Hg, Pb, As, Bi, Sr (5), Se, Au, Ba, Na, Zn, P, Cu and Sn (2) are all strongly enriched in the O-horizon when compared to the underlying C-horizon. Lead isotope ratios, however, do not show any gradient with distance from the coast (declining Pb concentration). Along a 50 km topographically steep east–west transect in the centre of the survey area, far from the coast but crossing several vegetation zones, similar element enrichment patterns and concentration gradients can be observed in the O-horizon. Lead isotope ratios in the O-horizon correlate along both transects with pH and the C/N-ratio, both proxies for the quality of the organic material. Natural conditions in southern Norway, related to climate and vegetation, rather than long range atmospheric transport of air pollutants (LRT), cause the observed features. 相似文献
2.
Bo Peng Xiaoya Tang Changxun Yu Changyin Tan Chunyan Yin Guang Yang Qian Liu Kesu Yang Xianglin Tu 《Environmental Earth Sciences》2011,64(5):1455-1473
This paper reports a geochemical study of trace metals and Pb isotopes of sediments from the lowermost Xiangjiang River, Hunan
province (P. R. China). Trace metals Ba, Bi, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Cd, Sn, Sb, Pb, Tl, Th, U, Zr, Hf, Nb and
Ta were analyzed using ICP-MS, and Pb isotopes of the bulk sediments were measured by MC-ICP-MS. The results show that trace
metals Cd, Bi, Sn, Sc, Cr, Mn, Co, Ni, Cu, Zn, Sb, Pb and Tl are enriched in the sediments. Among these metals, Cd, Bi and
Sn are extremely highly enriched (EF values >40), metals Zn, Sn, Sb and Pb significantly highly (5 < EF < 20), and metals
Sc, Cr, Mn, Co, Ni, Cu and Tl moderately highly (2 < EF < 5) enriched in the river sediments. All these metals, however, are
moderately enriched in the lake sediments. Geochemical results of trace metals Th, Sc, Co, Cr, Zr, Hf and La, and Pb isotopes
suggest that metals in the river sediments are of multi-sources, including both natural and anthropogenic sources. Metals
of the natural sources might be contributed mostly from weathering of the Indosinian granites (GR) and Palaeozoic sandstones
(PL), and metals of anthropogenic sources were contributed from Pb–Zn ore deposits distributed in upper river areas. Metals
in the lake sediments consist of the anthropogenic proportions, which were contributed from automobile exhausts and coal dusts.
Thus, heavy-metal contamination for the river sediments is attributed to the exploitation and utilization (e.g., mining, smelting,
and refining) of Pb–Zn ore mineral resources in the upper river areas, and this for the lake sediments was caused by automobile
exhausts and coal combustion. Metals Bi, Cd, Pb, Sn and Sb have anthropogenic proportion of higher than 90%, with natural
contribution less than 10%. Metals Mn and Zn consist of anthropogenic proportion of 60–85%, with natural proportion higher
than 15%. Metals Sc, Cr, Co, Cu, Tl, Th, U and Ta have anthropogenic proportion of 30–70%, with natural contribution higher
than 30%. Metals Ba, V and Mo might be contributed mostly from natural process. 相似文献
3.
Concentrations of platinum group elements (PGE), Ag, As, Au, Bi, Cd, Co, Mo, Pb, Re, Sb, Se, Sn, Te, and Zn, have been determined
in base metal sulfide (BMS) minerals from the western branch (402 Trough orebodies) of the Creighton Ni–Cu–PGE sulfide deposit,
Sudbury, Canada. The sulfide assemblage is dominated by pyrrhotite, with minor pentlandite, chalcopyrite, and pyrite, and
they represent monosulfide solid solution (MSS) cumulates. The aim of this study was to establish the distribution of the
PGE among the BMS and platinum group minerals (PGM) in order to understand better the petrogenesis of the deposit. Mass balance
calculations show that the BMS host all of the Co and Se, a significant proportion (40–90%) of Os, Pd, Ru, Cd, Sn, and Zn,
but very little (<35%) of the Ag, Au, Bi, Ir, Mo, Pb, Pt, Rh, Re, Sb, and Te. Osmium and Ru are concentrated in equal proportions
in pyrrhotite, pentlandite, and pyrite. Cobalt and Pd (∼1 ppm) are concentrated in pentlandite. Silver, Cd, Sn, Zn, and in
rare cases Au and Te, are concentrated in chalcopyrite. Selenium is present in equal proportions in all three BMS. Iridium,
Rh, and Pt are present in euhedrally zoned PGE sulfarsenides, which comprise irarsite (IrAsS), hollingworthite (RhAsS), PGE-Ni-rich
cobaltite (CoAsS), and subordinate sperrylite (PtAs2), all of which are hosted predominantly in pyrrhotite and pentlandite. Silver, Au, Bi, Mo, Pb, Re, Sb, and Te are found predominantly
in discrete accessory minerals such as electrum (Au–Ag alloy), hessite (Ag2Te), michenerite (PdBiTe), and rhenium sulfides. The enrichment of Os, Ru, Ni, and Co in pyrrhotite, pentlandite, and pyrite
and Ag, Au, Cd, Sn, Te, and Zn in chalcopyrite can be explained by fractional crystallization of MSS from a sulfide liquid
followed by exsolution of the sulfides. The early crystallization of the PGE sulfarsenides from the sulfide melt depleted
the MSS in Ir and Rh. The bulk of Pd in pentlandite cannot be explained by sulfide fractionation alone because Pd should have
partitioned into the residual Cu-rich liquid and be in chalcopyrite or in PGM around chalcopyrite. The variation of Pd among
different pentlandite textures provides evidence that Pd diffuses into pentlandite during its exsolution from MSS. The source
of Pd was from the small quantity of Pd that partitioned originally into the MSS and a larger quantity of Pd in the nearby
Cu-rich portion (intermediate solid solution and/or Pd-bearing PGM). The source of Pd became depleted during the diffusion
process, thus later-forming pentlandite (rims of coarse-granular, veinlets, and exsolution flames) contains less Pd than early-forming
pentlandite (cores of coarse-granular). 相似文献
4.
西藏柯月Pb-Zn-Sb-Ag多金属矿床位于雅鲁藏布江缝合带（IYS）与藏南拆离系（STDS）之间的北喜马拉雅成矿带。该矿床经详查验证,4 300 m以浅的矿体赋存于日当组钙质板岩夹薄层泥晶灰岩中,严格受北东向断裂控制,但深部延伸不明。本文通过该矿床I号矿体原生晕地球化学特征分析,对此问题进行初步探讨。研究表明,前缘晕元素为Hg、As、Tl,近矿晕元素为Pb、Zn、Sb、Ag、Au、Cd、Cu、Mn,尾晕元素为Sn、In、Bi;采用改良的格里戈良分带指数法计算分带序列为In-Mn-As-Cu-Zn-Cd-Bi-Pb-Sn-Hg-Tl-Ag-Au-Sb,重心法计算分带序列为In-Mn-As-Cu-Cd-Zn-Hg-Bi-Sn-Pb-Ag-Sb-Tl-Au;同时,讨论原生晕地球化学参数变化规律,并以各元素的几何平均值累乘比建立矿体的剥蚀参数模型及矿体原生晕叠加理想模型。综合以上分析,推测矿床有多次成矿作用叠加,上部存在剥蚀至尾部的矿体,而深部可能有矿体延伸。 相似文献
5.
Hideo Higuchi John W Morgan R Ganapathy Edward Anders 《Geochimica et cosmochimica acta》1976,40(12):1563-1571
Four ureilites (Dyalpur, Goalpara, Haverö, and Novo Urei) were analyzed by radiochemical neutron activation analysis for Ag, Au, Bi, Br, Cd, Cs, Ge, In, Ir, Ni, Rb, Re, Sb, Se, Te, Tl, and U. An attempt has been made to resolve the data into contributions from the parent ultramafic rock and the injected, carbon- and gas-rich vein material. Interelement correlations, supported by analyses of separated vein material (WANKE et al, 1972), suggest that the vein material is enriched about 10-fold in refractory Ir and Re over moderately volatile Ni and Au, and is low in volatiles except Ge, C, and noble gases. It appears to be a refractory-rich nebular condensate that precipitated carbon by surface catalytic reactions at ˜500K and trapped noble gases but few other volatiles. The closest known analogue is a Cr- and C-rich fraction from the Allende meteorite, highly enriched in heavy noble gases and noble metals. By analogy with Allende, the gas-bearing phase in ureilites may have been an Fe, Cr-sulfide.
The ultramafic rock contains siderophiles and chalcophiles (Ni, Au, Ge, S, Se) at ˜0.05 of Cl chondrite level, and highly volatile elements (Rb, Cs, Bi, Tl, Br, Te, In, Cd) at ˜0.01 Cl level. It probably represents the residue from partial melting of a C3V-like chondrite body, under conditions where phase separation was incomplete so that some liquid was retained. The vein material was injected into this rock at some later time. 相似文献
6.
黑色页岩与土壤重金属污染 总被引：6，自引：1，他引：5
本文利用ICP—MS等技术分析了湘中地区黑色页岩及其相应土壤的重金属含量,在对分析结果进行统计分析的基础上,探讨了黑色页岩与土壤重金属污染的关系。研究表明,黑色页岩是富集多种重金属元素的特殊岩石。以黑色页岩岩系为母岩的土壤,不仅明显富集Cu、Cd、Cr、Co、Pb、Zn、Mo、Ni、V、U、Sn、Sb、T1、Th等多种重金属元素,而且受到Mo、Sb、Cd、U、Tl、Cu、V、Sn、Th等重金属的污染,其中以Mo、Cd、Sb、U、Tl等的污染尤为严重。黑色页岩土壤重金属污染在一些地方已产生明显的负面环境效应,值得关注。 相似文献
7.
Accumulation and sources of heavy metals in urban topsoils: a case study from the city of Xuzhou, China 总被引：8，自引：0，他引：8
The knowledge of the variability, the anthropogenic versus natural origin and corresponding environmental risk for potentially harmful elements in urban topsoils is of importance to assess human impact. The aims of the present study were: (1) to assess the distribution of heavy metals (Sn, Li, Ga, Ba, Fe, Mn, Co, Be, Ti, Al, Hg, Cr, Sb, As, Bi, Pd, Pt, Au, Ni, Cd, Zn, Cu, Pb, Se, Mo, Sc and Ag) in urban environment; (2) to discriminate natural and anthropogenic contributions; and (3) to identify possible sources of pollution. Multivariate statistic approaches (principal component analysis and cluster analysis) were adopted for data treatment, allowing the identification of three main factors controlling the heavy metal variability in Xuzhou urban topsoils. Results demonstrate that Hg, Cr, Sb, As, Bi, Pd, Pt, Au, Ni, Cd, Br, Zn, Cu, S, Pb, Se, Mo, Sc and Ag could be inferred to be tracers of anthropogenic pollution, whereas Al, Ti, Ga, Li, V, Co, Pt, Mn and Be were interpreted to be mainly inherited from parent materials. Iron, Ba, Sn, Pd and Br were interpreted to be affected by mixed sources. 相似文献
8.
9.
Trace and minor elements in sphalerite: A LA-ICPMS study 总被引：18，自引：0，他引：18
Nigel J. Cook Cristiana L. Ciobanu Allan Pring William Skinner Leonid Danyushevsky Frank Melcher 《Geochimica et cosmochimica acta》2009,73(16):4761-4791
Sphalerite is an important host mineral for a wide range of minor and trace elements. We have used laser-ablation inductively coupled mass spectroscopy (LA-ICPMS) techniques to investigate the distribution of Ag, As, Bi, Cd, Co, Cu, Fe, Ga, Ge, In, Mn, Mo, Ni, Pb, Sb, Se, Sn and Tl in samples from 26 ore deposits, including specimens with wt.% levels of Mn, Cd, In, Sn and Hg. This technique provides accurate trace element data, confirming that Cd, Co, Ga, Ge, In, Mn, Sn, As and Tl are present in solid solution. The concentrations of most elements vary over several orders of magnitude between deposits and in some cases between single samples from a given deposit. Sphalerite is characterized by a specific range of Cd (typically 0.2-1.0 wt.%) in each deposit. Higher Cd concentrations are rare; spot analyses on samples from skarn at Baisoara (Romania) show up to 13.2 wt.% (Cd2+ ↔ Zn2+ substitution). The LA-ICPMS technique also allows for identification of other elements, notably Pb, Sb and Bi, mostly as micro-inclusions of minerals carrying those elements, and not as solid solution. Silver may occur both as solid solution and as micro-inclusions. Sphalerite can also incorporate minor amounts of As and Se, and possibly Au (e.g., Magura epithermal Au, Romania). Manganese enrichment (up to ∼4 wt.%) does not appear to enhance incorporation of other elements. Sphalerite from Toyoha (Japan) features superimposed zoning. Indium-sphalerite (up to 6.7 wt.% In) coexists with Sn-sphalerite (up to 2.3 wt.%). Indium concentration correlates with Cu, corroborating coupled (Cu+In3+) ↔ 2Zn2+ substitution. Tin, however, correlates with Ag, suggesting (2Ag+Sn4+) ↔ 3Zn2+ coupled substitution. Germanium-bearing sphalerite from Tres Marias (Mexico) contains several hundred ppm Ge, correlating with Fe. We see no evidence of coupled substitution for incorporation of Ge. Accordingly, we postulate that Ge may be present as Ge2+ rather than Ge4+. Trace element concentrations in different deposit types vary because fractionation of a given element into sphalerite is influenced by crystallization temperature, metal source and the amount of sphalerite in the ore. Epithermal and some skarn deposits have higher concentrations of most elements in solid solution. The presence of discrete minerals containing In, Ga, Ge, etc. also contribute to the observed variance in measured concentrations within sphalerite. 相似文献
10.
Clemens Reimann Arnold Arnoldussen Peter Englmaier Peter Filzmoser Tor Erik Finne Robert G. Garrett Friedrich Koller Øystein Nordgulen 《Applied Geochemistry》2007
Rock samples and the C-, B- and O-horizons of soils developed on these rocks were collected in forested areas along a 120-km south–north transect in southern Norway, passing through the city of Oslo. Forty samples (1 site/3 km) were analysed for 37 chemical elements (Ag, Al, As, Au, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Se, Sr, Te, Th, Ti, Tl, U, V, W and Zn) following an aqua regia digestion; pH (water extract) and loss on ignition were also determined. The O-horizon soils were additionally analysed for Pt. Gold is the only element that shows a clear anthropogenic peak in the O-horizon soils collected from the city of Oslo. Silver, Au, Bi, Cd, Hg, Pb, S, Sb, Se and Sr all show a strong enrichment in the O-horizon when compared to the underlying C-horizon or the bedrock along the full length of the transect. Neither geology nor anthropogenic input of elements dominate the observed patterns. The most important factors for the observed element concentrations in the O-horizon are weathering, uptake (or rejection) of elements by plants and the kinetics of decay of the organic material in the O-horizon. Climate, especially temperature and precipitation, has an important influence on the formation and decay rates of the organic soil layer. Acid precipitation will delay the decomposition of the organic layer and lead to a natural enrichment of several metals in the O-horizon. Land use change, deforestation and liming can all increase the decay kinetics of organic matter and thus result in a release of the stored element pool. 相似文献
11.
Release of heavy metals during weathering of the Lower Cambrian Black Shales in western Hunan,China 总被引：8，自引：0，他引：8
Weathering of heavy metal enriched black shales may be one of the most important sources of environmental contamination in areas where black shales are distributed. Heavy metal release during weathering of the Lower Cambrian Black Shales (LCBS) in western Hunan, China, was investigated using traditional geochemical methods and the ICP-MS analytical technique. Concentrations of 16 heavy metals, 8 trace elements and P were measured for samples from selected weathering profiles at the Taiping vanadium ore mine (TP), the Matian phosphorous ore mine (MT), and Taojiang stone-coal mine (TJ). The results show that the bedrock at these three profiles is enriched with Sc, V, Cr, Co, Ni, Cu, Zn, Pb, Th, U, Mo, Cd, Sb, Tl, and P. Based on mass-balance calculation, the percentages of heavy metals released (in % loss) relative to immobile element Nb were estimated. The results show significant rates of release during weathering of: V, Cr, Co, Ni, Cu, Zn, U, Mo, Cd, Sn, Sb, and Tl for the TP profile; Sc, Cr, Mn, Co, Ni, Cu, Zn, Pb, Th, Cd, and Sn for the MT profile; and Sc, Mn, Co, Ni, Zn, Th, Cd, Sn, and Tl for the TJ profile. Among these heavy metals, Co, Ni, Zn, Cd, and Sn show very similar features of release from each of the three weathering profiles. The heavy metals released during weathering may affect the environment (especially topsoil and surface waters) and are possibly related to an observed high incidence of endemic diseases in the area. 相似文献
12.
五龙金矿是辽东地区大型岩浆热液型金矿床,163矿脉是矿区内目前发现的最大含矿构造。为进一步探测深部找矿潜力,近几年矿山对163矿脉进行了大量的探采工程,其中在-762 m坑道实施了600 m钻孔。本文在详细编录该钻孔的基础上,对全孔样品进行成矿元素测试工作,利用SPSS软件对所得测试数据进行元素相关性、聚类、因子分析。相关性分析显示,具有显著正相关的元素主要为Bi、W、Cu、Ag、Au和As、Sb、Sn、Zn两组;Mo元素与Sn、Ag、Cu、Bi、W、Sb地素具有显著正相关性,而Pb元素与Cu、Mo、Au、W元素呈显著负相关性,Hg元素与其它元素相关性不明显。聚类分析结果表明,R型聚类在类的距离为5的水平上,这些元素明显可分为3组：Hg、Cu、Pb、Zn、Sn、Mo、As、W;Ag、Au、Sb、Bi。因子分析结果表明,提取3个因子可以反映出12个元素变量64.42%的地球化学信息,F1的主要载荷因子组成为Sn、Ag、As、Zn、Sb, F2的主要载荷因子组成为Au、W、Bi、-Pb, F3的主要载荷因子组成为Hg。根据成矿元素随深度变化特征,结合前人构造叠加晕研究成果,推测该钻孔深部还... 相似文献
13.
The geochemistry and mineralogy of samples collected along depth profiles from an As-rich tailing deposit with abundant calcite was studied to determine the processes that influence the mobility of Fe, Zn, Cu, Ni, Cd, As, Sb, Cr and Tl. In spite of their near neutral pH, almost all of them are acid potential generators. Total concentrations decreased as: Fe > As > Zn > Pb > Cu > Sb > Cd > Cr > Ni > Tl. Soluble contents were lower and followed a slightly different order. Mobility decreased as: Tl > Cd, Zn, Cu, Sb, Ni, As > Fe, Pb > Cr. Higher soluble concentrations of Fe, Cu, Zn, As, Pb, and Ni were found in low-pH samples and of Sb and Tl in near-neutral samples. Sulfide oxidation processes are developing in the tailing’s dam. These processes do not have a trend with depth but occur mainly in acid layers. Near neutral layers formed by primary sulfides and calcite probably correspond to wastes produced from the processing of ore coming mainly from pods within the skarn, and acid layers with abundant secondary minerals from material mined from chimneys and mantos. The presence of calcite influences speciation, neutralizes acid mine drainage (AMD), and decreases the mobility of most toxic metals and metalloids (TMMs). However, a hard-pan layer was not observed in the studied profiles. Retention of TMM within tailings probably occurs through the formation of low solubility metal carbonates and from elevation of pH that promotes Fe hydroxides precipitation that may retain As, Sb and metals. Calcite occurrence promotes As, Cd, Cu, Fe, Zn, Pb, Cd and Cr retention, does not play a role on Tl and Ni mobilization, and increases Sb release. 相似文献
14.
内蒙花敖包特Pb-Zn-Ag多金属矿床原生晕分带特征与深部矿体预测模型 总被引：4，自引：1，他引：3
花敖包特Pb-Zn-Ag多金属矿床构造上位于滨西太平洋成矿域内蒙古大兴安岭成矿带南段, 是一个近年来发现的与白垩纪早期构造岩浆活动有关的隐伏热液脉状矿床.研究表明: (1)矿体原生晕发育, 且分带明显.据其异常强度建立的元素横向分带顺序(从强到弱)为Cd→Pb→Zn→Ag→Sb→In→Hg→As→Cu→Sn→W→Mo→Bi, 排在序列前面的Cd、Pb、Zn、Sb、Ag等5种元素, 可作为远矿指示元素; 排在序列后端的As、Bi、Mo、W等4种元素, 可作为近矿指示元素.(2)根据Grigorian原生晕分带计算方法, 获得矿体原生晕轴向分带序列(自矿体头部至尾部)为Sb→Pb→Cd→Ag→Zn→Hg→Cu→In→As→Bi→Sn→Mo→W, 与Grigorian建立热液矿床标准分带基本一致.(3)构建深部矿体找矿模型, 其预测评价指标(Sb×Pb×Cd×Ag)D/(As×Sn×Mo×W)D在矿体头部为1.30、矿体中上部为0.35、矿体中下部为0.056、矿体尾部为0.005, 这表明该指标随深度的增加有规律地降低, 是预测深部矿体资源潜力的有效指标. 相似文献
15.
A test comparing concentrations of 57 chemical elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, I, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Se, Sm, Sn, Sr, Ta, Tb, Te, Th, Ti, Tl, Tm, U, V, W, Y, Yb, Zn and Zr) determined by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 294 samples of the same bottled water (predominantly mineral water) sold in the European Union in glass and PET bottles demonstrates significant (Wilcoxon rank sum test, α = 0.05) differences in median concentrations for Sb, Ce, Pb, Al, Zr, Ti, Th, La, Pr, Fe, Zn, Nd, Sn, Cr, Tb, Er, Gd, Bi, Sm, Y, Lu, Dy, Yb, Tm, Nb and Cu. Antimony has a 21× higher median value in bottled water when sold in PET bottles (0.33 vs. 0.016 μg/L). Glass contaminates the water with Ce (19× higher than in PET bottles), Pb (14×), Al (7×), Zr (7×), Ti, Th (5×), La (5×), Pr, Fe, Zn, Nd, Sn, Cr, Tb (2×), Er, Gd, Bi, Sm, Y, Lu, Yb, Tm, Nb and Cu (1.4×). Testing an additional 136 bottles of the same water sold in green and clear glass bottles demonstrates an important influence of colour, the water sold in green glass shows significantly higher concentrations in Cr (7.3×, 1.0 vs. 0.14 μg/L), Th (1.9×), La, Zr, Nd, Ce (1.6×), Pr, Nb, Ti, Fe (1.3×), Co (1.3×) and Er (1.1×). 相似文献
16.
Anastassia Yu. Borisova Michel Pichavant Michael Wiedenbeck Frédéric Candaudap 《Geochimica et cosmochimica acta》2006,70(14):3702-3716
The dacite pumice erupted from Mt. Pinatubo on June 15, 1991 (whole-rock, rhyolitic groundmass glasses and homogenized melt inclusions) has been analyzed using inductively coupled plasma-mass spectrometry (ICP-MS), nanosecond and femtosecond laser ablation ICP-MS and secondary ion mass spectrometry (SIMS) to evaluate its ore-forming potential. Data suggest that adakite magmas are metal-rich and concentrate ore metals during magmatic differentiation. Sulfides segregate in limited amounts under the hydrous, oxidizing conditions typical of adakitic magmas resulting in incompatible behavior for Au (6-22 ppb), Cu (26-77 ppm), and Pb, Mo, As, and Sb in melts of dacitic to rhyolitic compositions. Metal transfer from this adakite magma to the coexisting aqueous phase was favored by the peraluminous composition of the rhyolitic melt and high aqueous chloride concentrations. Mass balance calculations suggest that the pre-eruptive aqueous phase could have extracted a minimum of 100 t Au and 5 × 105 t Cu from the Mt. Pinatubo magma. Our data suggest that intrusives having adakitic signatures are genetically associated with Au-Cu and Cu-Mo mineralization, auriferous porphyry copper deposits, and epithermal gold veins. High H2O, Cl, Sr/Y, Pb/Ce, Mo/Ce, As/Ce and Sb/Ce in Mt. Pinatubo melts reflect the contribution of deep fluids derived from subducted sediments and altered MORBs in the dacite genesis. The slab-derived fluids carrying mobile elements are likely responsible for the enrichment of adakite magmas in gold, associated metals and H2O, and may explain the exceptional ore-forming potential of adakite magmatism. 相似文献
17.
流域上游基岩与下游冲积平原土壤化学组成的对比 总被引：2，自引：0，他引：2
对海河水系流域、鄱阳湖水系流域上游的基岩与下游的冲积平原土壤之间化学组成的对比研究显示,下游冲积物土壤的化学组成明显地受源岩成分、形成过程和形成环境的影响。流域上游基岩的一些特征元素在冲积物土壤中被明显地继承,如海河流域基岩和土壤中的CO2、CaO、MgO、FeO、Sr,鄱阳湖流域基岩和土壤中的W、Sn、Bi、U、Th、Pb、Rb、Tl、As、Sb、Se、Hg、Nb、Ta、Hf、B、Be、Ge、Pt、Pd、Y。受形成过程和形成环境的影响,处于暖温带半湿润季风气候下的海河流域冲积平原土壤以极富集CO2、CaO、Na2O、Cl,显著富集MgO、FeO、Sr,富集P、S为特征;而处于亚热带湿润季风气候下的鄱阳湖流域冲积平原土壤则以显著富集Hg、Se和富集Al2O3、Fe2O3H2O^＋、W、Sn、Bi、Mo、U、Th、Pb、Rb、Cs、Tl、Li、Be、B、Ga、Ge、Nb、Ta、Zr、Hf、As、Sb、Co、Cr、Ti、V、Zn、Pt、Pd、REE、Y为特征。无论是海河流域还是鄱阳湖流域的冲积平原土壤,均富集As、Sb、Hg、B、Cl、W、Sn、Bi、Pb、Se、Ge、Li、Cs、Cu、Au、Fe2O3、V、Cr、Ni、Zr、Hf、Y。 相似文献
18.
Steven D. Bussey Paul M. Taufen Bart J. Suchomel Malcolm Ward 《Journal of Geochemical Exploration》1993,47(1-3)
The Bell Springs deposit is a bulk-tonnage, low-grade gold deposit, formed in a hot-spring environment, that is hosted by middle Miocene weakly peralkaline, high-silica rhyolite ash flows and rheomorphic tuffs. Ore grade mineralization over about 460 × 460 m was controlled by northeast- and northwest-trending structures. Sixty-nine soil samples collected along a traverse across the Bell Springs deposit, screened into six mesh size fractions, +10, −10+35, −35+80, −80+120, −120+200, and −200, were treated by low-detection-limit acid digestion/organic extraction procedures, and analyzed by ICP or graphite furnace techniques for Au, Ag, As, Bi, Cd, Cu, Ga, Hg, Mo, Pb, Sb, Se, Te, Tl, and Zn. Twenty-five stream-sediment samples were collected from a drainage crossing mineralization and from a nearby tributary. Sediment size fractions of −200 mesh and −10+200 mesh were analyzed by the same procedures used for soils. In addition, analyses of bulk leachable gold via cyanide leach method (BLEG) was done on bulk −10 mesh sediments.Anomalous Au, Ag, As, Sb, and Mo in all soil size fractions revealed the underlying ore. Areas with anomalous Sb and As were about three times larger than areas with anomalous Au and Ag. Analyses of fine-fractions of stream sediments provided the best-defined Au anomalies in drainages. A multi-element factor calculated by multiplying Au, As, Sb, and Mo reinforced anomalous Au in drainages and correlated well with Bell Springs mineralization. 相似文献
19.
Raimundo Jiménez Ballesta Paz Conde Bueno Juan A. Martin Rubi Rosario Garcia Giménez 《Central European Journal of Geosciences》2010,2(4):441-454
To evaluate trace element soil contamination, geochemical baseline contents and reference values need to be established. Pedo-geochemical baseline levels of trace elements in 72 soil samples of 24 soil profiles from the Mediterranean, Castilla La Mancha, are assessed and soil quality reference values are calculated. Reference value contents (in mg kg?1) were: Sc 50.8; V 123.2; Cr 113.4; Co 20.8; Ni 42.6; Cu 27.0; Zn 86.5; Ga 26.7; Ge 1.3; As 16.7; Se 1.4; Br 20.1; Rb 234.7; Sr 1868.4; Y 38.3; Zr 413.1; Nb 18.7; Mo 2.0; Ag 7.8; Cd 4.4; Sn 8.7; Sb 5.7; I 25.4; Cs 14.2; Ba 1049.3; La 348.4; Ce 97.9; Nd 40.1; Sm 10.7; Yb 4.2; Hf 10.0; Ta 4.0; W 5.5; Tl 2.3; Pb 44.2; Bi 2.2; Th 21.6; U 10.3. The contents obtained for some elements are below or close to the detection limit: Co, Ge, Se, Mo, Ag, Cd, Sb, Yb, Hf, Ta, W, Tl and Bi. The element content ranges (the maximum value minus the minimum value) are: Sc 55.0, V 196.0, Cr 346.0, Co 64.4, Ni 188.7, Cu 49.5, Zn 102.3, Ga 28.7, Ge 1.5, As 26.4, Se 0.9, Br 33.0 Rb 432.7, Sr 3372.6, Y 39.8, Zr 523.2, Nb 59.7, Mo 3.9, Ag 10.1, Cd 1.8, Sn 75.2, Sb 9.9, I 68.0, Cs 17.6, Ba 1394.9, La 51.3, Ce 93.5, Nd 52.5, Sm 11.2, Yb 4.2, Hf 11.3, Ta 6.3, W 5.2, Tl 2.1, Pb 96.4, Bi 3.0, Th 24.4, U 16.4 (in mg kg?1). The spatial distribution of the elements was affected mainly by the nature of the bedrock and by pedological processes. The upper limit of expected background variation for each trace element in the soil is documented, as is its range as a criterion for evaluating which sites may require decontamination. 相似文献
20.
This paper investigates the role played by the fumarolic plume of a passive degassing volcano in the genesis of rock coatings
(RC) and in the introduction and re-distribution of metals and trace elements in the surficial environment. At La Fossa active
volcano (Vulcano Island) and in the surrounding environment RC develop owing to exposure of the ground surface to the volcanic
acid plume produced by the passive degassing of La Fossa. Significant positive anomalies of a wide variety of metals and trace
elements (including Bi, Ag, Se, Te, Sb, Pb, As, Cu, Tl and Cd) were observed either in distal and proximal RC. Most of these
anomalies are interpreted to be the result of the transport and subsequent deposition of trace elements, likely to form volatile
compounds, in the fumarolic plume. Two main processes seem to control the geochemistry of RC: one is represented by the leaching
and subsequent deposition of elements from the proximal toward the distal RC; the other is the direct input of trace elements
carried by the emitted volcanic aerosol. The fact that most of the trace elements (particularly Pb, As, Tl, Bi, Te, Se, Cd)
enriched in the RC of Vulcano are highly toxic and potentially dangerous to health in high concentration, indicates that the
atmospheric metal injection by the quiescently degassing La Fossa volcano together with the subsequent deposition and remobilization
by means of surficial waters may represent an environmental hazard that should be taken into account in evaluating the potential
impact of volcanic air pollution on human health. 相似文献