Arctic catchment as a sensitive indicator of the environmental changes: distribution and migration of metals (Svalbard)

Arctic regions experience metal pollution, despite their remote location, and the distribution and migration of those metals determine their potential impact on the local environment. Here, a High-Arctic catchment (Revelva, Svalbard) located remotely from human-induced pollution sources is studied with respect to the distribution and migration of chosen trace elements (Ag, Al, As, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Cs, Mo, Ni, Pb, Sb, Se, Sr, Tl, U, V and Zn) in surface waters. The metal concentrations fluctuated in 2010–2012 between 0.01 and 354 μg L^?1, the highest mean-weighted concentration noted for Sr (42.5 μg L^?1). The concentrations in the river water were likely influenced by both natural and human-activity-related processes. These factors can produce substances of the same chemical composition (e.g. carbon dioxide, sulphur dioxide and metals may be emitted both by a volcanic eruption and by industrial sources). Therefore, chemometric techniques were used in the current paper to distinguish the multiple sources of pollution in the Revelva catchment. The authors were seeking to determine whether there is indeed evidence for contamination, sufficient to cause environmental damage in polar region. As a result, it was shown that the long-range transport could play an important role in shaping the metal concentration profile of this Arctic tundra environment, capturing both the influence of volcanic eruptions within the region and the human activity in a range of distances from the study site.     

Trace elements in primitive meteorites—VI. Abundance patterns of thirteen trace elements and interelement relationships in unequilibrated ordinary chondrites

Neutron activation analysis was used to determine As, Au, Bi, Cd, Co, Cu, Ga, In, Sb, Se, Te, Tl and Zn in 13 different unequilibrated ordinary chondrites (UOC), i.e. those having chemicallyinhomogeneous silicates. This study together with prior data completes our coverage of this group of 23 primitive chondrites. Four elements are quite variable in UOC (Cd—20 x, In—30 x, Bi—300 x and Tl—1300 x), the others varying by 2–8 x. Three highly-depleted elements—Bi, In and Tl—are richer by 5–35 x in unequilibrated chondrites than in their equilibrated congeners. All 3 elements vary directly in characteristic fashion with disequilibrium parameters for olivine and pyroxene in UOC and generally with petrologic type 3 > 4 > 5 > 6. The data do not provide unambiguous evidence for nebular fractionation of siderophile elements. Examination of statistically-significant interelement relationships among various ordinary chondrite populations involving 34 elements reveals patterns distinct from those of other chondritic groups. These patterns reflect nebular metal-silicate fractionation which preceded or accompanied thermal fractionation. The results point to significant differences in the formation of primitive carbonaceous, enstatite and ordinary chondrites.     

Atmospheric sources and sinks of volcanogenic elements in a basaltic volcano (Etna, Italy)

This study reports on the first quantitative assessment of the geochemical cycling of volcanogenic elements, from their atmospheric release to their deposition back to the ground. Etna’s emissions and atmospheric depositions were characterised for more than 2 years, providing data on major and trace element abundance in both volcanic aerosols and bulk depositions. Volcanic aerosols were collected from 2004 to 2007, at the summit vents by conventional filtration techniques. Precipitation was collected, from 2006 to 2007, in five rain gauges, at various altitudes around the summit craters. Analytical results for volcanic aerosols showed that the dominant anions were S, Cl, and F, and that the most abundant metals were K, Ca, Mg, Al, Fe, and Ti (1.5-50 μg m⁻³). Minor and trace element concentrations ranged from about 0.001 to 1 μg m⁻³. From such analysis, we derived an aerosol mass flux ranging from 3000 to 8000 t a⁻¹. Most analysed elements had higher concentrations close to the emission vent, confirming the prevailing volcanic contribution to bulk deposition. Calculated deposition rates were integrated over the whole Etna area, to provide a first estimate of the total deposition fluxes for several major and trace elements. These calculated deposition fluxes ranged from 20 to 80 t a⁻¹ (Al, Fe, Si) to 0.01-0.1 t a⁻¹ (Bi, Cs, Sc, Th, Tl, and U). Comparison between volcanic emissions and atmospheric deposition showed that the amount of trace elements scavenged from the plume in the surrounding of the volcano ranged from 0.1% to 1% for volatile elements such as As, Bi, Cd, Cs, Cu, Tl, and from 1% to 5% for refractory elements such as Al, Ba, Co, Fe, Ti, Th, U, and V. Consequently, more than 90% of volcanogenic trace elements were dispersed further away, and may cause a regional scale impact. Such a large difference between deposition and emission fluxes at Mt. Etna pointed to relatively high stability and long residence time of aerosols in the plume.     

辽宁北票四合屯地区鸟类集群死亡原因新解

通过对鸟类生理特点和生活习性的考察,该地域火山孕育与喷发关系的探析,碳、砷、锑、铋、铅的氢化物、一氧化碳生成条件、理化性质及其毒性的讨论,认为鸟类在火山喷发前夜即被弥漫在空气中大量剧毒易挥发的氢化物、一氧化碳致命,集群死亡,接着火山喷发,火山灰将它们深埋,演化成鸟类化石.     

Are C1 chondrites chemically fractionated? a trace element study

Six C1 chondrite samples and a C2 xenolith from the Plainview H5 chondrite were analyzed by radiochemical neutron activation for the elements Ag, Au, Bi, Br, Cd, Ce, Cs, Eu, Ge, In, Ir, Lu, Nd, Ni, Os, Pd, Pt, Rb, Re, Sb, Se, Sn, Tb, Te, Tl, Yb, and Zn. The data were combined with 9 earlier analyses from this laboratory and examined for evidence of chemical fractionation in C1 chondrites.A number of elements (Br, Rb, Cs, Au, Re, Os, Ni, Pd, Sb, Bi, In, Te) show small but correlated variations. Those of the first 8 probably reflect hydrothermal alteration in the meteorite parent body, whereas those of Sb, Bi, In, and Te may at least in part involve nebular processes. Br and Au show systematic abundance differences from meteorite to meteorite, which suggests hydrothermal transport on a kilometer scale. The remaining elements vary from sample to sample, suggesting transport on a centimeter scale.There is no conclusive evidence for nebular fractionation affecting C1 's. Though C1 chondrites have lower $\text{Zr}\text{Hf}$ and $\text{Ir}\text{Re}$ ratios than do other chondrite classes, these ratios vary in other classes, suggesting that those classes rather than C1's are fractionated. Three fractionation-prone REE—Ce, Eu, and Yb have essentially the same relative abundances in C1's and all other chondrite classes, and hence apparently are not fractionated in C1's. We did not confirm the large Tb and Yb variations in C1's reported by other workers.We present revised mean C1 abundances for 35 elements, based on the new data and a critical selection of literature data. Changes are generally less than 10%, except for Br, Rb, Ag, Sb, Te, Au, and the REE.The Plainview C2 xenolith has normal trace element abundances, except for 3 elements falling appreciably above the C2 range: Rb, Cs, and Bi. Hydrothermal alteration may be the reason for all 3, though nebular fractionation remains a possibility for Bi.     

The use of geochemical indicator elements in the exploration for hot water sources within geothermal fields

Soils, rocks, altered rocks, hot and cold waters, and hot spring precipitates were sampled within and on the outskirts of geothermal fields in China. The contents of thirty trace elements in soils and rocks show that Hg, As, Sb, Bi, Li, Rb, Cs, Au, Ag, B, W, Sn, Pb, Zn, Mn, Ni and Co can serve as direct and indirect indicators for geothermal field exploration. Large amounts of data indicate that Hg, As and Sb are the best indicators of hot water sources. Altered rocks contain higher Hg, As, Sb, Bi and Be than unaltered rocks. Based on their abundances in hot waters, it is suggested that the following elements may be used as hydrochemical indicators of high-temperature hot-water geothermal systems: K⁺, Na⁺, Ca²⁺, Mg²⁺, SO²⁻₄, HCO⁻₃, F⁻, Cl⁻, SiO₂, HBO₂, CO₂, pH, total dissolved solids and hydrochemical types, as well as Hg, As, Sb, Be, Li, Rb and Cs. Modern precipitates associated with hot springs have high contents of Ba, Be, Fe, Ti, Hg, As, Sb and Bi. Using these geochemical data, the authors have had much success in locating hot water drill sites within geothermal fields. Case histories are described for five geothermal areas.     

Results for Rarely Determined Elements in MPI-DING, USGS and NIST SRM Glasses Using Laser Ablation ICP-MS

New analytical results are reported for rarely determined elements Be, B, Ge, As, Mo, Rh, Pd, Ag, Cd, In, Sn, Sb, W, Re, Ir, Pt, Au, Tl and Bi in MPI‐DING and USGS (BCR‐2G, BHVO‐2G, BIR‐1G) silicate glasses and the NIST SRM 610‐614 synthetic soda‐lime glasses using 193 nm ArF excimer laser ablation and quadrupole ICP‐MS. The method used involved external calibration against GOR132‐G for Ir and NIST SRM 610 for other elements, internal standardisation using Ca, and ablation with a crater diameter of 160 μm and a pulsed laser repetition rate of 10 Hz. Small amounts of nitrogen (5 ml min^?1) were added to the central channel gas of the plasma to improve the limits of detection for most of these elements by a factor of 1.2–2.5 and to reduce the oxide interference level to 0.02% (ThO⁺/Th⁺). Under these conditions, the LODs for most of these rarely determined elements were within the range 0.1 to 10 ng g^?1. The operating conditions that were required to minimise ICP‐induced fractionation (U⁺/Th⁺≈ 1) in the mode without nitrogen were accompanied by a 50–60% reduction in sensitivity for elements such as Ca, Au and Pt. In contrast, ICP‐induced fractionation could be minimised (U⁺/Th⁺≈ 1) with no loss of analyte sensitivity in the nitrogen mode. Interferences of CuAr⁺, ZnAr⁺, Cd⁺, Pb²⁺ and Sn⁺ on Pd⁺, Rh⁺, Cd⁺ and In⁺ were corrected. Oxide interferences were not considered due to their lower production rate. Analytical precision, as given by one relative standard deviation (% RSD) was less than 15% for most of the elements present at concentrations greater than 0.1 μg g^?1. A significant negative correlation was found between logarithmic concentration and logarithmic RSD, with a correlation coefficient of ?0.76. This trend indicates that possible chemical heterogeneities for most of these elements are smaller than the analytical uncertainty. Our results for Be, B, Ge, Sb and W are generally in good agreement with their reference values. In contrast, other elements in many of the reference glasses have only information values, upper limits or even no values, which restrict any detailed evaluation of the accuracy of the determined values. However, concentrations from multiple isotopes of one element analysed in this study showed excellent agreement, which guarantee the quality of our data to a certain extent.     

基于FY-3A遥感数据的冰岛火山灰云识别

2010年4月至5月期间冰岛艾雅法拉火山喷发造成了欧洲航空业史无前例的瘫痪以及巨大的经济损失,其严重影响再次显示,对火山灰云进行有效监测的重要性。火山灰云是由火山碎屑物及气体组成的混合物,火山碎屑物主要由直径小于2mm的岩石、矿物、火山玻璃碎片组成,火山灰云中的气体主要包括水汽、CO2、SO2、H2S、CH4、CO、HCL、HF、HBr、和NOx等。使用具有我国自主知识产权的FY-3A/VIRR数据,对此次艾雅法拉火山喷发的不同阶段选取具有典型风向变化的日期,采用分裂窗亮温差算法(SWTD)、RGB真彩色方法、中红外波段数据等进行火山灰云的识别,并将结果与冰岛地区的火山灰监测报告以及前人的研究结果进行对比研究,结果表明:火山喷发初期火山灰云中较高含量的水汽会补偿反面吸收的影响,妨碍分裂窗亮温差算法(SWTD)对火山灰云的识别,而中红外波段数据因对高温物体的敏感性,不受水汽的影响,对喷发初期较高温度的火山灰云识别效果较好;在喷发中期,火山灰云浓度较大时三种方法均表现良好,卫星图像中火山灰云的位置信息及漂移方向均非常清晰,且同气象条件相吻合,验证了识别方法的正确性。该项结果表明,具有我国自主知识产权的FY-3A数据能够达到监测火山灰云的目的,而如何更加清晰地界定火山灰云的边界位置以及更加准确的计算出火山灰云的浓度需要进一步的深入研究。     

Trace elements in ocean ridge basalt glasses: implications for fractionations during mantle evolution and petrogenesis

Seven well-documented and fresh glassy selvages from ocean floor basalt pillows were analyzed by radiochemical neutron activation analysis for Ag, Au, Bi, Br, Cd, Cs, Ge, In, Ir, Ni, Os, Pd, Rb, Re, Sb, Se, Te, Tl, U and Zn. The samples came from active spreading centers in the Indian and Atlantic Ocean. Glasses from DSDP Leg 24, site 238 (Indian Ocean) have a somewhat peculiar trace element pattern, but this is thought to reflect secondary processes operating at shallow depth, not an anomalous source region in the mantle. Our data rather indicate that heterogeneities in the mantle are confined to the highly incompatible lithophile elements.Chemical fractionations during petrogenesis of tholeiitic basalts are discussed in the light of literature data for primitive peridotitic upper mantle nodules. (Ir, Os), Au, Pd, Ni and Re are strongly fractionated from each other in igneous processes; the unfractionated chondritic mantle pattern thus imposes firm constraints on mantle evolution models. The potentially chalcophile elements Ag, Cd, In and Zn do not behave differently from lithophile elements of the same valency and comparable ionic radius. Residual sulfides are not abundant enough to efficiently control the partitioning of these elements during basalt petrogenesis. However, the poor coherence of Tl to Rb and U in ocean floor basalts could point to retention of Tl by residual sulfides during depletion of the MORB source regions. Sb is strongly depleted in the source regions of ocean ridge basalts; most likely, it was present as a highly incompatible Sb⁵⁺ cation. The limited Rb/Cs fractionation in oceanic tholeiites, as opposed to continental tholeiites and acidic rocks, appears to reflect the low abundance of volatile constituents and hydrous silicates in normal ocean ridge basalts.     

以多硫、多碘化合物为缓冲剂发射光谱法测定化探样品中As、Sb、Bi、Cd、Tl、In 元素

本方法建立了以多硫化合物、多碘化合物为缓冲剂(液体缓冲剂),上电极为光谱纯石墨电极、下电极为光谱纯石墨加罩电极的方式,采用控制试样法绘制工作曲线,电弧发射光谱法同时测定区域地球化学样品中As、Sb、Bi、Cd、Tl、In等6元素的测定方法。方法检出限为As1.0μg/g,Sb0.2μg/g,Bi0.1μg/g,Cd0.05μg/g,Tl0.1μg/g,In0.01μg/g;精密度(RSD,n=12)为As8.36%,Sb7.17%,Bi7.60%,Cd7.39%,Tl7.13%,In6.76%。方法用于测定国家一级标准物质GSD-1～GSD-12中As、Sb、Bi、Cd、Tl、In,测定值与标准值或参考值吻合。通过对1:50000区域地球化学调查样品中As、Sb、Bi、Cd、Tl、In实际分析,结果成图效果良好,具有简便快捷、成本低、检出限低、精度高等特点。     

Concentration and distribution of elements in Late Permian coals from western Guizhou Province,China

With the aim of better understanding geochemistry of coal, 71 Late Permian whole-seam coal channel samples from western Guizhou Province, Southwest China were studied and 57 elements in them were determined. The contents of Al, Ca, Co, Cr, Cu, Fe, Ga, Hf, K, Li, Mn, Mo, Nb, Ni, Sn, Ta, Ti, Th, U, V, Zr, and REEs in the Late Permian coals from western Guizhou Province are higher than the arithmetic means for the corresponding elements in the US coals, whereas As, Ba, Br, F, Hg, P, Se, and Tl are lower. Compared to common Chinese coals, the contents of Co, Cr, Cu, Ga, Hf, Li, Mn, Mo, Ni, Sc, Sn, Ti, U, V, Zn, and Zr in western Guizhou coals are higher, and As, F, Hg, Rb, Sb, Tl, and W are lower. Five groups of elements may be classified according to their mode of occurrence in coal: The first two, Group A, Tm–Yb–Lu–Y–Er–Ho–Dy–Tb–Ce–La–Nd–Pr–Gd–Sm, and Group B, As–Sr–K–Rb–Ba–F–Ash–Si–Sn–Ga–Hf–Al–Ta–Zr–Be–Th–Na, have high positive correlation coefficients with ash yield and they show mainly inorganic affinity. Some elements from Group B, such as Ba, Be, Ga, Hf, and Th, are also characterized by significant aluminosilicate affinity. In addition, arsenic also exhibits high sulfide affinity (r_S–Fe>0.5). The elements, which have negative or lower positive correlation coefficients with ash yield (with exceptions of Bi, Cs, Nb, Mn, Se, and Ti), are grouped in other four associations: Group C, Cr–V–Mo–U–Cd–Tl; Group D, Hg–Li–Sc–Ti–Eu–Nb–Cs–W; Group E, Bi–Sb; and Group F, Co–Ni–Cu–Pb–Zn–Mg–Se–Ca–Mn–S–Fe. The correlation coefficients of some elements, including Co, Cr, Cu, Fe, Hg, Li, Mo, Ni, P, S, Sc, U, V, and Zn, with ash yield are below the statistically significant value. Only Cr and Cu are negatively correlated to ash yield (−0.07 and −0.01, respectively), showing intermediate (organic and inorganic) affinity. Manganese and Fe are characterized by carbonate affinity probably due to high content of epigenetic veined ankerite in some coals. Phosphorus has low correlation coefficients with any other elements and is not included in these six associations. There are five possible genetic types of enrichment of elements in coal from western Guizhou Province: source rock, volcanic ash, low-temperature hydrothermal fluid, groundwater, and magmatic hydrothermal inputs.     

El Chichón volcano, April 4, 1982: volcanic cloud history and fine ash fallout

This retrospective study focuses on the fine silicate particles (<62 µm in diameter) produced in a large eruption that was otherwise well studied. Fine particles represent a potential hazard to aircraft, because as simple particles they have very low terminal velocities and could potentially stay aloft for weeks. New data were collected to describe the fine particle size distributions of distal fallout samples collected soon after eruption. Although, about half of the mass of silicate particles produced in this eruption of ~1 km³ dense rock equivalent magma were finer than 62 µm in diameter, and although these particles were in a stratospheric cloud after eruption, almost all of these fine particles fell to the ground near (<300 km) the volcano in a day or two. Particles falling out from 70 to 300 km from the volcano are mostly <62 µm in diameter. The most plausible explanation for rapid fallout is that the fine ash nucleates ice in the convective cloud and initiates a process of meteorological precipitation that efficiently removes fine silicates. These observations are similar to other eruptions and we conclude that ice formation in convective volcanic clouds is part of an effective fine ash removal process that affects all or most volcanic clouds. The existence of pyroclastic flows and surges in the El Chichón eruption increased the overall proportion of fine silicates, probably by milling larger glassy pyroclasts.     

Pedo-geochemical baseline content levels and soil quality reference values of trace elements in soils from the Mediterranean (Castilla La Mancha, Spain)

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.     

Thermal metamorphism of primitive meteorites—VIII. Noble gases,carbon and sulfur in Allende (C3) meteorite heated at 400–1000°C

Noble gases, C and S are lost from Allende samples heated for 1 week at temperatures of 400–1000°C in a low pressure environment. In the extreme, losses of ³He and ⁴He are ~ 100 × while for C. S and Ne, Ar and Kr isotopes and ¹³²Xe. these are ≤10 ×. Except for He, these losses are less severe than those of Bi or Tl from samples heated in the same runs. Significant He. Ne and Ar isotopic fractionation during heating indicates preferential outgassing of specific reservoirs. Apparent activation energies for all species generally indicate loss controlled by a diffusive process. Next to He, ⁴⁰Ar is the most labile of those species considered here but still less so than Bi or Tl. L-group (but not H- or LL-group) chondrites may have lost mobile elements like Tl while being outgassed after late impact-associated heating. A less likely alternative possibility involving a collateral relation between condensation conditions and depth in a parent object may also explain the L-group trend.     

H-chondrites: Trace element clues to their origin

We have analyzed 10 H-chondrites for 20 trace elements, using RNAA. The meteorites included 4 of petrologic type 4 and 2 each of types 3, 5 and 6.The data show that H-chondrites are not isochemical. H3's are depleted by some 10% not only in Fe (Dodd, 1976), but also in the siderophiles Os, Re, Ir, Ni, Pd, Au, and Ge. Moreover, the abundance pattern of siderophiles varies systematically with petrologic type. As similar fractionations of REE have been observed by Nakamura (1974), it appears that both the proportions and compositions of the main nebular condensates varied slightly during accretion of the H-chondrites. Thus the higher petrologic types are independent nebular products, not metamorphosed descendants of lower petrologic types.Abundances of highly volatile elements (Cs, Br, Bi, Tl, In, Cd, Ar³⁶) correlate with petrologic type, declining by ≤ 10^?3 from Type 3 to Type 6. The trends differ from those for artificially heated Type 3's (Ikramuddinet al., 1977b; Herzoget al., 1979), but agree passably with theoretical curves for nebular condensation. Apparently the low volatile contents of higher petrologic types are a primary feature, not the result of metamorphic loss.The mineralogy of chondrites suggests that they accreted between 405 K (absence of Fe₃O₄) and 560 K (presence of FeS), and the abundances of Tl, Bi, and In further restrict this interval to 420–500 K. Accretion at 1070 ± 100 K, as proposed by Hutchisonet al. (1979, 1980), leads to some extraordinary problems. Volatiles must be injected into the parent body after cooling, which requires permeation of the body by 10¹¹ times its volume of nebular gas. This process must also achieve a uniform distribution of the less volatile elements (Rb, Cu, Ag, Zn, Ga, Ge, Sn, Sb, Se, F), without freezeout in the colder outer layers.Factor analysis of our data shows 3 groupings: siderophiles (Os, Re, Ir, Ni, Pd, Au, and Ge), volatiles (Ag, Br, In, Cd, Bi, and Tl) and alkalis (Rb and Cs). The remaining 5 elements (U, Zn, Te, Se, and Sb) remain unassociated.     

Comparative petrophysical and geochemical characteristics of thermal and volcanic ash from southeastern India

This paper examines the difference in the geophysical and chemical characteristic of the volcanic ash and thermal fly ash to evaluate environmental pollution. Natural volcanic ash (VA) samples from Sagirelu, Cuddapah dist., Andhra Pradesh and thermal fly ash (FA) samples from the Thermal Power Station, Ennore, Chennai, were collected, analysed and compared. The particle sizes of the ash samples were determined using the laser particle size analyzer and the different surface morphological characters were studied using SEM analyses. The chemical components such as pH, major oxides, trace metals and mineral compositions were determined using pH metre, XRF and XRD methods. pH value of the volcanic ash varies from 8.5 to 8.9 indicating its alkalinity (8.5 to 9) in volcanic ash, while the thermal ash is neutral to mildly alkaline with pH varying from 6 to 7.5. Both the ash samples have higher concentration value in SiO₂ (VA - 69.25%, FA - 46%) in major oxides and Cl (VA - 0.8%, FA - 0.1%) in trace elements. Quartz is the dominant mineral in both the types of ash, however, the volcanic ash has amorphous silica, while the fly ash contains crystalline quartz.     

Automated forecasting of volcanic ash dispersion utilizing Virtual Globes

There are over 100 active volcanoes in the North Pacific (NOPAC) region, most of which are located in sparsely populated areas. Dispersion models play an important role in forecasting the movement of volcanic ash clouds by complementing both remote sensing data and visual observations from the ground and aircraft. Puff is a three-dimensional dispersion model, primarily designed for forecasting volcanic ash dispersion, used by the Alaska Volcano Observatory and other agencies. Since early 2007, the model is in an automated mode to predict the movement of airborne volcanic ash at multiple elevated alert status volcanoes worldwide to provide immediate information when an eruption occurs. Twelve of the predictions are within the NOPAC region, nine more within the southern section of the Pacific ring of fire and the others are in Europe and the Caribbean. Model forecasts are made for initial ash plumes ranging from 4 to 20 km altitude above sea level and for a 24-h forecast period. This information is made available via the Puff model website. Model results can be displayed in Virtual Globes for three-dimensional visualization. Here, we show operational Puff predictions in two and three-dimensions in Google Earth^®, both as iso-surfaces and particles, and study past eruptions to illustrate the capabilities that the Virtual Globes can provide. In addition, we show the opportunity that Google Maps^® provides in displaying Puff operational predictions via an application programming web interface and how radiosonde data (vertical soundings) and numerical weather prediction vertical profiles can be displayed in Virtual Globes for assisting in estimating ash cloud heights.     

Luna 20 soil: abundance of 17 trace elements

Luna 20 soil is remarkably similar to Apollo 16 soil, in its content of 17 mainly volatile or siderophile elements: Ag, Au, Bi, Br, Cd, Cs, Ge, In, Ir, Rb, Re, Sb, Se, Te, Tl, U, and Zn. Like other highland soils, it seems to contain an ancient meteoritic component of fractionated, volatile-poor composition. The bulk soil has a high $\text{Tl}\text{Cs}$ ratio (9.4 × 10^?2), similar to that in Apollo 16 soils (5.4 × 10^?2), but higher than that in samples from other sites (1.1 × 10^?2). It is severely contaminated with Ag, Cd, Re, and Sb, judging from a comparison with a 1.7 mg soil breccia sample from the coarse fraction of the soil.     

Environmental impact of the acid fumarolic plume of a passively degassing volcano (Vulcano Island,Italy)

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.     

Geochemical mapping in northern Honshu,Japan

Geochemical mapping of northern Honshu in the Northeast Japan Arc was carried out using stream sediments at a sampling density of one sample per 130 km². More than 50 elements were determined in 395 stream sediment samples (<0.18 mm fraction). In geochemical maps, areas with especially low concentrations of large ion lithophile elements (LILE), Be and Li widely overlap with the distribution of Quaternary volcanic rocks along the volcanic front. The areas rich in mafic elements are associated with mafic rocks in many cases. On a regional scale, Ni, Cr and Cu contents are higher in the eastern Paleozoic–Mesozoic basement zone, Pb and Tl tend to be higher on the western zones, and Zn and Cd are high in the western back-arc zone. The areas especially rich in Cu, Zn, Cd, Pb, Bi and Tl coincide with the distribution of large mineral deposits. High concentrations related to Kuroko, hydrothermal-vein, and skarn-type deposits are recognized. High values of As and Sb are related to active geothermal areas near volcanoes and ore deposits. Chemical variations of K, Ce, Th and Sn in the stream sediments are concordant with chemical variations in major rocks. The median and mean concentrations for the stream sediments in northern Honshu, showing arc signatures, are lower in Rb, Cs, Th, Li, K, Be, Ta, LREE, Ni, Hg and Sn, and higher in Sc, Ca and Cd relative to the whole area of Japan, largely because of the contribution of Cenozoic island-arc volcanic rocks that are generally poor in incompatible elements. The averaged chemical compositions of the stream sediments for the geologic zones show systematic variations of many elements. The contrasting variations of LREE and Th contents, which are lower in the zones of Cenozoic rocks relative to the zones of pre-Neogene basements, reflect the regional variations in the main rocks, and also reflect the change of geological settings of the studied area from the continental margin to an island arc during the Cenozoic.