Change in Field Turbidity and Trace Element Concentrations During Well Purging   总被引：1，自引：0，他引：1  

Jacob Gibs  Zoltan Szabo  Tamara Ivahnenko  Franceska D. Wilde 《Ground water》2000,38(4):577-588

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Linking meteorites to their asteroid parent bodies: The capabilities of dust analyzer instruments during asteroid flybys     

Lisa Maria Eckart  Jon K. Hillier  Frank Postberg  Simone Marchi  Zoltan Sternovsky 《Meteoritics & planetary science》2023,58(10):1449-1468

Linking meteorites to their asteroid parent bodies remains an outstanding issue. Space-based dust characterization using impact ionization mass spectrometry is a proven technique for the compositional analysis of individual cosmic dust grains. Here we investigate the feasibility of determining asteroid compositions via cation mass spectrometric analyses of their dust ejecta clouds during low (7–9 km s⁻¹) velocity spacecraft flybys. At these speeds, the dust grain mass spectra are dominated by easily ionized elements and molecular species. Using known bulk mineral volume abundances, we show that it is feasible to discriminate the common meteorite classes of carbonaceous chondrites, ordinary chondrites, and howardite–eucrite–diogenite achondrites, as well as their subtypes, relying solely on the detection of elements with ionization efficiencies of ≤700 or ≤800 kJ mol⁻¹, applicable to low (~7 km s⁻¹) and intermediate (~9 km s⁻¹) flyby speed scenarios, respectively. Including the detection of water ion groups enables greater discrimination between certain meteorite types, and flyby speeds ≥10 km s⁻¹ enhance the diagnostic capabilities of this technique still further. Although additional terrestrial calibration is required, this technique may allow more unequivocal asteroid-meteorite connections to be determined by spacecraft flybys, emphasizing the utility of dust instruments on future asteroid missions.  相似文献   

Speleothems and pine trees as sensitive indicators of environmental pollution – A case study of the effect of uranium-ore mining in Hungary     

Zoltan Siklosy  Zoltan Kern  Attila Demeny  Sebastian Pilet  Szabolcs Leel-Ossy  Ke Lin  Chuan-Chou Shen  Eva Szeles  Daniel Breitner 《Applied Geochemistry》2011,26(5):666-678

Four decades of U ore production in Hungary provides an opportunity to study the possible environmental effects of mining. The study reveals significant changes in chemical composition of a stalagmite (cave deposit). The good fit between U content changes in the studied deposit and the U ore production rate support the assumption of the relationship with mining activity. An independent chemoenviromental archive, living pine (Pinus sylvestis) trees were also investigated. Data on pine tree cores collected from the same region show different levels of pollution (Cu, Zn, Mn, U) after the 1950s and 1960s, linked to the opening of mines and subsequent dust fallout around the site. Elevated concentrations of detritally derived elements (Si, Al, Th) coupled with a rise in U concentration and change in δ²³⁴U values of the stalagmite suggest increasing amounts of mine-derived dust from 1 to 3 km distance that settled and washed into the karst system. The combined usage of different proxies not only provides historic records for the anthropogenic impact in the environment, but also allows the timing of U concentration increases within the stalagmite and the identification of elemental behavior from the pollution. This study shows that complementary geochemical archives such as stalagmites and tree rings used together can enhance understanding of past environmental contamination.  相似文献   

Attenuation of multiple ScS in various parts of the world   总被引：1，自引：0，他引：1  

W. Winston Chan  Zoltan A. Der 《Geophysical Journal International》1988,92(2):303-314

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Cosmological physics with black holes (and possibly white dwarfs)     

Kristen Menou  Zoltan Haiman  Bence Kocsis 《New Astronomy Reviews》2008,51(10-12):884

The notion that microparsec-scale black holes can be used to probe gigaparsec-scale physics may seem counterintuitive, at first. Yet, the gravitational observatory LISA will detect cosmologically-distant coalescing pairs of massive black holes, accurately measure their luminosity distance and help identify an electromagnetic counterpart or a host galaxy. A wide variety of new black hole studies and a gravitational version of Hubble’s diagram become possible, if host galaxies are successfully identified. Furthermore, if dark energy is a manifestation of large-scale modified gravity, deviations from general relativistic expectations could become apparent in a gravitational signal propagated over cosmological scales, especially when compared to the electromagnetic signal from a same source. Finally, since inspirals of white dwarfs into massive black holes at cosmological distances may permit pre-merger localizations, we suggest that careful monitoring of these events and any associated electromagnetic counterpart could lead to high-precision cosmological measurements with LISA.  相似文献   

Magnetic properties of high-Ti basaltic rocks from the Krušné hory/Erzgebirge MTS. (Bohemia/Saxony), and their relation to mineral chemistry     

Petr Schnabl  Jiří K. Novák  Vladimír Cajz  Miloš Lang  Kadosa Balogh  Zoltan Pécskay  Martin Chadima  Stanislav Šlechta  Tomáš Kohout  Petr Pruner  Jaromír Ulrych 《Studia Geophysica et Geodaetica》2010,54(1):77-94

This study provides new thermomagnetic and petrographic data on specific basaltic rock association from the broader vicinity of the Lou?ná-Oberwiesenthal volcanic centre, western Bohemia/Saxony. Two types of volcanic rocks were recognized there: (i) high-Ti types (3.5–5.2 wt% TiO₂) represented by (mela)nephelinite s.s., and sporadically present (ii) medium-Ti types (2.5–3.5 wt% TiO₂) of olivine nephelinite, nepheline basanite and phonotephrite compositions. In order to examine the rock-magnetic behaviour, they were studied for their variations in the Curie temperature (T_C) and field-dependent susceptibility, spinel group minerals, chemistry and petrology. Magnetic susceptibility of ulvöspinel-rich titanomagnetite, as a dominant magnetic carrier, depends on the amplitude of measured magnetic field, whereas pure magnetite is field-independent. Field dependence parameter ^kHD of the studied basaltic rocks ranges from 0.8 to 18.7%, TiO₂ contents in titanomagnetite range from 12.7 to 20.1 wt.%. TiO₂ content in titanomagnetite does not correlate with whole-rock TiO₂ content (2.8 to 5.6 wt.%). The content of substituted titanium in the sublattice of magnetite is also sensitively reflected in the Curie temperature, ranging from 200 to 580°C. The spinel group minerals are designated as titanomagnetite with the dominance of ulvöspinel, magnetite and magnesioferrite components, or titanomagnetite with the magnetite, ulvöspinel and magnesioferrite components. Only two samples are characterized by a significant presence of Cr-spinel and magnesiochromite components forming cores of titanomagnetites. The titanomagnetite-bearing rocks in the studied area, likewise the low- to medium-Ti basaltic rocks from the ?eské st?edoho?í Mts., provide similar thermomagnetic curves.  相似文献   

Impact of AMD on water quality in critical watershed in the Hudson River drainage basin: Phillips Mine,Hudson Highlands,New York   总被引：1，自引：0，他引：1  

Sivajini Gilchrist  Alexander Gates  Zoltan Szabo  Paul J. Lamothe 《Environmental Geology》2009,57(2):397-409

A sulfur and trace element enriched U–Th-laced tailings pile at the abandoned Phillips Mine in Garrison, New York, releases acid mine drainage (AMD, generally pH < 3, minimum pH 1.78) into the first-order Copper Mine Brook (CMB) that drains into the Hudson River. The pyrrhotite-rich Phillips Mine is located in the Highlands region, a critical water source for the New York metro area. A conceptual model for derivation/dissolution, sequestration, transport and dilution of contaminants is proposed. The acidic water interacts with the tailings, leaching and dissolving the trace metals. AMD evaporation during dry periods concentrates solid phase trace metals and sulfate, forming melanterite (FeSO₄·7H₂O) on sulfide-rich tailings surfaces. Wet periods dissolve these concentrates/precipitates, releasing stored acidity and trace metals into the CMB. Sediments along CMB are enriched in iron hydroxides which act as sinks for metals, indicating progressive sequestration that correlates with dilution and sharp rise in pH when mine water mixes with tributaries. Seasonal variations in metal concentrations were partly attributable to dissolution of the efflorescent salts with their sorbed metals and additional metals from surging acidic seepage induced by precipitation.  相似文献   

Occurrence and geochemistry of radium in water from principal drinking-water aquifer systems of the United States     

Zoltan Szabo  Vincent T. dePaul  Jeffrey M. Fischer  Thomas F. Kraemer  Eric Jacobsen 《Applied Geochemistry》2012

A total of 1270 raw-water samples (before treatment) were collected from 15 principal and other major aquifer systems (PAs) used for drinking water in 45 states in all major physiographic provinces of the USA and analyzed for concentrations of the Ra isotopes ²²⁴Ra, ²²⁶Ra and ²²⁸Ra establishing the framework for evaluating Ra occurrence. The US Environmental Protection Agency Maximum Contaminant Level (MCL) of 0.185 Bq/L (5 pCi/L) for combined Ra (²²⁶Ra plus ²²⁸Ra) for drinking water was exceeded in 4.02% (39 of 971) of samples for which both ²²⁶Ra and ²²⁸Ra were determined, or in 3.15% (40 of 1266) of the samples in which at least one isotope concentration (²²⁶Ra or ²²⁸Ra) was determined. The maximum concentration of combined Ra was 0.755 Bq/L (20.4 pCi/L) in water from the North Atlantic Coastal Plain quartzose sand aquifer system. All the exceedences of the MCL for combined Ra occurred in water samples from the following 7 PAs (in order of decreasing relative frequency of occurrence): the Midcontinent and Ozark Plateau Cambro-Ordovician dolomites and sandstones, the North Atlantic Coastal Plain, the Floridan, the crystalline rocks (granitic, metamorphic) of New England, the Mesozoic basins of the Appalachian Piedmont, the Gulf Coastal Plain, and the glacial sands and gravels (highest concentrations in New England).  相似文献   

Geological and geomorphological problems caused by transportation and industry     

Lorant David  Zoltan Ilyes  Zoltan Baros 《Central European Journal of Geosciences》2011,3(3):271-286

Alterations in topography due to the construction of transport infrastructure and industrial development are the results of rather complex processes. The impact of transport constructions upsetting (topographic) equilibrium is manifested in a relatively narrow strip, and, mostly, through producing abnormally steep slopes, in reducing relief stability. The earthworks for transport routes are themselves also landscape-forming factors whereas in the case of industrial developments, planation is usually mentioned. Topographic changes related to the construction of transport infrastructure and industrial development are discussed historically in this chapter. Among the direct impacts of the first are those related to the construction of Roman and Medieval roads, hollow roads in loess, public roads, motorways, railways, canals, tunnels and airports; while of the second are those of early mining and metallurgy, cellars, sludge reservoirs, slag cones and fly-ash reservoirs, cooling ponds, industrial parks, shopping centres and waste disposal sites. Of the indirect ones, an introduction is given to impacts of surface sealing, changes in runoff, the ‘waterfall effect,’ as well as to environmental impacts under permafrost conditions.  相似文献   

四合屯玄武岩斑晶中单个熔体包裹体元素组成及其对岩浆演化的指示   总被引：7，自引：0，他引：7  

张春来  刘勇胜  高山  Zoltan ZAJACZ  胡兆初  高长贵 《地球化学》2011,40(2):109-125

玄武岩斑晶中熔体包裹体成分特征可以推断玄武岩源区物质组成,反映岩浆形成演化过程。利用LA—ICPMS对四合屯义县组玄武岩橄榄石、单斜辉石斑晶中单个熔体包裹体的元素组成进行了分析测试。研究结果表明,橄榄石、单斜辉石斑晶中的熔体包裹体在主、微量元素含量上表现出了比全岩更大的变化范围,但微量元素分配特征总体和全岩一致。单斜辉石斑晶中包裹体的CaO含量、CaO／Al2O3比值和Cr2O3含量随着单斜辉石Mg#值的降低而降低,反映了单斜辉石结晶分离的影响,Al2O3与Sr之间的显著相关关系则记录了斜长石结晶分离作用的影响,MgO—Ni和MgO—CaO／Al2O3的变化则反映了橄榄石的分离结晶作用。包裹体元素组成变化总体受橄榄石、单斜辉石和斜长石的结晶分离作用控制。结合前人研究成果,认为四合屯玄武岩在微量元素和同位素组成上的壳源组分特征可能部分地继承自原岩（即橄榄岩＋榴辉岩部分熔融体反应形成的（橄榄）辉石岩）,而不是岩浆上升过程中受地壳岩石混染的结果。高Mg#值单斜辉石斑晶中少量高Mg馆、高Si含量,低CaO、TiO2、Al2O3和微量元素含量的熔体包裹体反映玄武岩浆上升过程中受到了S1质岩石的混染,这与义县组玄武岩下伏地层为长城系大红裕组石英岩、石英砂岩的地质特征一致。因此,高Fo橄榄石斑晶中的熔体包裹体比采用向全岩中简单添加橄榄石方式计算出的原始熔体可能更能真实反映原始熔体组成。  相似文献