Geostatistical evaluation of lead and zinc concentration in soils of an old mining area with complex land management

This study is aimed at detailed statistical and geostatistical investigation of lead and zinc concentration in an old mining area located in the eastern part of the Upper Silesian Industrial Region. This area is rich in lead and zinc ores whose intense extraction dates back to the tenth century ad. The complexity of the area results from historical and current mining activities, as well as from a variety of different types of land management and complex geological conditions. Almost 1,000 collected soil cores were divided into two subsets: those collected at the depth of up to 20 cm and the those collected at the depth from 40 to 60 cm. Extensive analyses considered geological substrata in terms of spatial variability and spatial distributions, the type of land management, geoaccumulation indexes and enrichment factors. Lead and zinc concentration was several times higher on depths ranging from 40 to 60 cm beneath the soil surface than in the 20-cm topsoil. The results showed that clearer spatial dependence was observed for deeper soil layers then for the topmost ones, especially near mines where anthropogenic factors predominated over lithogenic ones. Weak spatial dependence was accompanied by high values of the geoaccumulation index. The lowest concentrations of pollution with geoaccumulation index below 0 and enrichment factor up to 5 observed in the forest were caused by low anthropogenic pressure and the presence of sandy soils, less capable of accumulating heavy metals.     

Use of the temperature–vegetation dryness index for remote sensing grassland moisture conditions in the vicinity of a lignite open-cast mine

Anthropogenic activities, especially resulting in changes in the water conditions, usually disturb biological and agricultural functions of grasslands, leading to their degradation, often on large areas. Remote sensing observations of such changes in grassland ecosystems evoke a great interest, but they are still a difficult task, especially when performed on industrial and mining areas. This paper presents a new effective method of remote sensing of grassland moisture conditions based on temperature–vegetation dryness index (TVDI) calculated from free Landsat imagery, and employing the TVDI spatial variability estimated from a semivariance analysis. The practical applicability of the method is demonstrated on the example of monitoring of the extensive neighborhood of lignite open-cast mine within a period of a few years. Besides, the developed method was validated at the studied area, using in situ information. Thus, we demonstrated that TVDI may serve as an effective indicator of grassland moisture conditions, even in problematic areas.     

Timing of glacier advances and climate in the High Tatra Mountains (Western Carpathians) during the Last Glacial Maximum

During the Last Glacial Maximum (LGM), long valley glaciers developed on the northern and southern sides of the High Tatra Mountains, Poland and Slovakia. Chlorine-36 exposure dating of moraine boulders suggests two major phases of moraine stabilization, at 26–21 ka (LGM I — maximum) and at 18 ka (LGM II). The dates suggest a significantly earlier maximum advance on the southern side of the range. Reconstructing the geometry of four glaciers in the Sucha Woda, Pańszczyca, Mlynicka and Velicka valleys allowed determining their equilibrium-line altitudes (ELAs) at 1460, 1460, 1650 and 1700 m asl, respectively. Based on a positive degree-day model, the mass balance and climatic parameter anomaly (temperature and precipitation) has been constrained for LGM I advance. Modeling results indicate slightly different conditions between northern and southern slopes. The N–S ELA gradient finds confirmation in slightly higher temperature (at least 1 °C) or lower precipitation (15%) on the south-facing glaciers during LGM I. The precipitation distribution over the High Tatra Mountains indicates potentially different LGM atmospheric circulation than at the present day, with reduced northwesterly inflow and increased southerly and westerly inflows of moist air masses.     

Coronal Mass Ejections Associated with Slow Long Duration Flares

It is well known that there is a temporal relationship between coronal mass ejections (CMEs) and associated flares. The duration of the acceleration phase is related to the duration of the rise phase of a flare. We investigate CMEs associated with slow long duration events (LDEs), i.e. flares with the long rising phase. We determined the relationships between flares and CMEs and analyzed the CME kinematics in detail. The parameters of the flares (GOES flux, duration of the rising phase) show strong correlations with the CME parameters (velocity, acceleration during main acceleration phase, and duration of the CME acceleration phase). These correlations confirm the strong relation between slow LDEs and CMEs. We also analyzed the relation between the parameters of the CMEs, i.e. a velocity, an acceleration during the main acceleration phase, a duration of the acceleration phase, and a height of a CME at the end of the acceleration phase. The CMEs associated with the slow LDEs are characterized by high velocity during the propagation phase, with the median equal to 1423 km?s^?1. In half of the analyzed cases, the main acceleration was low (a<300 m?s^?2), which suggests that the high velocity is caused by the prolonged acceleration phase (the median for the duration of the acceleration phase is equal 90 minutes). The CMEs were accelerated up to several solar radii (with the median ≈?7 R _⊙), which is much higher than in typical impulsive CMEs. Therefore, slow LDEs may potentially precede extremely strong geomagnetic storms. The analysis of slow LDEs and associated CMEs may give important information for developing more accurate space-weather forecasts, especially for extreme events.     

CN, C2 radicals and dust in Comets Shoemaker-Levy 1991 T2 and P/deVico 1995 S1

The results of the multiaperture photometry of Comet Shoemaker-Levy 1991 T2 in the pre-perihelion and P/deVico in the post-perihelion period with the narrowband CN, C₂ and Blue Continuum (BC) IHW filters are presented. A Haser model of the molecular coma was used for the determination of the parent and daughter scale-lengths and production rates of the radicals. The comets showed some substantial differences between their parent scale-lengths. The CN parent scale-length (at 1.0 AU) was 16×¹⁰³ km for Comet Shoemaker-Levy and 39×¹⁰³ for P/deVico, the C₂ parent scale-lengths were respectively 29×¹⁰³ and 54×¹⁰³ km. Such divergences could be interpreted in the frame of different scenarios of emission of cometary parents, either from a nucleus or from a volume source. The daughter scale-lengths for these comets were quite similar, namely: 306×¹⁰³ and 318×¹⁰³ km for CN and 69×¹⁰³ and 66×¹⁰³ km for C₂. We determined the Afρ parameter for apertures of different radii. A Monte Carlo model of the dust coma was used to obtain the dust ejection velocity. It was of the order of 0.1 km s⁻¹ for both comets. The power index of the distribution of the β-parameter of dust particles (ratio of light pressure to the solar gravitation) was of the order of 3 for C/Shoemaker-Levy and close to 2 for P/deVico. The dependence on heliocentric distance (rh) of the radical and dust production rates for P/deVico in the range of 0.7-1.0 AU was described by the power law function with a power index equal to: 5.55±0.14 for CN, 5.70±0.24 for C₂ and 5.22±0.19 for dust. Relative abundances of the dynamically new Comet Shoemaker-Levy and short-period P/deVico were quite similar with an enhancement of C₂ comparing with standard values taken from A'Hearn et al. (1995).     

EPR and magnetism of the nanostructured natural carbonaceous material shungite

The X-band EPR and magnetic susceptibility in the temperature range 4.2–300 K study of the shungite-I, natural nanostructured material from the deposit of Shunga are reported. Obtained results allow us to assign the EPR signal to conduction electrons, estimate their number, N _P, and evaluate the Pauli paramagnetism contribution to shungite susceptibility. A small occupation (~5%) of the localized nonbonding π states in the zigzag edges of the open-ended graphene-like layers and/or on σ (sp ^2+x ) orbitals in the curved parts of the shungite globules has been also revealed. The observed temperature dependence of the EPR linewidth can be explained by the earlier considered interaction of conduction π electrons with local phonon modes associated with the vibration of peripheral carbon atoms of the open zigzag-type edges and with peripheral carbon atoms cross-linking different nanostructures. The relaxation time T ₂ and diffusion time T _D are found to have comparable values (2.84 × 10⁻⁸ and 1.73 × 10⁻⁸ s at 5.2 K, respectively), and similar dependence on temperature. The magnetic measurements have revealed the suppression of orbital diamagnetism due to small amount of large enough fragments of the graphene layers.     

Petrogenesis of continental mafic dykes from the Izera Complex, Karkonosze-Izera Block (West Sudetes, SW Poland)

The Izera Complex (West Sudetes) contains widespread bodies of metagabbro, metadolerite and amphibolite (the Izera metabasites), and less abundant dykes of weakly altered dolerites, emplaced in a continental setting. The primary magmas of the Izera metabasites were probably formed through adiabatic decompression melting of upwelling asthenosphere (mantle plume) that was associated with the early Palaeozoic fragmentation of Gondwana (initial rift). The rocks are mildly alkaline, transitional-to-tholeiitic basalts and have OIB-like trace element patterns. Trace element modelling reveals that the mafic magmas were generated by variable degrees of partial melting (1–7%) of fertile, garnet-bearing asthenospheric source similar in composition to primitive mantle. Together with an increase in degree of partial melting, the compositional affinity of the magmas and the depth of segregation changed progressively from ca. 70–90 km (mildly alkaline magmas of the metadolerites and amphibolites) to ca. 60–75 km (transitional-to-tholeiitic magmas of the metagabbros). The systematics of incompatible versus compatible element distribution, and major and trace element modelling, indicate that some rocks experienced low-pressure (<5 kbar) differentiation resulting in up to 50% fractionation of clinopyroxene, olivine and minor plagioclase and ilmenite. The genetically distinct weakly altered dolerites are basaltic andesite in composition and possibly related to late- or post-orogenic events in the Karkonosze-Izera Block. These rocks are calc-alkaline, with relatively flat MREE–HREE patterns, enrichment in LREE and other highly incompatible elements relative to primitive mantle, and negative Nb–Ta, Ti, P anomalies. The geochemical features and geochemical modelling, indicate that their primary magmas segregated at depths ≤70 km and were produced by ~2% melting of a metasomatized sublithospheric mantle source presumably containing small amounts of hydrated phases. Although the present study is inconclusive as to the origin of the metasomatic component in the source (? slab-derived fluid/melts, OIB-like alkaline melt percolation of subcontinental lithosphere), the genesis of the Izera basaltic andesites is seemingly related to upwelling of asthenosphere and heat flow triggered by a postulated decoupling of the mantle lithosphere and post-collisional extensional collapse and uplift in the Karkonosze-Izera Block.