Geochemistry of Ordovician Keli Group basalts associated with Besshi-type Cu-Zn deposits from the southern Trondheim and Sulitjelma mining districts of Norway

Besshi-type volcanogenic Cu-Zn deposits in the Scandinavian Caledonides are hosted by Ordovician metabasalts and clastic sediments of the Storen, Fundsjo and Sulitjelma groups. The basalts are transitional between T-MORB and marginal basin tholeiites in composition and are characterised by Nd and Pb isotopic compositions which overlap the more radiogenic values of Lower Palaeozoic MORB. These features, along with the intercalation of the basalts with tuffs and continentally derived sediments, indicate an epicontinental rift or marginal basin origin, possibly analogous to the present Red Sea and Gulf of Aden rifts. This implies the development of a restricted ocean basin in the north of Iapetus between the Laurentian and Baltoscandian microcontinents during the Cambrian and Early Ordovician.     

Biodegradation of polyvinyl alcohol-low linear density polyethylene-blended plastic film by consortium of marine benthic vibrios

Marine bacteria, Vibrio alginolyticus and Vibrio parahemolyticus isolated from sediments were evaluated for their ability as a consortia, to degrade polyvinyl alcohol-low linear density polyethylene (PVA-LLDPE)-blended plastic films in shake flask conditions at 120 rpm at 37 °C over 15 weeks. Results indicated that relatively 20 % decrease in tensile strength of the film could be achieved with 25 and 30 % blend of PVA in the PVA-LLDPE plastic film compared to other ratios. Micrographs obtained with scanning electron microscope showed visible cracks and grooves on the surface of the PVA-LLDPE blend film after 15 weeks of incubation with bacterial consortium. The decrease in tensile strength of the PVA-blended plastic films after treatment and the results of the scanning electron microscopic analysis evidence that the consortium could cause degradation of PVA-LLDPE plastic blends compared to suitable controls. This is the first report on polyvinyl alcohol degrading Vibrio sp. from marine sediments and its application in microbial degradation of polyvinyl alcohol-low linear density polyethylene plastic blends. The study indicated potential of marine benthic vibrios that have novel enzymes and unique characteristics for application in bioremediation and solid waste management particularly in handling synthetic polymers such as PVA-blended plastic films.     

Space-time analysis of the structural pattern of continents

The Earth's stress field is composed of 4 sub-fields that are induced by

1. the gravitational force (impacts, etc; geodynamic theories on the expansion or contraction of the globe);
2. the centrifugal force of the spinning Earth (models on continental drift explaining the equatorial Alpine-Himalayan collisional mountain belt and longitudinally orientated rifts or oceans);
3. thermal convection (plate tectonic model);
4. tidal forces (extended plate tectonic model).

A standard global stress field results from a combination of these four sub-stress-fields. From the existence of six otherwise inexplicable geodynamic phenomena, it has to be concluded that the standard global stress field of the present can only be an instantaneous (still) photograph of a field that constantly migrates eastwards relative to the Earth's continents. This disclosure can be explained with an extended plate tectonic model, in which the Earth's surface is subdivided by the circum-Pacific ring of subduction zones, into a Pacific area and a continental or Pangaea area with intra-Pangaea oceans (Atlantic, Indian Ocean, etc.). The Pangaea area in turn is subdivided into a North Pangaea area and a South Pangaea area. Due to the off-centre rotation of the spinning Earth around the gravitational centre of the Earth-Moon (-Sun) system (tidal forces), the lower mantle, the Pacific basin, area or state (Pacific crust = lower mantle?), the remaining states that together with the Pacific state compose the Wilson Cycle of ocean opening and closing (Rift/Red Sea state, Atlantic state, Pacific state, Collision/Himalayas state), the ocean sequence of which is permanently arranged from E to W through 360° around the globe, and the standard global stress field as an expression of the Wilson Cycle, are constantly displaced eastwards relative to the upper mantle, the continents or the North and South Pangaea areas with Intra-Pangaea oceans, completing one full turn around the globe in 200 to 250 my (principle of hypocycloid gearing). The continents migrate westwards around the globe and around the Pacific basin in the N and S hemispheres, through sequences of plate tectonic settings of the Oceanic or Wilson Cycle that possess distinct regional stress fields as parts of the standars global stress field, or else the continents are subjected to eastward migrating sequences of settings with distinct regional stress fields as parts of the Wilson Cycle/standard global stress field. By rotations and N-S migrations of the individual continents dissected in all directions by groups of parallel structural planes (fracture systems) through the standard global stress field, the orientation of which is aligned with the spinning Earth's axis and equator and that constantly migrates eastwards relative to the continents, the amount and nature of stress (compression, tension, shearing) a given fracture system is subjected to is constantly altered and the tectonic activity may gradually be transferred from the system under consideration to another fracture system, with slightly different strike directions. Every 400 to 500 my or each Pangaea Cycle (two complete W-E/E-W displacements around the globe between the continents/Pangaea areas with Intra-Pangaea Oceans/upper mantle on the one side and the lower mantle/Pacific basin/ sequence of ocean states and local stress fields of the Wilson Cycle and the standard global stress field on the other) the inhomogeneous standard global stress field is reversed in the N-S direction. Any model proposing the long-time existence of extended lineaments or fracture systems that do not end at the margin of the respective continent or at an orogen/suture zone/former continental margin, in the event of being older than the respective orogenesis, but which cross the surrounding ocean or the younger orogen and continue in the neighbouring continents or former independent continents or even encompass the whole globe, and which puts foreward simultaneous tectonic activity along the whole length of such lineament or fracture system and proposes their longevity or permanent existence, contradicts the physical laws that are the foundation of plate tectonics and mobilism.     

P’yŏngyang — ancient and modern —the capital of North Koreangyang — ancient and modern —the capital of North Korea

The capital of the Democratic People’s Republic of Korea (North Korea) is both the oldest and the newest settlement in Korea. The basic concepts in its early urban development made it the model for Korean cities of later ages. In the 6th and 7th century AD P’yôngyang was one of the largest cities in Asia, second only to the imperial capital of China, but it later declined. It partly recovered its former position when it became the capital of North Korea after World War II. Its reconstruction since the Korean War has made it one of the most striking examples of socialist city planning.     

Some examples of the Middle-Triassic Marine transgression in South-Western Mediterranean Europe

In Southwestern Mediterranean Europe (NE Spain, Sardinia and NW Apennines e. g. Monti Pisani and Punta Bianca) the Middle-Triassic transgression on a margin of an intracratonic basin appears to be controlled by the different morphology and tectonic activity of the margin itself. The analysis of some sequences leads to recognize three different kinds of margins:

1. margin with a narrow shelf sloping toward a very shallow restricted basin (Central and Southwestern Sardinia);
2. margin with a broad shelf gently sloping toward a shallow basin (NE Spain, Monti Pisani, NW Sardinia);
3. margin with a narrow shelf and steep slope marked by tectonic and volcanic activity (Punta Bianca).

     

Structure and genesis of the Cubango Megafan in northern Namibia: implications for its hydrogeology

An exploration strategy for groundwater was established and followed in the northern Namibian Cuvelai-Etosha Basin (CEB). The data derived from transient electromagnetics, rotary-drilling, coring and sample investigation were used to refine stratigraphy and hydrostratigraphy, and to develop a 3D map of aquifers within the Cubango Megafan. The results have delineated three major aquifers. The newly found, deep-seated Ohangwena II Aquifer (KOH-2) has the potential of providing significant additional water to the water supply of northern Namibia and Angola. While near-surface aquifers carry predominantly brackish water, freshwater in the deep-seated aquifer is further extended and features good hydraulic properties. To date, only a small part of the hydrogeological potential of arid CEB has been explored and an extension of exploration is needed, including southern Angola. The combination of structural, sedimentological and hydrogeological approaches greatly advanced both the geological and hydrogeological understanding. With regard to the deep-seated aquifer, strict measures need to be applied to ensure that the water in the KOH-2 reservoir is exploited sustainably. Water control areas need to be established to ensure long-term preservation of this newly explored aquifer.     

A Stucture—mineralogical Study of Ringwoodite

The powder XRD analysis of ringwoodite(γ-Fe2SiO4),which was synthesized in a II-stage anvil high-pressure capsule,was made,Its unit-cell parameter was calculated:a=8.219A,After the refinements,for several cycles,of the oxygen parameter x and the occupancy rate of Si in octahedron site,i.e.,the iversion degree u,the final result is R=0.077,when x=0.379A and u=27.5%,with the structural formula (Fe1.725 Si0.275)VI(Si0.725Fe0.275)IV O4 and atomic distances(Fe,Si)VI-O=2.022 A and (Si,Fe)IV-O=1.836A,Meanwhile,the Moessbauer spectroscopic analysis of the sample was conducted and the results obtained are in good agreement with those of X-ray structural analysis ,This paper focuses on the phase transformation and the properties of bonds of α－Fe2SiO4→γ-Fe2SiO4.     

Structural setting and genesis of ore bodies in carbonate rocks in the M.te Atzei-M.te Ega mining area (Sulcis,SW Sardinia)

At least seven different types of ore bodies, with an ore stock of Ba, F, Fe, Pb, Zn, Cu and Sb occur in Paleozoic rocks (Lower-Middle Cambrian and Ordovician) in an ?15 km² area north of the Narcao village (SW Sardinia, Italy). The ore bodies are related both to syngenetic accumulations, and later epigenetic recirculation of the primary ores. In the Lower Cambrian the area studied shows evidence of synsedimentary tectonic instability, probably related to carbonate shelf margin features. The Upper Cambrian is lacking and the transgressive Ordovician sediments cover large areas of the previously gently folded Cambrian rocks (Sardic phase of Caledonian orogenesis). The main Hercynian tectonic phases had a much stronger compressive folding that is mirrored in a sequence of tight folds and upthrusts. The geometric setting resulting from the tectonic frame of the Cambrian and Ordovician sediments must be taken into account to understand the distribution and the genesis of most of the ore bodies.     

Biodegradation of benzo(a)pyrene mediated by catabolic enzymes of bacteria

An investigation was carried out to compare the ability of two bacteria Pseudomonas aeruginosa PSA5 and Rhodococcus sp. NJ2 isolated from petroleum sludge for degradation of benzo(a)pyrene [B(a)P], a HMW PAH compound in MSM. During 25 days of incubation, 50 ppm B(a)P was degraded by 88 and 47 % by P. aeruginosa PSA5 and Rhodococcus sp. NJ2, respectively. Besides, involvement of different catabolic enzymes, that is, salicylate hydroxylase, 2-carboxybenzaldehyde dehydrogenase, catechol 1,2-dioxygenase and catechol 2,3-dioxygenase, was also examined to identify their differential role in B(a)P degradation. Among these enzymes, the highest induction of 2-carboxybenzaldehyde dehydrogenase (773.5 nmol mg^?1 protein) was recorded in P. aeruginosa PSA5, while salicylate hydroxylase was highly expressed (839.6 nmol mg^?1 protein) in Rhodococcus sp. NJ2. Both the bacteria were found biosurfactant (glycolipid) producing, and role of biosurfactant in PAH degradation was also ascertained by reduced surface tension, higher emulsification index and increased cell surface hydrophobicity.     

Modified biomass of Phanerochaete chrysosporium immobilized on luffa sponge for biosorption of hexavalent chromium

Phanerochaete chrysosporium, a white rot basidiomycete, was immobilized over Luffa cylindrica sponge discs, treated with 0.1 N HCl and its potentiality for the removal of hexavalent chromium [Cr(VI)] from water was investigated in both batch and in up-flow fixed-bed bioreactor. The acid treatment of biomass increased the uptake capacity and percentage removal of Cr(VI) from 33.5 to 46.5 mg g^?1 and 67 to 92 %, respectively. Maximum uptake of Cr(VI) was achieved at pH 2, temperature 40 °C after 100 min of contact time. The Cr(VI) sorption on the biomass was better explained by Langmuir isotherm. Thermodynamic studies indicated that the process was spontaneous and endothermic. Sorption kinetic study showed that pseudo-second-order model best correlates the Cr(VI) sorption on the biomass as compare to pseudo-first-order kinetic model. The performance of fixed-bed bioreactor was evaluated at different bed heights (5, 15 and 25 cm) and flow rates (1.66, 4.98 and 8.33 mL min^?1) by using bed depth service time model. Response surface methodology statistical method was applied for optimizing the process parameters. FTIR analysis showed that amino groups were mainly involved in adsorption of Cr(VI).     

Isotopic composition of rain- and groundwater at Mt. Vesuvius: environmental and volcanological implications

The present work reports on the isotopic characterization of rainfall and groundwater at Mt. Vesuvius. Values of δ ¹⁸O, monthly measured on rain samples collected during the period 2002–2004 in a rain-gauge network composed of 10 stations, were compared with meteorological and DEM data. Air temperature, controlled by the local orographic structure, was identified as the main factor influencing rain isotopic composition. Another important role is played by orographic clouds, whose condensation over the top of Mt. Vesuvius is responsible for anomalously high δ ¹⁸O values recorded in rain samples from the summit area of the volcanic edifice. A spatial model of rain isotopic composition, based on a 3D distribution of temperature derived by a 1 × 1 km DEM, was implemented and used for calculating the theoretical isotopic signature of seepage, further compared with data measured in the groundwater monitoring network. The analysis evidenced the role of local meteoric recharge as the main source feeding Mt. Vesuvius aquifers. The unique exception is the Olivella drainage gallery, located on the north-eastern flank of the volcanic edifice, whose isotopic composition is slightly more positive than the one expected for its altitude, likely caused by both evaporation processes and mixing with condensed hydrothermal vapor.     

Temporal and spatial patterns in abundance and diversity of fish assemblages in Elkhorn Slough,California

Assemblages of ichthyofauna of shallow inshore habitats along Californía’s central coast are described in terms of species composition, abundance, and life-style categories. A total of 22,334 fishes from 65 species and 27 families was collected with otter trawls at six sites in the main channel and tidal creeks of Elkhorn Slough, a tidal embayment and seasonal estuary, and two nearshore ocean stations in Monterey Bay during 44 months between August 1974 and June 1980. Greater than 90% of the catch comprised 10 species. The four dominant species,Cymatogaster aggregata, Leptocottus armatus, Phanerodon furcatus, andEmbiotoca jacksoni, occurred during most or all seasons and were classified as residents or partial residents. Several abundant species were marine immigrants that seasonally use the slough as spawning and nursery grounds; this resulted in higher abundance and species richness during summer. Species collected during winter largely were slough residents. Species compsosition and richness varied with distance from the slough entrance. The ocean assemblage was most different, and its similarity to other stations decreased progressively with distance inland and into the tidal creeks. During our study, 5,074 fishes were collected by beach seine in Bennett Slough, a remote shallow marsh basin adjacent to the entrance of Elkhorn Slough. Species richness was relatively low and three euryhaline species accounted for >80% of the total catch. The species assemblage was most similar to those at the tidal creek and most shallow stations of Elkhorn Slough. Resident species numerically dominated assemblages in Bennett Slough and the most inland areas of Elkhorn Slough. The high relative abundance of marine-related fishes (classified as marine, marine immigrant, and partial resident), entering Elkhorn Slough early in life or as spawning adults indicates the importance of this habitat to nearshore fish assemblages.     

Chloritization and its bearing on uranium mineralization in Madyalabodu area,Cuddapah district,Andhra Pradesh

Uranium mineralization in Madyalabodu area, Cuddapah district, Andhra Pradesh, is spatially related to chloritized and brecciated quartzite of the Gulcheru Formation in the immediate vicinity of E-W to ESE-WNW trending basic dyke. Chloritization transgresses the lithological boundaries. Whole-rock geochemical data indicate enrichment of MgO and Al₂O₃ coupled with depletion of SiO₂, Na₂O, K₂O, CaO and TiO₂ in the chlorite-rich zone. Fe₂O₃ and FeO do not vary significantly in the altered and the unaltered zones. Electron Probe Microanalysis (EPMA) data reveal that the chlorites in contact with uranium minerals are enriched in MgO and depleted in FeO than in the others. Considering the petrological evidence, geochemical signature and structural constraints, it appears that chlorite acted more as an adsorbent rather than as a reductant in facilitating uranium mineralization. Uraninite crystallized later from the uranium originally adsorbed on chlorites. Chloritization might also have facilitated mineralization through the generation of nascent hydrogen, H₂S and lowering pH of uranium-bearing solution.     

Simultaneous electrokinetic removal of polycyclic aromatic hydrocarbons and metals from a sediment using mixed enhancing agents

The maintenance of harbor waterways generates large amounts of dredged sediments which are often rich in coexisting organic and inorganic contaminants. Electrokinetic remediation treatments have recently been developed for the simultaneous removal of heavy metals and polycyclic aromatic hydrocarbons (PAHs), using various enhancing agents generally tested sequentially. In this study, different processing fluids were tested, alone or mixed, to improve the decontamination of aged model sediment contaminated with cadmium, lead, chromium, copper, zinc, and five PAHs. Nitric acid (NA) and citric acid (CA) were tested to avoid the formation of an alkaline front into the sediment and favor the metals removal, while an anionic surfactant [sodium dodecyl sulfate (SDS)] and a nonionic surfactant (Tween 20) were tested to solubilize and mobilize PAHs. Processing fluids were circulated under a constant voltage gradient of 1 V cm^?1 for 10–14 days. NA showed an excellent potential to remove metals (76.8–99.9 % removal) and PAHs (70.3–89.7 % removal) in a single run. Besides, the mixture of Tween 20 and CA, more environmental friendly, could be considered as a relatively good processing fluid for the simultaneous removal of metals (10.3–90.8 % removal) and PAHs (53.6–61.6 % removal) from the fine-grained sediment, while SDS mixed to CA was not a good candidate for this purpose (0.1–65 % removal for metals and 34.1–41.0 % removal for PAHs).     

Clicking graphene oxide and Fe3O4 nanoparticles together: an efficient adsorbent to remove dyes from aqueous solutions

Nanohybrid of graphene oxide (GO) and azide-modified Fe₃O₄ nanoparticles (NPs) were fabricated using click reaction. First, Fe₃O₄ NPs were modified by 3-azidopropionic acid. Then, click-coupling of azide-modified Fe₃O₄ NPs with alkyne-functionalized GO was carried out in the presence of CuSO₄·5H₂O and sodium l-ascorbate at room temperature. The attachment of Fe₃O₄ NPs onto the graphene nanosheets was confirmed by Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy, thermogravimetric analysis, energy dispersive X-ray spectrometry and X-ray diffraction spectrometry. As the FTIR spectroscopy and energy dispersive X-ray spectrometry analysis showed, the final magnetic graphene nanosheets were also reduced by sodium ascorbate which is a merit for click-coupling reactions. The specific saturation magnetization of the Fe₃O₄-clicked GO was 44.3 emu g^?1. The synthesized hybrid was used in the adsorption of methylene blue and congo red (CR). The adsorption capacities in the studied concentration range were 109.5 and 98.8 mg g^?1 for methylene blue and CR, respectively.     

The application of a hierarchical Bayesian spatiotemporal model for forecasting the SAA trapped particle flux distribution

We implement a hierarchical Bayesian spatiotemporal (HBST) model to forecast the daily trapped particle flux distribution over the South Atlantic Anomaly (SAA) region. The National Oceanic and Atmospheric Administration (NOAA)-15 data from 1–30 March 2008 with particle energies as >30 keV (mep0e1) and >300 keV (mep0e3) for electrons and 80–240 keV (mep0p2) and > 6900 keV (mep0p6) for protons were used as the model input to forecast the flux values on 31 March 2008. Data were transformed into logarithmic values and gridded in a 5^°×5^° longitude and latitude size to fulfill the modelling precondition. A Monte Carlo Markov chain (MCMC) was then performed to solve the HBST Gaussian Process (GP) model by using the Gibbs sampling method. The result for this model was interpolated by a Kriging technique to achieve the whole distribution figure over the SAA region. Statistical results of the root mean square error (RMSE), mean absolute percentage error (MAPE), and bias (BIAS) showed a good indicator of the HBST method. The statistical validation also indicated the high variability of particle flux values in the SAA core area. The visual validation showed a powerful combination of HBST-GP model with Kriging interpolation technique. The Kriging also produced a good quality of the distribution map of particle flux over the SAA region as indicated by its small variance value. This suggests that the model can be applied in the development of a Low Earth Orbit (LEO)-Equatorial satellite for monitoring trapped particle radiation hazard.     

The accuracy with which coordinates of radio telescopes can be estimated using VLBI observations

Methods for external estimation of the accuracy of geodetic parameters (the coordinates of radio telescopes) based on VLBI observations are discussed. Time series of the distances between radio telescopes (baselines) provide the observational material for the analysis. It is shown that the generally accepted model for estimating the accuracy of geodetic results is based on unjustified assumptions, and does not adequately describe the results of geodetic observations. A more flexible parametrical model is proposed, which takes into account the non-uniformity in the accuracies with which geodetic parameters for different stations can be estimated, and more adequately describes the observational data. The evolution of the Svetloe-Badary and Zelenchuk-Badary baselines in 2007–2012 is analyzed in detail. The Badary VLBI station located near Irkutsk is moving away from the other two stations, located in the European part of Russia, at a rate of 3–4 mm/year.     

Stability conditions of polycyclic aromatic hydrocarbons at high pressures and temperatures

The first results of study of stability of diverse polycyclic aromatic hydrocarbons at around 7 GPa and 773–1073 K are reported. Experiments were carried out in hydraulic multi-anvil presses. The run products after quenching were analyzed using a method of matrix-assisted laser desorption-ionization (MALDI). The formation of polymers of starting matters was determined at 7 GPa and 773–883 K. The polymers are characterized by atomic masses up to 5000 Da, that are multiple by masses of starting matters. At higher temperatures (873–1073 K), the selected PAHs and their polymers become unstable. The decomposition temperature of PAHs and their polymers exclude their stability under Earth’s mantle conditions. The studies could be of great significance for the low-temperature near-surface geodynamics of small and large planetary bodies, which supposedly contain hydrocarbon compounds.     

Sources and history of PAHs in lake sediments from oil-producing and industrial areas,northeast China

Abundance, sources, and historical records of polycyclic aromatic hydrocarbons (PAHs) in sediment cores of three lakes located in northeast China were evaluated. One lake was located in a rural oil field area, one in an industrial urban oil field area, and the third in an urban industrialized area without oil field influence. Cores from each lake were divided into 1-cm sections, dated using ¹³⁷Cs techniques, and 16 priority PAH compounds were measured. Total PAH concentrations were greater in industrial areas than in rural area, regardless of associated oil production. Only petroleum sources of PAHs were identified in lakes near oil fields between 1950s and 1980s, while sources of liquid fossil fuel combustion were persistently identified in the industrial urban lake. From 1990s to 2000s, PAH concentrations, especially high molecular weight PAHs, significantly increased in all lakes, which were consistent with the economic development in China, suggesting a change in energy use from wood burning and petroleum (oil) to liquid fossil fuel combustion. Environmental risk was low to moderate in sediments of the three lakes studied, and increases in high molecular weight PAHs during 1900s–2000s is a concern.     

The problem of rock assimilation by Somma-Vesuvius magma

New chemical and modal analyses are presented of magmatic rocks and pyroxenes nodules from the Somma-Vesuvius volcano and of trachytes from the surrounding area. Geochemical evidence is employed in checking the generally accepted suggestion that magma composition develops from that of trachyte into phonolitic tephrite and finally into tephritic leucitite (vesuvite) by assimilation of dolomite. At the Somma stage of the volcano, phonolitic tephrites (tephritic phonolites) alone have been produced. Vesuvius lavas (tephritic leucitites) are comparatively high in K₂O, CaO, F, Cl, Mn, Cu, Sr and Ba and low in SiO₂ and Nb. The formation of vesuvites by assimilation of dolomitic sedimentary rocks, combined with gravity-separation of early-formed pyroxenes from a trachytic or tephritic magma, is improbable as shown by chemical balances between the respective igneous and sedimentary rocks.