Specific profiles of polybrominated diphenylethers (PBDEs) and polychlorinated biphenyls (PCBs) in fish and tucuxi dolphins from the estuary of Paraíba do Sul River, Southeastern Brazil

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are ubiquitous pollutants in the environment and subject of several studies due to their adverse effects as endocrine disruptors. Despite the concern over widespread distribution of PBDEs even in sparsely populated regions of the world, few studies have reported their occurrence in Brazil. In this study, PBDEs and PCBs levels were measured in selected fish species and dolphins from Paraiba do Sul River, Brazil. BDE 47 and 85 were the predominant congeners. Low chlorinated congeners showed the highest concentrations in fish; however dolphins presented the highest proportion of PCBs 153, followed by 138 and 180. The daily intake of PBDEs and PCBs was estimated for the population of this region. PCB daily intake through consumption of croaker was above the limits set by the Brazilian Ministry of Agriculture, raising great concern over the existence of a source of PCB contamination in Brazil.     

Distribution and significance of C~_(40) alkanes in the extracts of Cretaceous source rocks from the Songliao Basin

Source rock extracts and crude oils from the Songliao Basin were analyzed by high-temperature gas chromatography (HTGC), gas chromatography-mass spectrometry (HTGC-MS) and gas chromatography-isotope ratio-mass spectrometry (GC-IRMS), for high molecular-weight alkanes. The distributions of n-alkanes in the Nenjiang Formation extracts are in the C14―C63 range; a bimodal distribution occurs in the C-21 and C21―40 regions. The C30―C37 n-alkanes are accompanied by C29―C35 hopanes, whereas the high molecular-weight C45―C47 n-alkanes co-occur with abundant isoalkanes, alkylcyclohexanes and alkylcyclopentanes. The high δ 13C values of the n-alkanes and the microscopic maceral compositions indicate a highly diversified organic source input for the Nenjiang Formation source rocks, ranging from aquatic plants, blue alge-bacteria, to land plant material. In contrast, n-alkanes in the rock extracts of the Qingshankou Formation are characterized by a single modal distribution, with relatively low abundances of C29―C35 hopanes, but high molecular-weight isoalkanes, alkylcyclohexanes and alkylcyclopentanes. The relatively low δ 13C values of C22―C44 n-alkanes and organic material compositions indicate that the source rocks in the Qingshankou Formation contain dominantly type I algal organic matter. The relative abundance of C 40 compounds in source rocks changes little at low maturity stage, but decreases drastically at higher maturity levels, with a concurrent reduction in the odd/even carbon predominance. In crude oils, in contrast, the relative abundance of C 40 compounds appears to relate closely with the oil source and oil viscosity.     

Relation Between Deformation Precursors of Fault-Network in the Capital Circle and the Datong Earthquake (M_s6.1)

In this paper,the method of Information Synthesis of Seismogenic System(ISSS)has been used to describe and evaluate the evolution process of self-organization of seismcgenic system in the Capital circle.Through the synthesis of precursory information,the criterion and possible index which characterize the transition of the seismogenic system from steady-state to unsteady-state and then towards the attractor cif a new steady-state have been investigated.The result shows that the synthesis of comprehensive precursor)deformation anomalies of the seismogenic large system(fault-network in the Capital circle),the information synthesis of precursory anomalies of sub-system(a few main fault zones in the Capital circle),and the unweighted or weighted synthesis of anomalous frequencies recognized by the dynamic grey-box method can all raise remarkably the reliability and distinctness of precursory information associated with the Datong Ms 6.1 earthquake.It has provided a criterion and index for evaluation and for     

Geochemical types of natural waters in the interfluve of the Enzor’yakhi and the Yun’yakhi (eastern slope of the Polar Urals)

Natural-water chemistry in the interfluve of the Enzor’yakhi and the Yun’yakhi rivers (the eastern slope of the Polar Urals) is characterized in terms of the ratios of major ions belonging to hydrocarbonate calcium-magnesium and magnesium-calcium chemical types. From the viewpoint of evolution of the water-rock system in the region, five geochemical types of water were identified by the degree of their equilibrium with secondary minerals, reflecting different formation conditions of their chemistry. A specific feature of the region is the formation of waters of organogenic geochemical type, which are considerably enriched by organic matter, determining the specifics of migration of some chemical elements in such waters.     

Geochemical monitoring of the 2002–2003 eruption at Stromboli volcano (Italy): precursory changes in the carbon and helium isotopic composition of fumarole gases and thermal waters

Significant changes in the helium and carbon isotopic composition of shallow thermal waters vs. gas and a crater fumarolic gas have been recorded at Stromboli prior and during the 2002–2003 eruption. The³He/⁴He ratios corrected for air contamination (Rc/Ra), and δ¹³C of fumarolic gases gradually increased from May to November 2002 before the eruption onset. These variations imply early degassing of a gas-rich magma at depth that likely fed both the intense Strombolian activity and small lava overflows recorded during that period. The lava effusion of late December 2002 was shortly preceded by a marked Rc/Ra decrease both in water and fumarolic gases. Comparison of He/CO₂ and CH₄/CO₂ ratios in dissolved gas and with values rules out the Rc/Ra decrease due to an increasing input of radiogenic⁴He. The Rc/Ra decrease is attributed to the He isotope fractionation during rapid magma ascent and degassing. A new uprising of ³He-rich magma probably occurred in January to February 2003, when Rc/Ra ratios displayed the highest values in dissolved gases ever measured before (4.56 Rc/Ra). The increase in He/CO₂ and CH₄/CO₂ ratios and decrease in δ¹³C of dissolved CO₂ was recorded after the 5 April 2003 explosive paroxysm, likely caused by enhanced gas-water interaction inducing CO₂ dissolution. No anomalous Rc/Ra values were recorded in the same period, when usual Strombolian activity gradually resumed.Editorial responsibility: H Shinohara     

Recent Tectonic Deformations and Stresses in the Frontal Part of the Rif Cordillera and the Saïss Basin (Fes and Rabat Regions,Morocco)

—Prerif Ridges are located at the frontal part of the Rif Cordillera, which develops at the Eurasian-African plate boundary. The ridges are formed by recent tectonic structures that also deform foreland basins (Saïss and Gharb basins) and the foreland (Moroccan Meseta). The position of the ridges is the consequence of inversion tectonics undergone in the area. The ENE-WSW trend of the northern edge of the Neogene Saïss basin is determined by the location of Mesozoic basins. Although Prerif ridges probably started to develop since the Early Miocene, the most active deformation phase affecting Pliocene rocks consisted of N-S to NW-SE oriented compression. Striated pebbles show that this compression has prolate stress ellipsoids. The deformation produces southwards vergent folds and NNW-SSE striae on reverse faults at the base of the ridges. The flexure of the Paleozoic basement by the emplacement of the Ridges produced extensional deformation and the development of the Saïss foreland basin. The extension in this basin is oblate and features a well determined NNE-SSW trend near the Ridges, whereas it becomes prolate and pluridirectional near the foreland edge represented by the Rabat region. This part of the Moroccan Meseta, commonly considered to be stable, is deformed by sets of orthogonal joints and faults with short slip that affect up to Quaternary sediments. Southwestward, the Meseta rocks are also deformed by transcurrent faults, which indicate NW-SE and N-S trends of compression. The NW-SE approximation of Eurasia and Africa determines a regional stress field with the same trend of compression. Regional stresses are notably disturbed by the development of the active structures in the Rif, which exhibit alternating trends of compression and extension. The clearest evidence of the relationship between the local deformation and the general plate motion is found at the deformation front of the Cordillera, that is, the Prerif Ridges.     

Comparison of Pb(Ⅱ) and Cd(Ⅱ) micro-interfacial adsorption on fine sediment in the Pearl River Basin,China

The complex micro-interfacial interaction theories of heavy metal ions such as Pb(Ⅱ)and Cd(Ⅱ)adsorption on fine sediment in aqueous solution were not systematically investigated.The aim of this work was to reflect the micro-interfacial adsorption characteristics.Sediment samples were collected from an estuary.The Isothermal and kinetics adsorption experiment were done to acquire the data.Isothermal,kinetics,film diffusion and intraparticle diffusion models were adopted to fit the adsorption experimental data.The results indicated that the Langmuir,Freundlich and Temkin models were suitable for analyzing the isothermal experimental data.The maximum adsorption capacities of Pb(Ⅱ)and Cd(Ⅱ)on the sediment were 1.1377 and 0.9821 mg·g-1,respectively.The qm and KL of the Langmuir model,Kf and nF of the Freundlich model,and b and A of the Temkin model all exhibited a power function relationship with the initial adsorbate concentration.The pseudo-second-order model provided a better fit for the experimental kinetics data compared with the fit of the pseudo-first-order and Elovich models.The pseudo-second-order parameters k2 and qe of Pb(Ⅱ)and qe of Cd(Ⅱ)both had a power function relationship with adsorption time,additionally,the k2 of Cd(Ⅱ)had an exponential function relationship with adsorption time.The liquid-film diffusion parameters kfd of Pb(Ⅱ)and Cd(Ⅱ)were 0.0569 and 0.1806 min
1,respectively.The intraparticle diffusion parameter kid values of Pb(Ⅱ)and Cd(Ⅱ)were 0.0055 mg$g
1$min1/2 and 0.0049 mg$g
1$min1/2,respectively.The physical significance of the model parameters showed that Pb(Ⅱ)adsorption on sediment was stronger than Cd(Ⅱ).The results of this study provided a theoretical reference for the micro-interfacial mechanism of heavy metal ion adsorption on sediment.     

A nested model of the Cariaco Basin (Venezuela): description of the basin’s interior hydrography and interactions with the open ocean

A high-resolution (1/60°), three-dimensional numerical circulation model of the Cariaco Basin (Venezuela) is constructed by nesting the Regional Ocean Modeling System (ROMS) in the 1/12° global Hybrid Coordinate Ocean Model (HYCOM). A new bathymetry, computed by merging DBDB2 data and in situ depth measurements using optimal interpolation, is described. This new bathymetry corrects the depth of the channels that connect the Cariaco Basin with the open ocean and which play a very important role in the basin circulation. Results from a 2004 ROMS hindcast are presented. Observations (temperature, salinity, and currents) are used to validate the model results before using the model to describe the annual cycle of the Cariaco Basin and the interactions between the basin and the open ocean. Two modes of interaction are described, the first being the meanders and eddies that travel westward with the Caribbean Current, and the second being a subsurface eastward current that flows along the north coast of South America. The circulation path within the basin is directly related to the intensity of this current. Both mechanisms described play a role in the ventilation of the basin. The present study is also an example of the feasibility of one of the objectives of GODAE (Global Ocean Data Assimilation Experiment): downscaling from a large-scale model to a regional model. In particular, the nesting ratio of 5 used in this work demonstrates that a high-resolution model can be successfully nested in HYCOM.     

Geochemistry,geochronology, and zircon Hf isotopes of Late Jurassic–Early Cretaceous granitoids in the Xing'an Massif,NE China: Implication for the Late Mesozoic tectonic evolution and crustal growth

This paper presents new zircon U–Pb geochronological, Hf isotopic and whole-rock geochemical data for the granitic plutons in the Xing'an Massif, Northeast China, to constrain the Late Mesozoic tectonic evolution of the Mongol-Okhotsk Ocean and the Paleo-Pacific Ocean. The zircon U–Pb ages indicate that the granitoids emplaced during the Late Jurassic–Early Cretaceous. The granodiorites show an adakitic affinity with high Sr/Y ratios and low Yb (< 1.30 μg/g) contents. The monzogranites exhibit high SiO₂, low MgO contents, enrichment in LILEs (Rb, K, and Th), and depletion in HSFEs (Ta, Nb, Zr, P, and Ti). Petrological and geochemical features of these monzogranites suggest that they are highly fractionated I-type granitoids. In addition, the zircon ε_Hf(t) values and two-stage model ages (T_DM2 ) are in the range of +2.6 to +8.1 and 669–1011 Ma, respectively, indicating that primary magma was generated by partial melting of juvenile lower-crustal materials, and there was a significant crustal growth in the Phanerozoic in the Northeast China. Combined with the coeval granitoids widely exposed in the Xing'an Massif, we conclude that the Late Jurassic magma in Northeast China was generated in an extensional setting related to the closure of the Mongol-Okhotsk Ocean, but the Early Cretaceous magma was related to the subduction of the Paleo-Pacific Plate.     

Comparison of Pb(Ⅱ) and Cd(Ⅱ) micro-interfacial adsorption on ?ne sediment in the Pearl River Basin,China

The complex micro-interfacial interaction theories of heavy metal ions such as Pb(II) and Cd(II)adsorption on fine sediment in aqueous solution were not systematically investigated. The aim of this work was to reflect the micro-interfacial adsorption characteristics. Sediment samples were collected from an estuary. The Isothermal and kinetics adsorption experiment were done to acquire the data.Isothermal, kinetics, film diffusion and intraparticle diffusion models were adopted to fit the adsorption experimental data. The results indicated that the Langmuir, Freundlich and Temkin models were suitable for analyzing the isothermal experimental data. The maximum adsorption capacities of Pb(II) and Cd(II)on the sediment were 1.1377 and 0.9821 mg·g_(-1), respectively. The q_m and K_L of the Langmuir model, K_f and n_F of the Freundlich model, and b and A of the Temkin model all exhibited a power function relationship with the initial adsorbate concentration. The pseudo-second-order model provided a better fit for the experimental kinetics data compared with the fit of the pseudo-first-order and Elovich models.The pseudo-second-order parameters k_2 and q_e of Pb(II) and q_e of Cd(II) both had a power function relationship with adsorption time, additionally, the k_2 of Cd(II) had an exponential function relationship with adsorption time. The liquid-film diffusion parameters k_(fd) of Pb(II) and Cd(II) were 0.0569 and 0.1806 min_(-1), respectively. The intraparticle diffusion parameter k_(id) values of Pb(II) and Cd(II) were0.0055 mg·g_(-1)·min_(1/2) and 0.0049 mg·g_(-1)min_(1/2), respectively. The physical significance of the model parameters showed that Pb(II) adsorption on sediment was stronger than Cd(II). The results of this study provided a theoretical reference for the micro-interfacial mechanism of heavy metal ion adsorption on sediment.     

Study on the Relationship Between Recent Crustal Deformation and the Temporal-Spatial Distribution of Strong Earthquakes ( Ms ≥6.0) in the Sichuan-Yunnan Region

Analysis of deformation data measured across the faults, regional vertical deformation data and GPS measurements in the Sichuan-Yunnan region made since the 1980s permitted us to conclude that the crustal deformation in the region during this period of time was relatively weak and caused the occurrence of earthquakes (Ms≥6.0), which were not distributed along the major boundary active faults in the region after the 1981 I)awu Ms 6.9 earthquake and that the seismic activity is characterized by quasi-clockwise migration. Thus, it follows that earthquake prediction research should be focused on the central part of the Sichuan-Yunnan region in the coming years. Finally, a concept of temporal division of the region into active blocks is suggested and the preliminary result of the division is given in the paper.     

Deterministic Variability of the Ionosphere on the Eve of Strong (M ≥ 6) Earthquakes in the Regions of Greece and Italy According to Long-Term Measurements Data

Geomagnetism and Aeronomy - Abstract—Specific features of the variation in the electron concentration in the ionosphere in front of strong (M ≥ 6) earthquakes in the most seismically...     

Observations of pre-midnight 5-m irregularities in the equatorial F region over São Luís,Brazil: Solar-flux dependence and seasonal variations

The statistics of pre-midnight 5-m irregularities in the equatorial F region over São Luís is presented. The data set ranges from October 2001 to December 2008 and covers maximum solar-flux-to-minimum solar flux epoch. The variabilities in irregularity parameters, namely, height and time of their appearance in the radar echoes, with solar-flux variation are presented. The seasonal variations (combined over all years, irrespective of solar-flux) of occurrence of irregularities, occurrence of bottom-type layer (or bottom-side irregularities without plume) and bottom-side/topside plume (or bottom-side irregularities with plume) are presented. The largest occurrences of bottom-side irregularities without plume and with plume are found on April (equinox) and December (summer) months respectively. The ambient ionospheric conditions namely prereversal evening vertical drift, bottom-side density gradient and off-equatorial E region conductivity are inferred using digisonde measurements during April 2002 and December 2002. Based on these conditions and recent studies on gravity wave climatology over Brazil, it is suggested that shear in zonal plasma drift and low gravity wave activity may account for less occurrence of plume during April as compared to December months. This suggestion is quantified using numerical simulation model of collisional-interchange instability (CII) and plasma bubble.     

Hydrochemical Regime in Riverine Aqual Complexes: Case Study of the Small Il’d River (Rybinsk Reservoir Basin)

Water Resources - The results of studying the space and time dynamics of the hydrochemical regime in discrete aquatic areas of a riverine aquatic–territorial complex of a small river over...     

SLA–chlorophyll-a variability and covariability in the Algero-Provençal Basin (1997–2007) through combined use of EOF and wavelet analysis of satellite data

Data reduction and signal decomposition techniques have been applied to a large bio-physical remotely sensed dataset covering the decade 1997–2007. The aim was the estimation of the spatial (basin and sub-basin scales) and temporal (seasonal and interannual) variability of sea level anomalies and chlorophyll-a concentration in the Algero-Provençal Basin, as well as the study of their covariability. Empirical orthogonal functions, wavelet analysis, singular value decomposition and correlation maps have been successfully used to individuate the patterns of (co)variability of the investigated fields. The seasonal variability of the phytoplanktonic biomass is divided in two distinct modes, timewise and spacewise separated. Positive interannual events are related to anomalies in 1999 and 2005, while the main (negative) anomaly is that of summer 2003, associated to the European 2003 heatwave. The analysis of the sea level anomalies shows a minimum in the formation of anticyclonic Algerian eddies during that period. The largest anticorrelation between sea level anomalies and phytoplanktonic biomass is found in the central zone of the basin, suggesting a clear biological response to the shoaling/deepening of the isopycnae and so to the nutrient injection into the euphotic layer. The analysis suggests that the driver of the variability of the nutricline depth in this central area is the displacement (seasonal) of the North Balearic Front and the formation/action of the frontal eddies.     

Late stage thermal history of the Songliao Basin and its tectonic implications: Evidence from apatite fission track (AFT) analyses

Apatite Fission Track (AFT) data from the Songliao Basin indicates that the late stage tectonic movements in the Songliao Basin have zoning in space and episodes in time. The late stage tectonic movements started from the east part of the basin and migrated westward. AFT ages in the east part of the basin are older than those in the west part of the basin, suggesting that the uplift occurred earlier in the east than in the west. The denudation thickness in the east part of the basin is significantly greater than that in the centre and west. The thermal history evolved two episodes of rapid cooling and subsequent slow cooling processes. Age-depth relationship derived from the AFT data indicates a four-episode denudation history. Further Monte Carlo random simulation of the AFT data reveals the four changing points of the thermal evolution at 65 Ma, 43.5 Ma, 28 Ma and 15 Ma, respectively. The uplifting and denudation rates from different episodes of evolution are proportional to the plate convergence rate. Based on the above analyses and the regional geologic background, it is concluded that the late stage thermal events in the Songliao Basin are the far field response to the subduction of the Pacific Plate under the Eurasian Plate. The first episode of the rapid cooling probably started at the end of the Nenjiang Formation, climaxed at the end of the Cretaceous and ceased at the Late Eocene. The subsequent slow cooling lasts another 15 Ma. The first episode of the evolution is the far field response to the major episode of the Yanshan Movement and subsequent series of the tectonic reorganization, especially the directional change of the Pacific Movement and also the subduction of the Indian Plate underneath the Eurasian Plate. While the second episode of the evolution is the far field response to the extension and closure of the Sea of Japan. Extension led to the migration and converging of the mantle heat flow to the Sea of Japan and resulted in the rapid cooling of the Songliao Basin.     

Fluctuations of floods of the River Morava (Czech Republic) in the 1691–2009 period: interactions of natural and anthropogenic factors

Abstract

Floods from the middle part of the River Morava (eastern Czech Republic) are considered over the course of the past three centuries, the study being based on data derived from documentary evidence (1691–1880), measured peak water stages, H_k (1881–1920) and peak discharges, Q_k (1916–2009), evaluated with respect to their N-year return period (H_N and Q_N ). Changes in land use and water management (water reservoirs, channel modifications) are discussed, as are factors influencing runoff conditions in the Morava catchment. Decadal synthesis of flood series identifies the highest flood activity in the decades of 1911–1920 and 1961–1970 (11 floods each), 1831–1840, 1891–1900, 1901–1910 and 1931–1940 (10 floods each). Uncertainty in this series is related to some incompleteness of documentary data in the pre-1881 period. Very low flood frequency occurred in the 1990s–2000s, although the most disastrous floods were recorded in this particular period (July 1997 at Q ₁₀₀ and March/April 2006 at Q ₂₀–Q ₅₀). Changes in flood frequency correspond partly to long-term changes in temperature and precipitation patterns.

Citation Brázdil, R., ?ezní?ková, L., Valá?ek, H., Havlí?ek, M., Dobrovolný, P., Soukalová, E., ?ehánek, T. & Skokanová, H. (2011) Fluctuations of floods of the River Morava (Czech Republic) in the 1691–2009 period: interactions of natural and anthropogenic factors. Hydrol. Sci. J. 56(3), 468–485.     

Mn content of reservoir calcite cement: A novel inorganic geotracer of secondary petroleum migration in the tectonically complex Junggar Basin (NW China)

Electronic probe microanalysis(EPMA) results of reservoir calcite cement from fourteen core samples in the Junggar Basin show that Mn-content varies largely between different samples from below the detect limitation to 4.14%,while it displays a generally good correlation with oil-gas shows.This,therefore,likely indicates that concentration of the Mn-content of the calcite cement has a close rela-tion to the intensity of petroleum fluid charging during hydrocarbon secondary migration.In order to assess this hypothesis,oxygen and strontium isotopic measurements on sixteen calcite veins host in source sequences were carried out to investigate the feature of the oil-source petroleum fluid.Analytical results imply that during hydrocarbon generation and migration,deep hot fluid has dissolved volcanic minerals interlined between mudstone source rocks.As Mn is a kind of typical trace element enriched in volcanic rocks,it is reasonable to conclude that the petroleum fluid formed in the source sequences would be Mn-rich.Consequently,calcite cements precipitated from such Mn-rich petroleum fluid would be Mn-rich accordingly.Due to the geologic chromatographic effect during migration along reservoir rocks,the decreasing of the Mn-content of the reservoir calcite cements indicates the migration direction.Then,this novel geotracer was further successfully applied in the study of hydrocarbon migration in the Junggar Basin in combination with organic geochemical analyses during the hydrocarbon migration.The Mn content of the reservoir calcite cement appears promising as a novel inorganic geotracer for the petroleum migration.This paper represents a search for novel indicators of secondary petroleum migration in tectonically complex basins based on fundamentals of the reservoir fluid-rock interactions.     

Identification of sweet spots in shale-type and siltstone-type “shale oil systems”: A case study of the Chang 7 Member in Ordos Basin

Mid-high maturity shale oil is the most realistic field for the scale breakthrough of terrestrial shale oil production in China. Generally, three deficiencies hinder shale oil development in China: heavy oil density, small sweet spot areas, and poor distribution continuity. Thus, identifying the “sweet spots” in shale oil reservoirs is critical for the efficient exploration and development of terrestrial shale oil. This study targets the siltstone type(Class-Ⅱ shale oil) and pure shale type(Clas...     

~(40)Ar/~(39)Ar and Rb-Sr isochron dating of the gold deposits on northern margin of the Jiaolai Basin,Shandong,China

The Shandong Peninsula (Jiaodong) is a very important gold producer of China. Over ten large and super-large quartz-vein type and shear zone-type gold deposits related to Yanshannian granite intrusions have been exploited in the northern part of the Jiaod…