Evaluating Copper Behavior in Urban Surface Waters Under Anthropic Influence. A Case Study from the Igua?u River, Brazil

The goal of this work was to investigate the changes in copper behavior in Igua?u River, a body of water strongly affected by urban inputs. This work was carried out in a subtropical Brazilian watershed suffering with high loads of raw sewage discharges from the Metropolitan Region of Curitiba. A comparison between sampling sites located upstream and downstream from the urban region revealed that human inputs are able to modify the water chemistry of the river in a short distance basis, that is, approximately nine miles. Probably, the most important alterations were the creation of an anaerobic environment as well as the enhancement of humic-coated suspended solids. These two aspects were determinant to explain the high concentrations observed for particulate copper (57% of total recoverable copper) and dissolved copper sulfide species (13%) in the water column. Copper in the sediment was also higher in the downstream site, probably due to the sedimentation of the Cu-enriched particles. However, copper sulfides at the bottom sediment may also be a potential source for the metal in the water column due to the creation of anaerobic conditions in both compartments. Labile copper concentration was not affected by the changes in water chemistry. Despite the fact that sewage discharges motivate the enhancement of organic matter, but not the increase in potential complexing agents, additional ligands such as chloride, carbonates, and anthropogenic dissolved organic ligands can be now computed as a part of the labile fraction.     

Thermal expansion and high temperature structure evolution of zoisite by single-crystal X-ray and neutron diffraction

The thermo-elastic behaviour and the temperature-induced structure evolution of a natural Fe-free zoisite have been investigated by in situ single-crystal X-ray and neutron diffraction. Neither discontinuities in volume expansion nor changes in symmetry have been observed up to 1,023 K. Zoisite shows a negative thermal expansion along [100] at T > 700 K, while a continuous positive expansion occurs on the (100) plane. Two different regimes in the anisotropic thermal behaviour of zoisite can be distinguished (i.e. at T < 700 K and T > 700 K), corresponding to an increase in the volumetric thermal expansion at T > 700 K. The structure evolution with temperature has been described by a series of X-ray and neutron refinements at different temperatures. In particular, the M(3) polyhedra show a significant octahedral flattening and expansion in the equatorial plane with T. All [SiO₄] tetrahedra show a regularization with increasing T. The neutron refinements show no change in the configuration of the hydrogen bonding at least up to 873 K. The effects of the T-induced main deformation mechanisms on the anisotropic elastic behaviour of zoisite are discussed. A comparison with the thermal behaviour of epidote has been carried out.     

Heavy metals pollution in the soil of an irregular urban settlement built on a former dumpsite in the city of Tijuana, Mexico

The aim of this study was to evaluate soil pollution by heavy metals in an irregular settlement built on a dumpsite. The soil samples were analyzed for Cd, Cr, Cu, Pb and Ni. None of the concentrations found for the heavy metals analyzed were higher than the established Mexican official standards for contaminated soils. The mean concentrations found for the analyzed metals were as follows: 1.4 mg kg⁻¹ for Cd, 4.7 in mg kg⁻¹ for Cr, 304 mg kg⁻¹ for Cu, 74 mg kg⁻¹ for Pb and 6 mg kg⁻¹ for Ni. The results of the geoacummulation index values show that the site was very polluted with Cu and Pb (class 7), polluted to strongly polluted with Ni (class 4); moderately polluted to polluted with Cd (class 3), and moderately polluted with Cr (class 1). The correlation analysis shows a high correlation between Pb and Cu (r ² = 0.98), which would be explained if the main source of the polluting heavy metals was the result of electrical wire burning to recover Copper. Principal component analysis shows three principal components. The first main component (PC1) encompasses Cr, Cd, Pb and Cu. These heavy metals most likely have their origins from the open burning of municipal solid waste, tires and wire. The other two components are encompassed by Cr (PC2) and Ni (PC3). The sources of these pollutants are more likely related to the corrosion of junk metal objects and automobile use.     

Paleoenvironmental and geoarchaeological reconstruction from late Holocene slope records (Lower Huerva Valley,Ebro Basin,NE Spain)

Slope deposits in semiarid regions are known to be very sensitive environments, especially those that occurred during the minor fluctuations of the late Holocene. In this paper we analyse Holocene colluvium genesis, composition, and paleoenvironmental meaning through the study of slope deposits in NE Spain. Two cumulative slope stages are described during this period. In the study area, both slope accumulations are superimposed and this has enabled an excellent preservation of the aggregative sequence and the paleosols corresponding to stabilisation stages. ¹⁴C and TL dating, as well as archaeological remains, provide considerable chronological precision for this sequence. The origin of the accumulation of the lower unit is placed around 4295–4083 cal yr BP/2346–2134 cal yr BC (late Chalcolithic) and it developed until the Iron Age in a cooler and wetter climate (Cold Iron Age). Under favourable conditions, a soil A-horizon was formed on top of this unit. A new slope accumulation was formed during the Little Ice Age. Within the slope two morphogenetic periods ending with A-horizons are distinguished and related with two main cold–wet climatic events. The study of these slopes provides a great amount of data for the paleoenvironmental and geoarchaeological reconstruction of the late Holocene in NE Spain.     

An environmental snapshot of the Bølling interstadial in Southern Iberia

The Bølling–Allerød interstadial is the closest warm time period to the Holocene. The study of the climate variability during this most recent warm scenario provides a natural record of potential environmental changes related with global temperature variations. Little is known about this interstadial in the Southern Iberian Peninsula. Therefore, the exceptional climatic record of the Otiñar paleo-lake (ca. 14.5–14.0 cal ka BP), provides environmental information about the first part of this interstadial (Bølling) in this key region. Although the studied high-resolution isotopic record point to almost invariant hydrological conditions in the paleo-lake, with little change in the carbon budget and important limestone dissolution, the pollen record shows an increase in forest species that can be interpreted as a warming trend and an increase in humidity during the Bølling in the area. This record is one of the few continental archives that show this climatic trend in Southern Iberia, agreeing with many other regional records from the western Mediterranean. This does not agree with higher latitude records that show an opposite trend. This opposite pattern in precipitation between the western Mediterranean and more northern latitudes could be explained by a persistent and increasing negative NAO mode during the Bølling in this area.     

Observed seasonal and intraseasonal variability of the East India Coastal Current on the continental slope

We present data from three acoustic Doppler current profilers (ADCPs) moored off Cuddalore (12^°N), Kakinada (16.5^°N), and Gopalpur (19^°N) on the continental slope of the western Bay of Bengal and one mooring on the slope of the northern bay (89^°E, 19^°N; referred to as being located at Paradip). The data were collected during May 2009 to March 2013 and the observations show that the seasonal cycle, which includes the annual cycle, the semi-annual cycle, and a peak around 120 days, dominates the observed variability of the East India Coastal Current (EICC). Spectral analysis suggests that the 120-day peak dominates the seasonal variability at Paradip and is strong at Gopalpur and Kakinada. The annual cycle is coherent along the western boundary of the bay, i.e., the east coast of India, but with significant phase differences between moorings. At the semi-annual and 120-day periods, the alongshore coherence is weaker. Intraseasonal variability is weaker than the seasonal cycle, particularly at Cuddalore and Paradip, and it exhibits seasonality: the strongest intraseasonal variation is during spring (February–April). Peaks around 12 and 20–22 days are also seen at Gopalpur, Kakinada, and Cuddalore. A striking feature of the currents is the upward phase propagation, but there are also instances when phase propagates downward. The much lower vertical phase speed in the top ～100 m at Cuddalore leads to a distinct undercurrent at this location; at other locations, the undercurrent, though it exists often, is not as striking. During spring, however, the EICC tends to flow poleward (eastward) at Cuddalore, Kakinada, and Gopalpur (Paradip) over the top ～300 m, which is the maximum depth to which observations were made. The cross-shore component of the EICC is much weaker than the alongshore component at Cuddalore and, except for a few bursts during spring, at Kakinada and Gopalpur. It is only at Paradip, on the slope of the northern boundary, that significant cross-shore flows are seen during spring and the summer monsoon (June–August) and these flows are seen to be associated with eddy-like circulations in the altimeter data. We use the ADCP data to validate popular current data products like OSCAR (Ocean Surface Currents Analyses Real-time), ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II), and GODAS (Global Ocean Data Assimilation System). The OSCAR currents at Paradip match the observed currents well, but the correlation is much weaker at the other three locations. Both ECCO2 and GODAS fair poorly, particularly the latter because its variability in this boundary-current regime is extremely weak. Though it performs badly at Paradip, ECCO2 does capture the observed variability on occasions at the other locations.     

Assessment of subsurface structural elements around greater Cairo by using integrated geophysical tools

Geophysical techniques such as gravity, magnetic and seismology are perfect tools for detecting subsurface structures of local, regional as well as of global scales. The study of the earthquake records can be used for differentiating the active and non-active fault elements. In the current study, more than 2,200 land magnetic stations have been measured using two proton magnetometers. The data are corrected for diurnal variations and then reduced by the International Geomagnetic Reference Field. The corrected data have been interpreted by different techniques after filtering the data to separate shallow sources (basaltic sheet) from the deep sources (basement complex). Both Euler deconvolution and 3-D magnetic modeling were carried out. The results of interpretation indicate that the depth to the upper surface of basaltic sheet ranges from <10 to 600 m, depth to the lower surface ranges from 60 to 750 m, while the thickness of the basaltic sheet varies from <10 to 450 m. Moreover, gravity measurements are conducted at 2,250 stations using a CG-3 gravimeter. The measured values are corrected to construct a Bouger anomaly map. The least squares technique is then applied for regional–residual separation. The third order of least squares is found to be the most suitable to separate the residual anomalies from the regional one. The resultant third-order residual gravity map is used to delineate the structural fault systems of different characteristic trends. The trends show an NW–SE trend parallel to that of Gulf of Suez, an NE–SW trend parallel to the Gulf of Aqaba and an E–W trend parallel to that of the Mediterranean Sea. Taking seismological records into consideration, it is found that most of the 24 earthquake events recorded in the study area are located on fault elements. This gives an indication that the delineated fault elements are active.     

On the depth to anomaly estimation using Karous and Hjelt filter in VLF-EM data

The Karous and Hjelt filter has been long time used as a qualitative interpretation of VLF-EM data. It is derived directly from the concept of magnetic fields associated with the current flow in the subsurface and resulted in a 2-D cross section showing the current density distribution at different depths. Practically, as the distance between measuring points increases, the total depth of the 2-D current density distribution section increases. Theoretically, the common guide to estimate the depth of penetration of an electromagnetic wave is the skin depth, which depends on the frequency of the electromagnetic wave and the conductivity of the host geological material, regardless of the distance interval between measuring points. Accordingly, the accuracy of the Karous and Hjelt filter regarding depth estimation of the anomaly is tested in this study. We proposed a conductive anomaly in a definite dimension and depth. The response of this conductive body is calculated as in-phase and out-of-phase synthetic VLF data via forward modeling. The synthetic VLF data is filtered by the Karous and Hjelt filter at 1, 5, and10 m of interval distance between measuring points. The present study showed that the Karous and Hjelt filter is characterized by a large degree of accuracy in depth estimation.     

Review of the El Soplao Amber Outcrop,Early Cretaceous of Cantabria,Spain

<正>El Soplao outcrop,an Early Cretaceous amber deposit recently discovered in northern Spain (Cantabria),has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far.Relevant data provided herein for biogeochemistry of the amber,palynology,taphonomy and arthropod bioinclusions complement those previously published.This set of data suggests at least two botanical sources for the amber of El Soplao deposit.The first(type A amber)strongly supports a source related to Cheirolepidiaceae,and the second(type B amber)shows non-specific conifer biomarkers.Comparison of molecular composition of type A amber with Frenelopsis leaves(Cheirolepidiaceae)strongly suggests a biochemical affinity and a common botanical origin.A preliminary palynological study indicates a regional high taxonomical diversity,mainly of pteridophyte spores and gymnosperm pollen grains.According to the preliminary palynological data,the region was inhabited by conifer forests adapted to a dry season under a subtropical climate.The abundant charcoalified wood associated with the amber in the same beds is evidence of paleofires that most likely promoted both the resin production and an intensive erosion of the litter,and subsequent great accumulation of amber plus plant cuticles.In addition,for the first time in the fossil record, charcoalified plant fibers as bioinclusions in amber are reported.Other relevant taphonomic data are the exceptional presence of serpulids and bryozoans on the surfaces of some amber pieces indicating both a long exposure on marine or brackish-water and a mixed assemblage of amber.Lastly,new findings of insect bioinclusions,some of them uncommon in the fossil record or showing remarkable adaptations,are reported.In conclusion,a documented scenario for the origin of the El Soplao amber outcrop is provided.