Iron-manganese concretions are common in upper sola of Alfisols in the Inner Bluegrass Region of Kentucky. Their nature and quantities appear to be related to the fluctuation of seasonal perched water tables above clayey argillic horizons. This study was conducted to examine changes in the macro-and micromorphology, chemistry and mineralogy of concretions as a function of size, color and soil depth. Total Mn and Fe contents increased, while SiO2 decreased with concretion size. Black concretions contained higher Mn, while brown concretions were higher in Fe. Crystalline Mn- and Fe-oxides fractionated with a sequential extraction procedure increased, but amorphous Mn and Fe decreased with concretion size. Goethite was the only crystalline Fe oxide mineral identified by X-ray diffraction (XRD) analysis. Manganese oxide minerals were very difficult to detect due to the diffuse nature of their XRD peaks and poor crystallinity. Examination of soil thin sections showed concretions of soil horizons overlying restrictive clayey layers to exhibit differentiated fabrics, sharp external boundaries and generally spherical shapes. Concretions found within clayey restrictive layers or above lithic interfaces usually had less structural organization, softer matrices and diffuse external boundaries due to longer term saturated conditions. Scanning electron microscopy (SEM) examinations suggested that the concretionary matrix, in spite of its density, has numerous cavities and an extensive micropore system within which dissolved plasmic Fe and Mn can diffuse and precipitate.

Loess paleoenvironmental reconstructions on regional to supra-regional scales have recently gained much attention. Geochemistry comparisons in relation to reference datasets, such as the Upper Continental Crust (UCC) data, have furthered our understanding of the climatic and geomorphological conditions under which terrestrial sites have developed. However, UCC data differs from loess, thereby obscuring important features, and the existing “average loess” datasets also are not sufficient for modern investigations.

In this study, we examine the youngest Polish loess (L1LL1 = MIS 2, ca. 26–15 ka) for its suitability as a new, loess-focused reference dataset. Eighty-nine samples from seven sites were analyzed, using inductively coupled plasma spectrometry. The loess had assumedly been homogenized during transportation and/or sedimentary recycling (LaN/SmN = 3.34–4.06, median 3.78; Eu/Eu* = 0.46–0.66, median 0.55; GdN/YbN = 1.08–1.49, median 1.26), and weakly affected by pre- or post-depositional weathering (CIA = 53.64–69.12, median 57.69). The statistically significant differences between sites in elemental medians were mostly conditioned by variations in grain size and in the “fresh” to “re-deposited” sediment ratio. Nonetheless, the overall geochemical composition homogeneity provided a basis for the estimation of Polish Median Loess (PML) data, as determined for 41 chemical elements. When used, PML data highlight differences between loess regions in Europe, thereby providing a tool for cross-continental comparisons.

Antarctica is a natural research laboratory thanks to its unique climate, geography, flora and fauna. The conservation of Antarctica's environment is monitored through the Madrid Protocol; however, there are local pollution problems associated with human activities such as research and tourism; in particular, there are negative impacts on air quality from the use of fossil fuels. In this work, we studied for the first time the magnetic and elemental characteristics of the lichen Usnea aurantiaco-atra (Jacq.) Bory collected during different years and from various sites in King George Island, Antarctic Peninsula, as well as some samples of its supporting substrate, for long-term monitoring of atmospheric pollution. Several anthropogenic elements (Ni, Pb, Mo, Cd and Zn) have been identified on sites close to human activities, but also on sites far from them. We found that magnetic proxies from U. aurantiaco-atra samples show a spatial correlation with human influence (scientific bases or airstrips). We observed a correlation between magnetic parameters and Ni and, to a lesser extent, with Cr, Co, V and Ag. The results suggest that by using these magnetic and elemental techniques it is possible to implement monitoring with the lichen U. aurantiaco-atra as a bioindicator for some elements of anthropogenic origin.

Arid central Asia plays an important role in global climate dynamics, but large uncertainties remain in our understanding of the region's hydroclimate variability during the Late Quaternary. Here we present a new, high-resolution record of lacustrine sediment grain-size and element chemistry from Ebinur Lake, which was used to infer lake conditions and related climate changes in the study region between ca. 39.2 and 3.6 ka. End-member modeling analysis of grain-size data and PCA of elemental data show that lake level fluctuated dramatically from 39.2 to 34.0 ka. Subsequently, Ebinur Lake experienced a high stand from 34.0 to 28.0 ka, under humid climate conditions. The subsequent period, from 28.0 to 12.0 ka, was characterized by lake regression under dry climate conditions, whereas afterward (12.0–3.6 ka), considerably higher lake levels and humid conditions again prevailed. Millennial-scale abrupt climate changes, such as Heinrich events (H3 and H1) and the Younger Dryas, which are documented in the North Atlantic region, are also detected in the sediment record from Ebinur Lake. Comparisons with other sediment records from arid central Asia generally support the claim that climate change in this region was influenced mainly by variations in North Atlantic sea surface temperatures, through the westerlies.

Slags sourced from a derelict zinc–lead–copper–silver–tungsten mine were examined for their bulk elemental composition and mineralogy. pH, oxidation–reduction potential, and the leachability of selected elements (sulphur, calcium, iron, copper, zinc, and lead) were assessed during a 130-day deionised water extraction conducted under oxic conditions. Slags were rich in silicon, iron, copper, zinc, and lead, hosted within minerals including quartz (SiO2), goethite [FeO(OH)], augite [Ca(Mg,AI,Fe)Si2O6], and lead (Pb0). Leachates from the slags increased in analyte concentration throughout the 130-day experiment, with iron, copper, zinc, and lead attaining >5 mg l−1 in some samples. These findings indicate that this pyrometallurgical waste should not be considered environmentally inert, as leachates emanating from them in the field might pose a significant risk to the environment.

pCO2/pH perturbation experiments were carried out under two different pCO2 levels to evaluate effects of CO2-driven ocean acidification on semi-continuous cultures of the marine diatom Skeletonema pseudocostatum CSA48. Under higher pCO2/lowered pH conditions, our results showed that CO2-driven acidification had no significant impact on growth rate, chlorophyll-a, cellular abundance, gross photosynthesis, dark respiration, particulate organic carbon and particulate organic nitrogen between CO2-treatments, suggesting that S. pseudocostatum is adapted to tolerate changes of ~0.5 units of pH under high pCO2 conditions. However, dissolved organic carbon (DOC) concentration and DOC/POC ratio were significantly higher at high pCO2, indicating that a greater partitioning of organic carbon into the DOC pool was stimulated by high CO2/low pH conditions. Total fatty acids (FAs) were significantly higher under low pCO2 conditions. The composition of FAs changed from low to high pCO2, with an increase in the concentration of saturated and a reduction of monounsaturated FAs. Polyunsaturated FAs did not show significant differences between pCO2 treatments. Our results lead to the conclusion that the balance between negative or null effect on S. pseudocostatum ecophysiology upon low pH/high pCO2 conditions constitute an important factor to be considered in order to evaluate the global effect of rising atmospheric CO2 on primary productivity in coastal ocean. We found a significant decrease in total FAs, however no indications were found for a detrimental effect of ocean acidification on the nutritional quality in terms of essential fatty acids.

This paper considers the early copper and copper-alloy metallurgy of the entire Alpine region. It introduces a new approach to the interpretation of chemical composition data sets, which has been applied to a comprehensive regional database for the first time. The Alpine Chalcolithic and Early Bronze Age each have distinctive patterns of metal use, which can be interpreted through changes in mining, social choice, and major landscape features such as watersheds and river systems. Interestingly, the Alpine range does not act as a north-south barrier, as major differences in composition tend to appear on an east-west axis. Central among these is the prevalence of tin-bronze in the western Alps compared to the east. This ‘tin-line’ is discussed in terms of metal flow through the region and evidence for a deeply rooted geographical division that runs through much of Alpine prehistory.

Nutrient subsidies from one ecosystem to another serve a critical link among ecosystems. The transfer of materials across the terrestrial-to-marine boundary is considered to be driven by hydrological connectivity, but animal movement can provide another pathway for nutrient transfers. In two separate studies we assessed the role mammals (bats and kangaroos) play in alleviating nutrient limitation in mangrove forests in Australia. At Lizard Island, we measured tree growth and foliar elemental and isotopic composition of trees growing within and outside a large flying fox roost. In Western Australia, we measured foliar elemental and isotopic composition of trees within two forests frequented by kangaroos that feed in spinifex grasslands and shelter in the shade of the mangroves. We compared those with mangroves from adjacent forests that are not frequented by kangaroos. We show that at both locations, the mangrove forest receives terrestrial nutrient subsidies through animal movement. At Lizard Island dominant mangrove species were significantly enriched in nitrogen within the bat roost, as evidenced by higher foliar N concentrations (by up to 150%), N:P and N:C ratios in trees within the roost compared with trees outside the roost. The isotopic signature of foliar N was significantly enriched in 15N by 1–3‰ within the roost, further suggesting that the source of the N enrichment was the bat roost. Growth rates of mangroves within the roost were nearly six times higher than trees outside the roost. In the arid coast of Western Australia, we show elevated foliar 15N abundance of up to 3‰ in mangroves where kangaroos shelter relative to trees where they do not. Thus, this study presents two examples for mammalian herbivore mediated localized transport of nutrients from terrestrial to marine ecosystems, consequently affecting mangrove tree growth, productivity and forest structure.

Solid particles in snow deposits, sampled in mining and Pb-processing area of Žerjav, Slovenia, have been investigated using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Identified particles were classified as geogenic–anthropogenic, anthropogenic, and secondary weathering products. Geogenic–anthropogenic particles were represented by scarce Zn- and Pb-bearing ore minerals, originating from mine waste deposit. The most important anthropogenic metal-bearing particles in snow were Pb-, Sb- and Sn-bearing oxides and sulphides. The morphology of these particles showed that they formed at temperatures above their melting points. They were most abundant in snow sampled closest to the Pb-processing plant and least abundant in snow taken farthest from the plant, thus indicating that Pb processing was their predominant source between the last snowfall and the time of sampling. SEM/EDS analysis showed that Sb and Sn contents in these anthropogenic phases were higher and more variable than in natural Pb-bearing ore minerals. The most important secondary weathering products were Pb- and Zn-containing Fe-oxy-hydroxides whose elemental composition and morphology indicated that they mostly resulted from oxidation of metal-bearing sulphides emitted from the Pb-processing plant. This study demonstrated the importance of single particle analysis using SEM/EDS for differentiation between various sources of metals in the environment.

The influence of temperature on larval survival and development was studied in the edible crab, Cancer pagurus, from a population off the island of Helgoland, North Sea. In rearing experiments conducted at six different temperatures (6°, 10°, 14°, 15°, 18° and 24°C), zoeal development was only completed at 14° and 15°C. Instar duration of the Zoea I was negatively correlated with temperature. A model relating larval body mass to temperature and developmental time suggests that successful larval development is possible within a narrow temperature range (14° ± 3°C) only. This temperature optimum coincides with the highest citrate synthase activity found at 14°C. A comparison for intraspecific variability among freshly hatched zoeae from different females (CW 13–17 cm, N = 8) revealed that both body mass and elemental composition varied significantly. Initial larval dry weight ranged from 12.1 to 17.9 μg/individual, the carbon content from 4.6 to 5.8 μg/individual, nitrogen from 1.1 to 1.3 μg/individual, and the C:N ratio from 4.1 to 4.4. A narrow larval temperature tolerance range of C. pagurus as well as the indication of intraspecific variability in female energy allocation into eggs may indicate a potential vulnerability of this species to climate change. Large-scale studies on the ecological and physiological resilience potential of this commercially fished predator are needed.

Evaporation rate and subsequent exposure to humid air affect the surface morphology and composition of cesium iodide (CsI) films and, in turn, their photoemissive efficiency when used as photocathodes. The surface morphology and elemental composition of 300-nm-thick CsI films grown at two different rates (1 nm/s and 0.04 nm/s), both freshly evaporated and after 24-h exposure to humid air were investigated by means of atomic force microscopy and scanning electron microscopy/electron diffraction spectroscopy. The CsI film freshly evaporated at a slow rate exhibited a granular surface presenting circular holes or craters where the CsI material was moved from the center to the boundaries. After 24-h exposure to humid air, this film coalesced in large grain showing a marked increase of surface roughness. Conversely, the CsI film grown at a fast rate mostly retained its original surface uniformity and homogeneity with no presence of holes and craters after 24-h exposure to humid air. Further, surface roughness and average peak height decreased, but the surface coalesced in large grains spaced by small fractures where the CsI coverage was almost lost. In conclusion, the films grown at a fast evaporation rate were affected by 24-h exposure to humid air less than those grown at a slow rate, and are thus expected to possess a greater long-term stability.

The elemental composition of Ceratium hirundinella was determined in mixed phytoplankton samples collected over a 2-month period (late June to early September 1995). Electron probe X-ray microanalysis spectra of single cells routinely showed clear peaks of monovalent (Na, K) and divalent (Mg, Ca) cations, plus Si, P, S and Cl. Considerable variation in elemental concentrations occurred both within and between samples (20 cells). The overall ratio of monovalent to divalent cations was relatively constant at about 1.3. Intracellular concentrations of anions/cations and electronegative/electropositive elements were significantly correlated in most samples, suggesting a controlled internal balance of these ionic groups. Correlation analysis of elemental concentrations revealed clear patterns of statistical association within individual samples, with significant positive correlations between particular pairs of elements (Mg–P, K–Cl and K–P). Some pairs of highly correlated elements (particularly Mg–P) occurred in defined ratios throughout the samples, while others (e.g. K–Cl, Na–Mg) were variable. Factor analysis showed that elemental associations were determined by two Principal Factors in most samples, possibly related to insoluble and soluble components of cells. Decrease in the level of available P in lake water was associated with a sharp decrease in the intracellular P concentration and the concentration of other correlated elements. The estimated C/P ratio markedly differed from the classical (Redfield) value at times of low P availability. The concentration of P in cells of Ceratium was approximately 104 times greater than in the surrounding water medium (total P) compared with values of 102–103 for K.