Cumulative effects of land use on fish metrics in different types of running waters in Austria

The catchment land-use composition of 249 fish sampling sites in Austrian running waters revealed effects on the biological integrity. Beyond correlative analysis, we investigated (1) which land-use category had the strongest effect on fish, (2) whether metrics of functional fish guilds reacted differently, (3) whether there were cumulative effects of land-use categories, and (4) whether effects varied in strength across river types. We fed 5 land-use categories into regression trees to predict the European Fish Index or fish metric of intolerant species (mainly Salmo trutta fario). Agriculture and urbanisation were the best predictors and indicated significant effects at levels of >23.3 and >2%, respectively. Model performance was R ² = 0.15 with the Fish Index and R ² = 0.46 with intolerant species. The tree structure showed a cumulative effect from agriculture and urbanisation. For the intolerant species metric, a combination of high percentages for agriculture and urbanisation was related to moderate status, whereas <7.3% agriculture were related to good status, although urbanisation was higher than 1.8%. Headwater river types showed stronger responses to land use than river types of lower gradient and turned out to be more sensitive to urbanisation than agriculture.     

Protocol for Quantitative Detection of Elemental Sulfur and Polysulfide Zero-Valent Sulfur Distribution in Natural Aquatic Samples

A HPLC-based protocol has been developed for the determination of zero-valent sulfur (ZVS) speciation, including solid, colloidal elemental sulfur and individual inorganic polysulfides in natural aquatic samples. The protocol includes four experimental procedures: (1) determination of polysulfide speciation by rapid single-phase derivatisation with methyl trifluoromethanesulfonate; (2) determination of the sum of polysulfide and colloidal sulfur by reaction with hydrogen cyanide (cyanolysis); (3) determination of total zero-valent sulfur by treatment with zinc chloride followed by extraction with chloroform; and (4) chromatographic determination of polythionates without sample pre-treatment. With proper sampling and preservation techniques in the field or on board ship, this combination of methods allowed the quantitative determination of: (a) individual polysulfide species; (b) dispersed colloidal sulfur; (c) dispersed solid elemental sulfur; and (d) tetra-, penta- and hexathionates. With minor modification, the method could be expanded to include other polythionates. Sixteen various wet chemical and liquid chromatographic methods were tested on nine synthetic reference samples (including solid elemental sulfur, colloidal elemental sulfur, inorganic polysulfides and polythionates) to establish the optimal protocol. The protocol was further evaluated by analysing the zero-valent sulfur content in microbially-produced sulfur and in sulfur from two natural samples of sulfide-rich seawater from tidal flats pools of the Wadden Sea (Germany).     

The You Yangs batholith in Southeastern Australia,the sources of its magmas and inferences for local crustal architecture

The 365-Ma You Yangs batholith is a mainly I-type monzogranitic body, containing rocks with both clinopyroxene and hornblende, but with a 2–2.5?km-wide rim of S-type rocks. In places, the margins of the intrusion wedge out laterally. A laccolithic shape may explain there being only low-grade contact metamorphism of the Ordovician metasedimentary wall rocks. The chemical and isotopic characteristics of the granitic rocks suggest that the magmas formed by partial melting of a source that contained some meta-igneous rocks but was dominated by chemically immature metasedimentary types, to impart an evolved Sr isotope signature (⁸⁷Sr/⁸⁶Sr_t?=?0.70877–0.71066 for the main monzogranitic rocks), combined with relatively non-radiogenic εNd_t (–2.4 to –1.9). Crystal fractionation played little role in shaping the compositions of the granitic magmas, with the main variations interpreted to be source-inherited. Igneous-textured microgranular enclaves (IMEs) are prominent in the monzogranitic rocks. The IMEs probably had an ultimate enriched-mantle source, and their magmas did not mix significantly with the crustally derived granitic host magmas. The characteristics of the monzogranitic rocks hosting the enclaves suggest the possibility that an unrecognised metasediment-dominated terrane of ancient arc crust may be present beneath the Bendigo Zone.     

Quaternary clay mineralogy in the northern South China Sea (ODP Site 1146) —— Implications for oceanic current transport and East Asian monsoon evolution

The East Asian monsoon system is a thermodynamic atmospheric circulation induced by the different potential heating between the 揥estern Pacific Warm Pool?(WPWP) and the Asian continent. The circulation patterns dominate seasonal patterns of winds, preci…     

Anthropogenic noble-metal enrichment of topsoil in the Monchegorsk area, Kola Peninsula, northwest Russia

Eight catchments, an area of 15 to 35 km², have been studied within an ecogeochemical mapping programme in the western Kola Peninsula and contiguous parts of Finland and Norway. Three catchments, one northeast of Zapolyarniy (1) and two, 5 and 25 km south of Monchegorsk (2 and 4) show high levels of deposition of heavy metals, especially nickel (Ni) and copper (Cu), related to the metallurgical industry in these cities. Twenty-five topsoil samples, from sites evenly distributed over catchment 2, have mean contents of Ni and Cu 1 to 2 orders of magnitude higher than both C-horizon samples from the same sites and topsoil samples from catchment 4, providing strong evidence for the anthropogenic origin of the heavy metals. The same samples show geometric mean total contents for the noble metals analysed of: 1.4 μg/kg rhodium (Rh), 49.6 μg/kg platinum (Pt), 187.6 μg/kg palladium (Pd) and 9.5 μg/kg gold (Au). The pattern of concentration of the noble metals mirrors that found in published averages for ore from the Talnakh mineralizations in the Noril'sk province, though 1–2 orders of magnitude lower. This also clearly shows that the noble-metal contents of the topsoil are anthropogenic, and suggests that they emanate from the plants in Monchegorsk at an early stage in treatment of the ore, probably as a minor component of Ni-Cu rich particles. The noble-metal geochemistry of the topsoil in the other catchments also reflects the nature of the ore being processed at the plants nearby.     

Stability of phlogopite-quartz and sanidine-quartz: A model for melting in the lower crust

The melting of phlogopite-quartz and sanidine-quartz under vapor-absent conditions and in the presence of H₂O-CO₂ vapor have been determined from 5–20 kbar. In the lower crust (P=6–10 kbar), phlogopite + quartz melts incongruently to enstatite + liquid at temperatures as low as 710° C in the presence of H₂O. When the activity of water is sufficiently reduced by addition of CO₂, phlogopite + quartz undergoes a dehydration reaction to enstatite + sanidine + vapor, for example at 790±10° C, 5 kbar, with \(X_{H_2 O}^V\) =0.35. In the absence of vapor, phlogopite + quartz is stable up to a maximum temperature of 900° C in the crust; at higher temperatures this assemblage melts incongruently to enstatite + sanidine + liquid. The melting of sanidine-quartz in the presence of H₂O-CO₂ vapor shows marked topological differences from melting in the system albite-H₂O-CO₂, and as a result, apparent activity coefficients for water calculated from sanidine-quartz H₂O-CO₂ are less than those calculated from albite-H₂O-CO₂ by up to a factor of five. These data shed light on anatexis in the lower crust, but uncertainties related to ordering of Al and Si in natural and synthetic micas forestall a more rigorous analysis. Nevertheless, maximum temperatures for some granulite terranes can be established.     

Element contents in mountain birch leaves,bark and wood under different anthropogenic and geogenic conditions

Forty samples each of leaves, bark and wood of mountain birch (Betula pubescens EHRH.) were collected along a 120 km long south–north transect running through Norway’s largest city, Oslo. Concentrations of 26 chemical elements (Ag, As, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti and Zn) as well as loss on ignition for the three sample materials are reported. By far the highest concentrations of most elements appear in the leaves. Prominent exceptions are Au and Pb, both of which are enriched in wood, indicating the importance of root-uptake, and As which is enriched in bark. Bedrock lithology, ore occurrences, soil pH and urban contamination all have a visible influence on the element concentrations in mountain birch leaves, bark and wood. It is often impossible to differentiate between all the factors that can influence element concentrations in the three sample materials. Mountain birch bark shows the strongest anthropogenic impact of the city of Oslo for dust-related elements (Fe, La, Ti) and Sb. Even in mountain birch bark the influence of the city on element concentrations is no longer discernible from the background variation at a distance of less than 20 km from Oslo centre. Compared to terrestrial moss, mountain birch appears to be of little value as a biomonitor for urban contamination.     

Combining machine-learning topic models and spatiotemporal analysis of social media data for disaster footprint and damage assessment

Current disaster management procedures to cope with human and economic losses and to manage a disaster’s aftermath suffer from a number of shortcomings like high temporal lags or limited temporal and spatial resolution. This paper presents an approach to analyze social media posts to assess the footprint of and the damage caused by natural disasters through combining machine-learning techniques (Latent Dirichlet Allocation) for semantic information extraction with spatial and temporal analysis (local spatial autocorrelation) for hot spot detection. Our results demonstrate that earthquake footprints can be reliably and accurately identified in our use case. More, a number of relevant semantic topics can be automatically identified without a priori knowledge, revealing clearly differing temporal and spatial signatures. Furthermore, we are able to generate a damage map that indicates where significant losses have occurred. The validation of our results using statistical measures, complemented by the official earthquake footprint by US Geological Survey and the results of the HAZUS loss model, shows that our approach produces valid and reliable outputs. Thus, our approach may improve current disaster management procedures through generating a new and unseen information layer in near real time.     

How deceptive are microstructures in granitic rocks? Answers from integrated physical theory,phase equilibrium,and direct observations

In this contribution, we address the vexed question of the extent to which microstructures in granitic rocks reflect their igneous histories or have been masked by later events. The previous works have tended to address the problem either using theoretical or modelling considerations, or by interpretation of observed microstructures. Here, we use an approach that integrates the theory of microstructural development and the results of experimental phase-equilibrium studies with direct observation of natural examples on a variety of scales. We show that the predictions of the theoretical and experimental approaches agree perfectly with the mesoscopic and microscopic evidence from granitic rocks themselves. Our conclusion is that although, in many cases, granitic rock microstructures have been modified by near-solidus reactions and crystallisation, in the absence of tectonic deformation the fundamental elements of their igneous heritage remain intact. This means that it is perfectly in order to infer aspects of crystallisation sequences, magmatic reactions, and magma flow through careful microstructural observations. Thus, our answer to the question of how deceptive granitic textures are is, in most instances, ‘not very’. However, some undeformed plutons have undergone fluid-driven alteration, and others have been affected by contact metamorphism. Thus, each case should be examined on its own merits.