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Viktor Kalinchuk, Evgeny Lopatnikov, Anatoly Astakhov
Gaseous elemental mercury (Hg0) is a prolific and persistent contaminant in the atmosphere. Atmospheric concentrations of Hg0 were determined from 17 September to 7 October 2015 in the northwest Sea of Japan aboard the Russian research vessel Professor Gagarinsky. Simultaneous measurements of Hg0 concentrations were performed 2 m and 20 m above the sea surface using automatic Hg0 analysers RA-915M and RA-915+, respectively. Concentrations ranged from 0.3 to 25.9 ng/m3 (n = 5207) and from 0.3 to 27.8 ng/m3 (n = 4415), with medians of 1...
December 6, 2017: Environmental Pollution
Gavin M Mudd, Simon M Jowitt, Timothy T Werner
The platinum group elements (PGEs) are used in many technologies and products in modern society, especially auto-catalysts, chemical process catalysts and specialty alloys, yet supply is dominated by South Africa. This leads PGEs to be assessed as 'critical metals', signalling concern about the likelihood and consequences of social, environmental and economic impacts from disruptions to supply. In order to better understand the global PGE situation, this paper presents a comprehensive global assessment of PGE reserves and resources and the key mining trends which can affect supply...
December 6, 2017: Science of the Total Environment
W P Schellart
Subduction along the western margin of South America has been active since the Jurassic, but Andean orogeny started in the middle Cretaceous and was preceded by backarc extension in the Jurassic-Early Cretaceous. The timing and sequence of these events has remained unexplained. Here I present a four-dimensional buoyancy-driven whole-mantle subduction model implying that the ~200 Myr geological evolution can be attributed to sinking of a wide slab into a layered mantle, where upper-mantle wide-slab subduction causes backarc extension, while whole-mantle (upper+lower) wide-slab subduction drives Andean orogeny...
December 8, 2017: Nature Communications
Daniel Roush, Estelle Couradeau, Brandon Guida, Susanne Neuer, Ferran Garcia-Pichel
Anoxygenic phototrophic bacteria (APBs) occur in a wide range of aquatic habitats, from hot springs to freshwater lakes and intertidal microbial mats. Here we report the discovery of a novel niche for APBs: endoliths within marine littoral carbonates. In a study of 40 locations around Isla de Mona, Puerto Rico, and Menorca, Spain, 16S rRNA high-throughput sequencing of endolithic community DNA revealed the presence of abundant phylotypes potentially belonging to well-known APB clades. An ad hoc phylogenetic classification of these sequences allowed us to refine the assignments more stringently...
December 8, 2017: Applied and Environmental Microbiology
O De Giglio, G Caggiano, F Apollonio, A Marzella, S Brigida, E Ranieri, L Lucentini, V F Uricchio, M T Montagna
In most regions of the world, safeguarding groundwater resources is a serious issue, particularly in coastal areas where groundwater is the main water source for drinking, irrigation and industry. Water availability depends on climate, topography and geology. The aim of this paper is to evaluate aquifer recharge as a possible strategy to relieve water resource scarcity. Natural aquifer recharge is defined as the downward flow of water reaching the water table, increasing the groundwater reservoir. Hydro-meteorological factors (rainfall, evapotranspiration and runoff) may alter natural recharge processes...
January 2018: Annali di Igiene: Medicina Preventiva e di Comunità
Mukan Ji, Chris Greening, Inka Vanwonterghem, Carlo R Carere, Sean K Bay, Jason A Steen, Kate Montgomery, Thomas Lines, John Beardall, Josie van Dorst, Ian Snape, Matthew B Stott, Philip Hugenholtz, Belinda C Ferrari
Cultivation-independent surveys have shown that the desert soils of Antarctica harbour surprisingly rich microbial communities. Given that phototroph abundance varies across these Antarctic soils, an enduring question is what supports life in those communities with low photosynthetic capacity. Here we provide evidence that atmospheric trace gases are the primary energy sources of two Antarctic surface soil communities. We reconstructed 23 draft genomes from metagenomic reads, including genomes from the candidate bacterial phyla WPS-2 and AD3...
December 6, 2017: Nature
J Miot, S Bernard, M Bourreau, F Guyot, A Kish
Burial is generally detrimental to the preservation of biological signals. It has often been assumed that (bio)mineral-encrusted microorganisms are more resistant to burial-induced degradation than non-encrusted ones over geological timescales. For the present study, we submitted Sulfolobus acidocaldarius experimentally encrusted by amorphous Fe phosphates to constrained temperature conditions (150 °C) under pressure for 1 to 5 days, thereby simulating burial-induced processes. We document the molecular and mineralogical evolution of these assemblages down to the sub-micrometer scale using X-ray diffraction, scanning and transmission electron microscopies and synchrotron-based X-ray absorption near edge structure spectroscopy at the carbon K-edge...
December 5, 2017: Scientific Reports
Faten Telahigue, Belgacem Agoubi, Fayza Souid, Adel Kharroubi
The present study integrates hydrogeological, hydrochemical and radiogenic data of groundwater samples taken from the Plio-Quaternary unconfined aquifer of Jerba Island, southeastern Tunisia, in order to interpret the spatial variations of the groundwater quality and identify the main hydrogeochemical factors responsible for the high ion concentrations and radon-222 content in the groundwater analysed. Thirty-nine groundwater samples were collected from open wells widespread on the island. Physical parameters (EC, pH, TDS and T °) were measured, major ions (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, NO3- and HCO3-) were analysed and 222Rn concentrations were determined using a RAD7-H2O...
December 1, 2017: Journal of Environmental Radioactivity
Michael A Kipp, Eva E Stüeken
Phosphorus sets the pace of marine biological productivity on geological time scales. Recent estimates of Precambrian phosphorus levels suggest a severe deficit of this macronutrient, with the depletion attributed to scavenging by iron minerals. We propose that the size of the marine phosphorus reservoir was instead constrained by muted liberation of phosphorus during the remineralization of biomass. In the modern ocean, most biomass-bound phosphorus gets aerobically recycled; but a dearth of oxidizing power in Earth's early oceans would have limited the stoichiometric capacity for remineralization, particularly during the Archean...
November 2017: Science Advances
Maria Beatrice Magnani, Michael L Blanpied, Heather R DeShon, Matthew J Hornbach
To assess whether recent seismicity is induced by human activity or is of natural origin, we analyze fault displacements on high-resolution seismic reflection profiles for two regions in the central United States (CUS): the Fort Worth Basin (FWB) of Texas and the northern Mississippi embayment (NME). Since 2009, earthquake activity in the CUS has increased markedly, and numerous publications suggest that this increase is primarily due to induced earthquakes caused by deep-well injection of wastewater, both flowback water from hydrofracturing operations and produced water accompanying hydrocarbon production...
November 2017: Science Advances
Ryoji Wani
The latitudinal distributions in Devonian-Cretaceous ammonoids were analyzed at the genus level, and were compared with the hatchling sizes (i.e., ammonitella diameters) and the geological durations. The results show that (1) length of temporal ranges of ammonoids effected broader ranges of fossil distribution and paleobiogeography of ammonoids, and (2) the hatchling size was not related to the geographical range of fossil distribution of ammonoids. Reducing the influence of geological duration in this analysis implies that hatchling size was one of the controlling factors that determined the distribution of ammonoid habitats at any given period in time: ammonoids with smaller hatchling sizes tended to have broader ammonoid habitat ranges...
2017: PeerJ
Chonghong Zhang, Jiejie Lv, Fuchun Li, Xuelin Li
Calcite spherulites have been observed in many laboratory experiments with different bacteria, and spherulitic growth has received much interest in mineralogy research. However, the nucleation and growth mechanism, as well as geological significance of calcite spherulites in solution with bacteria is still unclear. Herein, spherulites composed of an amorphous core, a Mg-calcite body and an organic film were precipitated by the Curvibacter lanceolatus HJ-1 bacterial strain in a solution with a molar Mg/Ca ratio of 3...
December 4, 2017: Microscopy and Microanalysis
Elsa A Cousins, Courtney J Murren
PREMISE OF THE STUDY: Studies on phenotypic plasticity and plasticity of integration have uncovered functionally linked modules of aboveground traits and seedlings of Arabidopsis thaliana, but we lack details about belowground variation in adult plants. Functional modules can be comprised of additional suites of traits that respond to environmental variation. We assessed whether shoot and root responses to nutrient environments in adult A. thaliana were predictable from seedling traits or population-specific geologic soil characteristics at the site of origin...
December 1, 2017: American Journal of Botany
J M LaManna, D S Hussey, E Baltic, D L Jacobson
Dual mode tomography using neutrons and X-rays offers the potential of improved estimation of the composition of a sample from the complementary interaction of the two probes with the sample. We have developed a simultaneous neutron and 90 keV X-ray tomography system that is well suited to the study of porous media systems such as fuel cells, concrete, unconventional reservoir geologies, limestones, and other geological media. We present the characteristic performance of both the neutron and X-ray modalities...
November 2017: Review of Scientific Instruments
Joana Estevens, Paulo Rocha, João P Boto, Pedro G Lind
We model non-stationary volume-price distributions with a log-normal distribution and collect the time series of its two parameters. The time series of the two parameters are shown to be stationary and Markov-like and consequently can be modelled with Langevin equations, which are derived directly from their series of values. Having the evolution equations of the log-normal parameters, we reconstruct the statistics of the first moments of volume-price distributions which fit well the empirical data. Finally, the proposed framework is general enough to study other non-stationary stochastic variables in other research fields, namely, biology, medicine, and geology...
November 2017: Chaos
Helen Crabbe, Tony Fletcher, Rebecca Close, Michael J Watts, E Louise Ander, Pauline L Smedley, Neville Q Verlander, Martin Gregory, Daniel R S Middleton, David A Polya, Mike Studden, Giovanni S Leonardi
Approximately one million people in the UK are served by private water supplies (PWS) where main municipal water supply system connection is not practical or where PWS is the preferred option. Chronic exposure to contaminants in PWS may have adverse effects on health. South West England is an area with elevated arsenic concentrations in groundwater and over 9000 domestic dwellings here are supplied by PWS. There remains uncertainty as to the extent of the population exposed to arsenic (As), and the factors predicting such exposure...
December 1, 2017: International Journal of Environmental Research and Public Health
Luke A Parry, Fiann Smithwick, Klara K Nordén, Evan T Saitta, Jesus Lozano-Fernandez, Alastair R Tanner, Jean-Bernard Caron, Gregory D Edgecombe, Derek E G Briggs, Jakob Vinther
Exceptionally preserved fossils are the product of complex interplays of biological and geological processes including burial, autolysis and microbial decay, authigenic mineralization, diagenesis, metamorphism, and finally weathering and exhumation. Determining which tissues are preserved and how biases affect their preservation pathways is important for interpreting fossils in phylogenetic, ecological, and evolutionary frameworks. Although laboratory decay experiments reveal important aspects of fossilization, applying the results directly to the interpretation of exceptionally preserved fossils may overlook the impact of other key processes that remove or preserve morphological information...
November 29, 2017: BioEssays: News and Reviews in Molecular, Cellular and Developmental Biology
Xiaolin Wang, Alexander W A Kellner, Shunxing Jiang, Xin Cheng, Qiang Wang, Yingxia Ma, Yahefujiang Paidoula, Taissa Rodrigues, He Chen, Juliana M Sayão, Ning Li, Jialiang Zhang, Renan A M Bantim, Xi Meng, Xinjun Zhang, Rui Qiu, Zhonghe Zhou
Fossil eggs and embryos that provide unique information about the reproduction and early growth of vertebrates are exceedingly rare, particularly for pterosaurs. Here we report on hundreds of three-dimensional (3D) eggs of the species Hamipterus tianshanensis from a Lower Cretaceous site in China, 16 of which contain embryonic remains. Computed tomography scanning, osteohistology, and micropreparation reveal that some bones lack extensive ossification in potentially late-term embryos, suggesting that hatchlings might have been flightless and less precocious than previously assumed...
December 1, 2017: Science
Krishna Kumar Yadav, Neha Gupta, Vinit Kumar, Shakeel Ahmad Khan, Amit Kumar
Fluoride contamination of groundwater is a serious problem in several countries of the world because of the intake of excessive fluoride caused by the drinking of the contaminated groundwater. Geological and anthropogenic factors are responsible for the contamination of groundwater with fluoride. Excess amounts of fluoride in potable water may cause irreversible demineralisation of bone and tooth tissues, a condition called fluorosis, and long-term damage to the brain, liver, thyroid, and kidney. There has long been a need for fluoride removal from potable water to make it safe for human use...
November 27, 2017: Environment International
Patricia L Clay, Ray Burgess, Henner Busemann, Lorraine Ruzié-Hamilton, Bastian Joachim, James M D Day, Christopher J Ballentine
Volatile element delivery and retention played a fundamental part in Earth's formation and subsequent chemical differentiation. The heavy halogens-chlorine (Cl), bromine (Br) and iodine (I)-are key tracers of accretionary processes owing to their high volatility and incompatibility, but have low abundances in most geological and planetary materials. However, noble gas proxy isotopes produced during neutron irradiation provide a high-sensitivity tool for the determination of heavy halogen abundances. Using such isotopes, here we show that Cl, Br and I abundances in carbonaceous, enstatite, Rumuruti and primitive ordinary chondrites are about 6 times, 9 times and 15-37 times lower, respectively, than previously reported and usually accepted estimates...
November 29, 2017: Nature
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