Profiling of dissolved organic compounds in the oil sands region using complimentary liquid–liquid extraction and ultrahigh resolution Fourier transform mass spectrometry     

Yi Yi  Jun Han  S. Jean Birks  Christoph H. Borchers  John J. Gibson 《Environmental Earth Sciences》2017,76(24):828

Understanding and characterizing organics in aquatic environments is a great challenge for environmental monitoring, especially for the oil sands industry due to the complexity and potential toxicity of dissolved organics in water. To date, significant efforts have been made in investigating the toxicity of naphthenic acids, although other compounds may also contribute to the toxicity of oil sands process-affected water (OSPW). Here, we present a case study showing a systematic approach for profiling the organic composition of OSPW and environmental water samples by concentrating and separating dissolved organics through complementary liquid–liquid extractions followed by positive- or negative-ion mode ultrahigh resolution mass detection. Our comparative investigation shows clear differences in the composition of dissolved organics (homologues particularly) not only between OSPW samples and environmental water samples, but also differences among oil sands operators. Sulfur-containing compounds (especially the SO _n classes) appear to have great potential to be used for evaluating the impact of OSPW, while our understanding of oxygen-only containing compounds should not be limited to O₂ (i.e., classic naphthenic acids), but rather can be broadened to include many other compound classes (for instance O _n , n = 1–9). Systematic profiling of water samples should be more widely implemented for monitoring the origin and transport of organics in aquatic ecosystems of the oil sands development region, northeastern Alberta, Canada.  相似文献   

Estimating greenhouse gas emissions from cattle raising in Brazil     

Mercedes M. C. Bustamante  Carlos A. Nobre  Roberto Smeraldi  Ana P. D. Aguiar  Luis G. Barioni  Laerte G. Ferreira  Karla Longo  Peter May  Alexandre S. Pinto  Jean P. H. B. Ometto 《Climatic change》2012,115(3-4):559-577

The study estimated, for the first time, the greenhouse gas emissions associated with cattle raising in Brazil, focusing on the period from 2003 to 2008 and the three principal sources: 1) portion of deforestation resulting in pasture establishment and subsequent burning of felled vegetation; 2) pasture burning; and 3) bovine enteric fermentation. Deforestation for pasture establishment was only considered for the Amazon and Cerrado. Emissions from pasture burning and enteric fermentation were accounted for the entire country. The consolidated emissions estimate lies between approximately 813 Mt CO₂eq in 2008 (smallest value) and approximately 1,090 Mt CO₂eq in 2003 (greatest value). The total emissions associated with Amazon cattle ranching ranged from 499 to 775 Mt CO₂eq, that of the Cerrado from 229 to 231 Mt CO₂eq, and that of the rest of the country between 84 and 87 Mt CO₂eq. The full set of emissions originating from cattle raising is responsible for approximately half of all Brazilian emissions (estimated to be approximately 1,055 Mt CO₂eq in 2005), even without considering cattle related sources not explicitly estimated in this study, such as energy use for transport and refrigeration along the beef and derivatives supply chain. The potential for reduction of greenhouse gas emissions offered by the Brazilian cattle industry is very high and might constitute Brazil’s most important opportunity for emissions mitigation. The study offers a series of policy recommendations for mitigation that can be implemented by public and private administrators at a low cost relative to other greenhouse gas reduction options.  相似文献   

Distinguishing between fault scarps and shorelines: the question of the nature of the Kahrizak,North Rey and South Rey features in the Tehran plain (Iran)   总被引：1，自引：0，他引：1  

Hamid Nazari  Jean‐François Ritz  Reza Salamati  Alireza Shahidi  Hasan Habibi  Manuchehr Ghorashi  Alireza Karimi Bavandpur 《地学学报》2010,22(3):227-237

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Formation and preservation of pedogenic carbonates in South India, links with paleo-monsoon and pedological conditions: Clues from Sr isotopes, U-Th series and REEs     

Aurélie Violette  Jean Riotte  Jean-Jacques Braun  Priscia Oliva  Jean-Christophe Marechal  M. Sekhar  Catherine Jeandel  Jonathan Prunier  Laurent Barbiero  Bernard Dupre 《Geochimica et cosmochimica acta》2010,74(24):7059-7085

The influence of the pedogenic and climatic contexts on the formation and preservation of pedogenic carbonates in a climosequence in the Western Ghats (Karnataka Plateau, South West India) has been studied. Along the climosequence, the current mean annual rainfall (MAR) varies within a 80 km transect from 6000 mm at the edge of the Plateau to 500 mm inland. Pedogenic carbonates occur in the MAR range of 500-1200 mm. In the semi-arid zone (MAR: 500-900 mm), carbonates occur (i) as thick hardpan calcretes on pediment slopes and (ii) as nodular horizons in polygenic black soils (i.e. vertisols). In the sub-humid zone (MAR: 900-1500 mm), pedogenic carbonates are disseminated in the black soil matrices either as loose, irregular and friable nodules of millimetric size or as indurated botryoidal nodules of centimetric to pluricentimetric size. They also occur at the top layers of the saprolite either as disseminated pluricentimetric indurated nodules or carbonate-cemented lumps of centimetric to decimetric size.Chemical and isotopic (⁸⁷Sr/⁸⁶Sr) compositions of the carbonate fraction were determined after leaching with 0.25 N HCl. The corresponding residual fractions containing both primary minerals and authigenic clays were digested separately and analyzed. The trend defined by the ⁸⁷Sr/⁸⁶Sr signatures of both labile carbonate fractions and corresponding residual fractions indicates that a part of the labile carbonate fraction is genetically linked to the local soil composition. Considering the residual fraction of each sample as the most likely lithogenic source of Ca in carbonates, it is estimated that from 24% to 82% (55% on average) of Ca is derived from local bedrock weathering, leading to a consumption of an equivalent proportion of atmospheric CO₂. These values indicate that climatic conditions were humid enough to allow silicate weathering: MAR at the time of carbonate formation likely ranged from 400 to 700 mm, which is 2- to 3-fold less than the current MAR at these locations.The Sr, U and Mg contents and the (²³⁴U/²³⁸U) activity ratio in the labile carbonate fraction help to understand the conditions of carbonate formation. The relatively high concentrations of Sr, U and Mg in black soil carbonates may indicate fast growth and accumulation compared to carbonates in saprolite, possibly due to a better confinement of the pore waters which is supported by their high (²³⁴U/²³⁸U) signatures, and/or to higher content of dissolved carbonates in the pore waters. The occurrence of Ce, Mn and Fe oxides in the cracks of carbonate reflects the existence of relatively humid periods after carbonate formation. The carbonate ages determined by the U-Th method range from 1.33 ± 0.84 kyr to 7.5 ± 2.7 kyr and to a cluster of five ages around 20 kyr, i.e. the Last Glacial Maximum period. The young occurrences are only located in the black soils, which therefore constitute sensitive environments for trapping and retaining atmospheric CO₂ even on short time scales. The maximum age of carbonates depends on their location in the climatic gradient: from about 20 kyr for centimetric nodules at Mule Hole (MAR = 1100 mm/yr) to 200 kyr for the calcrete at Gundlupet (MAR = 700 mm/yr, Durand et al., 2007). The intensity of rainfall during wet periods would indeed control the lifetime of pedogenic carbonates and thus the duration of inorganic carbon storage in soils.  相似文献   

A catalog of tsunamis in New Caledonia from 28 March 1875 to 30 September 2009     

Alexandre Sahal  Bernard Pelletier  Jean Chatelier  Franck Lavigne  François Schindelé 《Comptes Rendus Geoscience》2010,342(6):434-447

In order to establish a tsunami alert system in New Caledonia in April 2008, the French Secretary of State for Overseas Affairs, with the aid of the UNESCO French Commission, mandated an investigation to build a more complete record of the most recent tsunamis. To complete this task, a call for witnesses was broadcast through various media and in public locations. These witnesses were then interviewed onsite about the phenomenon they had observed. Previous witness reports that had been obtained in the last few years were also used. For the most recent events, various archives were consulted. In total, 18 events were documented, of which 12 had not been previously mentioned in past work. These results confirm an exposure to a hazard of: (1) local origin (the southern part of the Vanuatu arc) with a very short post-seismic delay (< 30 min) before the arrival of wave trains; (2) regional origin (Solomon Islands arc, northern part of the Vanuatu arc) with a delay of several hours; and (3) an exposure to trans-oceanic tsunamis (Kamchatka 1952, South Chile 1960, Kuril Islands 2006, North Tonga 2009), unknown until today. These results highlight the necessity for New Caledonia to adopt an alert system, coupled with ocean tide gauges, that liaises with the main alert system for the Pacific (Pacific Tsunami Warning Center), and brings to light the importance of establishing a prevention campaign.  相似文献   

Pétrographie et géochimie comparées des pellets phosphatés et de leur gangue dans le gisement phosphaté de Ras-Draâ (Tunisie). Implications sur la genèse des pellets phosphatés     

Aida Ben Hassen  Jean Trichet  Jean-Robert Disnar  Habib Belayouni 《Swiss Journal of Geoscience》2010,103(3):457-473

Paléocène-Early Eocene phosphate outcrop in the Ras-Draâ deposit (Tunisia) comprises alternances of P-rich strata (P₂O₅ ≥ 18%) and P-poor ones (P₂O₅ ≤ 2%). In phosphate rich strata, P is concentrated in rounded grains—so-called pellets—(28% ≤ P₂O₅ ≤ 38%) embedded in a matrix—so-called exogangue—much poorer in P (P₂O₅ # 7%) than pellets. The study of pellets (whose size lies mainly between 100 and 500 μm), of their surrounding matrix and of poorly phosphatic sediments, interlayered between the phosphatic strata, has been performed by optical microscopy and various chemical analyses, ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectroscopy) and punctual chemical analyses by EDS (Energy Dispersive Spectroscopy). Mineralogical and chemical studies of the Tunisian phosphatic pellets show that the basic mineralogical component of these grains is carbonate-fluor-apatite, or francolite. The structural formula of a representative specimen of francolite in the basin is as follows: (Ca_4.63Mg_0.13Na_0.22)(PO₄)_2.51(CO₃)_0.48(OH_0.77F_0.23). The mineralogy of the constituents of the sediment surrounding pellets comprises carbonates, clays, silica (opal, quartz). Microscopic observations of Ras-Draâ phosphorites, added to geochemical results, establish that pellets are small bodies, allochtonous to their matrix and whose composition is independent of that of this matrix. Fecal cylindrical bodies and subspherical pellets, the latest being supposed to proceed from the fecal bodies by fragmentation, are considered to have been formed by fishes, as P-rich and organic matter-rich faeces. These faeces turn out to be resistant to mechanical dispersion and to chemical diffusion of soluble elements from and in direction of sea water. This closeness is responsible for the strong reducing conditions having prevailed inside and during the pellets diagenesis.  相似文献   

Bentho-planktonic evidence from the Austrian Alps for a decline in sea-surface carbonate production at the end of the Triassic     

Marie-Emilie Clémence  Silvia Gardin  Annachiara Bartolini  Guillaume Paris  Valérie Beaumont  Jean Guex 《Swiss Journal of Geoscience》2010,103(2):293-315

A high-resolution micropalaeontological study, combined with geochemical and sedimentological analyses was performed on the Tiefengraben, Schlossgraben and Eiberg sections (Austrian Alps) in order to characterize sea-surface carbonate production during the end-Triassic crisis. At the end-Rhaetian, the dominant calcareous nannofossil Prinsiosphaera triassica shows a decrease in abundance and size and this is correlated with a increase in δ¹⁸O and a gradual decline in δ¹³C_carb values. Simultaneously, benthic foraminiferal assemblages show a decrease in diversity and abundance of calcareous taxa and a dominance of infaunal agglutinated taxa. The smaller size of calcareous nannofossils disturbed the vertical export balance of the biological carbon pump towards the sea-bottom, resulting in changes in feeding strategies within the benthic foraminiferal assemblages from deposit feeders to detritus feeders and bacterial scavengers. These micropalaeontological data combined with geochemical proxies suggest that changes in seawater chemistry and/or cooling episodes might have occurred in the latest Triassic, leading to a marked decrease of carbonate production. This in turn culminated in the quasi-absence of calcareous nannofossils and benthic foraminifers in the latest Triassic. The aftermath (latest Triassic earliest Jurassic) was characterised by abundance peaks of “disaster” epifaunal agglutinated foraminifera Trochammina on the sea-floor. Central Atlantic Magmatic Province (CAMP) paroxysmal activity, superimposed on a major worldwide regressive phase, is assumed to be responsible for a deterioration in marine palaeoenvironments. CAMP sulfuric emissions might have been the trigger for cooling episodes and seawater acidification leading to disturbance of the surface carbonate production at the very end-Triassic.  相似文献   

The stress field at Soultz-sous-Forêts from focal mechanisms of induced seismic events: Cases of the wells GPK2 and GPK3     

Louis Dorbath  Keith Evans  Nicolas Cuenot  Benoît Valley  Jean Charléty  Michel Frogneux 《Comptes Rendus Geoscience》2010,342(7-8):600-606

The stress field at the EGS geothermal site of Soultz-sous-Forêts has been the subject of many studies, because it largely controls the response of the reservoir to fluid injection. The analysis of borehole logging data, especially breakouts and drilling-induced tension fractures, in the four geothermal wells define an average SHmax orientation ranging between 170° and 180° down to 5 km depth. It also reveals strong heterogeneities in several depth intervals. In this paper, the inversion of double-couple source mechanisms of seismic events induced during GPK2 and GPK3 stimulation tests is performed to retrieve the orientation and shape factor of the stress tensor, using the Slickenside Analysis Package of Michael, 1984, Michael, 1987a, Michael, 1987b. The results indicate a well-determined orientation of Shmin in GPK2 and in GPK3; in GPK3 Shmin is clockwise rotated by about 10°. The stress tensor defines an uniaxial extension. The results from both methods, analysis of borehole logging data and inversion of focal mechanisms, are only slightly different; the discrepancy may be due to the larger reservoir volume covered by the focal mechanisms, which can include strong stress heterogeneities.  相似文献   

A two‐step process for the reflooding of the Mediterranean after the Messinian Salinity Crisis     

François Bache  Speranta‐Maria Popescu  Marina Rabineau  Christian Gorini  Jean‐Pierre Suc  Georges Clauzon  Jean‐Louis Olivet  Jean‐Loup Rubino  Mihaela Carmen Melinte‐Dobrinescu  Ferran Estrada  Laurent Londeix  Rolando Armijo  Bertrand Meyer  Laurent Jolivet  Gwénaël Jouannic  Estelle Leroux  Daniel Aslanian  Antonio Tadeu Dos Reis  Ludovic Mocochain  Nikola Dumurdžanov  Ivan Zagorchev  Vesna Lesić  Dragana Tomić  M. Namık Çağatay  Jean‐Pierre Brun  Dimitrios Sokoutis  Istvan Csato  Gülsen Ucarkus  Ziyadin Çakır 《Basin Research》2012,24(2):125-153

The Messinian Salinity Crisis is well known to have resulted from a significant drop of the Mediterranean sea level. Considering both onshore and offshore observations, the subsequent reflooding is generally thought to have been very sudden. We present here offshore seismic evidence from the Gulf of Lions and re‐visited onshore data from Italy and Turkey that lead to a new concept of a two‐step reflooding of the Mediterranean Basin after the Messinian Salinity Crisis. The refilling was first moderate and relatively slow accompanied by transgressive ravinement, and later on very rapid, preserving the subaerial Messinian Erosional Surface. The amplitude of these two successive rises of sea level has been estimated at ≤500 m for the first rise and 600–900 m for the second rise. Evaporites from the central Mediterranean basins appear to have been deposited principally at the beginning of the first step of reflooding. After the second step, which preceeded the Zanclean Global Stratotype Section and Point, successive connections with the Paratethyan Dacic Basin, then the Adriatic foredeep, and finally the Euxinian Basin occurred, as a consequence of the continued global rise in sea level. A complex morphology with sills and sub‐basins led to diachronous events such as the so‐called ‘Lago Mare’.This study helps to distinguish events that were synchronous over the entire Mediterranean realm, such as the two‐step reflooding, from those that were more local and diachronous. In addition, the shoreline that marks the transition between these two steps of reflooding in the Provence Basin provides a remarkable palaeogeographical marker for subsidence studies.  相似文献   

Chronology of Vesuvius’ activity from A.D. 79 to 1631 based on archeomagnetism of lavas and historical sources     

Claudia?PrincipeEmail author  Jean?Claude?Tanguy  Simone?Arrighi  Anna?Paiotti  Maxime?Le?Goff  Ugo?Zoppi 《Bulletin of Volcanology》2004,66(8):703-724

The activity of Vesuvius between A.D. 79 and 1631 has been investigated by means of precise archaeomagnetic dating of primary volcanic deposits and taking into account the stratigraphy of lavas and tephra, historical written accounts, archaeological evidence related to the developing urbanisation, and radiocarbon ages. We found that the historical records are highly useful in constraining the timing of the main events, even if the data are often too scarce and imprecise for ascertaining the details of all phases of activity, especially their magnitude and emplacement of all the deposit types. In addition, some eruptions that took place in the 9^th and 10^th centuries appear to be unnoticed by historians. The archaeomagnetic study involved 26 sites of different lavas and 2 pyroclastic deposits. It shows that within the 15 centuries which elapsed between A.D. 79 and 1631, the effusive activity of Vesuvius clustered in the relatively short period of time between A.D. 787 and 1139 and was followed by a 5-century-long repose period. During this time Vesuvius prepared itself for the violent explosive eruption of 1631. The huge lavas shaping the morphology of the coast occurred largely through parasitic vents located outside the Mount Somma caldera. One of these parasitic vents is located at low elevation, very close to the densely inhabited town of Torre Annunziata. Among the various investigated lavas, a number of which were previously attributed to the 1631 eruption, none is actually younger than the 12^th century. Therefore it is definitively concluded that the destructive 1631 event was exclusively explosive.Editorial handling: J. McPhie  相似文献