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1.
This paper presents an example of application of the double solid reactant method (DSRM) of Accornero and Marini (Environmental
Geology, 2007a), an effective way for modeling the fate of several dissolved trace elements during water–rock interaction. The EQ3/6 software
package was used for simulating the irreversible water–rock mass transfer accompanying the generation of the groundwaters
of the Porto Plain shallow aquifer, starting from a degassed diluted crateric steam condensate. Reaction path modeling was
performed in reaction progress mode and under closed-system conditions. The simulations assumed: (1) bulk dissolution (i.e.,
without any constraint on the kinetics of dissolution/precipitation reactions) of a single solid phase, a leucite-latitic
glass, and (2) precipitation of amorphous silica, barite, alunite, jarosite, anhydrite, kaolinite, a solid mixture of smectites,
fluorite, a solid mixture of hydroxides, illite-K, a solid mixture of saponites, a solid mixture of trigonal carbonates and
a solid mixture of orthorhombic carbonates. Analytical concentrations of major chemical elements and several trace elements
(Cr, Mn, Fe, Ni, Cu, Zn, As, Sr and Ba) in groundwaters were satisfactorily reproduced. In addition to these simulations,
similar runs for a rhyolite, a latite and a trachyte permitted to calculate major oxide contents for the authigenic paragenesis
which are comparable, to a first approximation, with the corresponding data measured for local altered rocks belonging to
the silicic, advanced argillic and intermediate argillic alteration facies. The important role played by both the solid mixture
of trigonal carbonates as sequestrator of Mn, Zn, Cu and Ni and the solid mixture of orthorhombic carbonates as scavenger
of Sr and Ba is emphasized.
相似文献
| Luigi Marini (Corresponding author)Email: |
2.
Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts on aquatic ecosystems are aluminum, copper, zinc, and arsenic because these elements locally exceed toxicity guidelines for surface waters or for stream sediments. Acid-mine drainage has not developed in streams draining inactive copper mines. Acid-rock drainage and chemical weathering processes that accompany debris flows or human disturbances of sulfidic rocks are comparable to processes that develop acid-mine drainage elsewhere. Despite the high rainfall in the mountain range, sheltered areas and intermittent dry spells provide local venues for development of secondary weathering products that can impact aquatic ecosystems.Electronic Supplementary Material Supplementary material is available for this article if you access the article at . A link in the frame on the left on that page takes you directly to the supplementary material.
相似文献
| Jane M. HammarstromEmail: Phone: +1-703-6486165Fax: +1-703-6486252 |
3.
Dorian Speakman 《Natural Hazards》2008,44(1):111-127
A vulnerability index for the Fire Service in the UK has been designed to identify vulnerable locations during episodes of
severe floods. Taking recent case studies with the UK Fire Service, the patterns of vulnerability, in terms of demand on time
and resources, can be explained by investigating the environmental causes and their interaction with the adaptive capacity
of the response agencies.
相似文献
| Dorian SpeakmanEmail: |
4.
Modeling stream-aquifer interactions in a shallow aquifer, Choele Choel Island, Patagonia, Argentina 总被引：3，自引：1，他引：2
A groundwater/surface-water interaction model was developed for the shallow alluvial aquifer of the Choele Choel Island in
Patagonia, Argentina. In this semiarid climate, agriculture is sustained by an irrigation/drainage system. During the irrigation
season, seepage losses through unlined distribution canals in irrigated fields contribute to elevated groundwater levels,
jeopardizing fruit productivity in some areas. Moreover, high stream stages during the irrigation season interfere with groundwater
drainage. The model utilized MODFLOW and its stream package, and was successfully calibrated for a historical irrigation season.
Modeling results indicate that drainage through streams is significantly higher than drainage through artificial drains. The
stream/aquifer relationship proved very responsive to water table rises caused by irrigation. This response manifested as
changes in the gaining/losing character of stream reaches. A synthetic run aimed at isolating the effect of streamflow changes
on groundwater levels showed that the effect of higher streamflows dissipates toward the interior of the island, disappearing
completely at the island center. Even though some results were qualitative, the model helped to provide a better understanding
of the coupled system to elucidate some of the causes of a rising water table on the island.
相似文献
| Leticia B. RodríguezEmail: |
5.
P. Mogilevsky 《Physics and Chemistry of Minerals》2007,34(3):201-214
The regular solid solution model has been applied to solid solubility in the monazite–xenotime systems and is verified against
the available experimental data for LaPO4–YPO4 and CePO4–YPO4 systems. The model is then used to predict the miscibility gaps in a number of other monazite–xenotime systems. The implications
for prospective two-phase monazite–xenotime fiber coatings for applications in ceramic matrix composites (CMCs) are discussed.
相似文献
| P. MogilevskyEmail: |
6.
Anthony John Christopher 《GeoJournal》2006,67(2):123-136
The pattern of Church of England dioceses has evolved over a period of 1,400 years. It reflects the practical response of
the Church to the changing political and demographic patterns of the country. No ideal size and form of diocese was ever devised
and few systematic attempts were made to achieve a degree of equity between them. The constitutional link between state and
church has inhibited change for the last 80 years, although society has changed significantly. Nevertheless, rapid constitutional
reforms, especially in the House of Lords, may be reflected in ecclesiastical reorganisation of the dioceses.
相似文献
| Anthony John ChristopherEmail: |
7.
Predicting environmental conditions to minimise salt damage at the Tower of London: a comparison of two approaches 总被引：1，自引：0，他引：1
Clifford A. Price 《Environmental Geology》2007,52(2):369-374
The paper compares the results of two studies of salt damage at the Wakefield Tower, Tower of London. The first, in 1993,
was based on semi-quantitative salt analysis and hygroscopicity measurements. The second was based on quantitative analysis
and a thermodynamic model, ECOS. Both studies aimed to predict environmental conditions that would minimise salt damage to
the interior stonework. Their predictions are markedly different, and this paper examines the reasons for the differences.
It is shown that hygroscopicity alone is not a reliable indicator of crystallisation from mixed salt solutions.
相似文献
| Clifford A. PriceEmail: |
8.
Melt inclusion formation mechanisms and compositional effects in high-An feldspar and high-Fo olivine in anhydrous mafic silicate liquids 总被引：1，自引：1，他引：0
Important aspects of melt inclusion formation and potential compositions effects have been addressed through a series of experiments using anorthite/fosterite saturated anhydrous mafic liquids. Experimental charges were cooled from 1,300 to 1,230 and 1,210°C at rates of 1–10°/min followed by 0–24 h isothermal periods. Hopper and skeletal crystal morphologies with variable degrees of completeness developed during the cooling period. Planar overgrowth of these textures during isothermal periods led to the formation of inclusions, the majority of which formed after 6 h of isothermal run time. We suggest that the change in morphologies is related to a decrease in growth rates and changes in dominant growth mechanisms. In general, inclusion compositions were uniform and similar to the host glass, indicating that with the isothermal times required for most inclusions to form, a boundary layer was not entrapped that could be detected within the limits of our analyses.
相似文献
| Edward KohutEmail: Phone: +1-541-7373023Fax: +1-541-7371200 |
| Roger L. NielsenEmail: Phone: +1-541-7371235 |
9.
This paper describes an application of the geographic information system (GIS) technology to a ground stability assessment
in the karst area of Dzerzhinsk, Russia. In the stability analysis, the groundwater level changes in the karst aquifer could
cause suffosion sinkholes when the gravitational force was greater than the soil strength. The GIS technology was used to
combine various data and to delineate the zones of potential gravitational collapse and suffosion collapse in the area.
相似文献
| V. V. TolmachevEmail: |
10.
Spatial and temporal knowledge representation 总被引：1，自引：1，他引：0
Antony Galton 《Earth Science Informatics》2009,2(3):169-187
Knowledge Representation (KR) originated as a discipline within Artificial Intelligence, and is concerned with the representation
of knowledge in symbolic form so that it can be stored and manipulated on a computer. This article surveys that part of KR
that is concerned with the representation of space and time, with particular reference to the use of such representations
in geographical information science.
相似文献
| Antony GaltonEmail: |
11.
The aim of this paper is to use an economic framework to derive decision making rules for river basin management with a focus on groundwater resources. Using an example from northern Nigeria, the paper provides an example of how decision making for sustainable water resources management may be facilitated by comparing net benefits and costs across a river basin. It is argued that economic tools can be used to assess the value of water resources in different uses, identify and analyze management scenarios, and provide decision rules for the sustainable use and management of surface and ground water resources in the region.
相似文献
| Gayatri AcharyaEmail: |
12.
Said Ettazarini 《Environmental Geology》2006,50(6):919-929
This study takes the groundwater of the Moroccan limestone aquifer of Oum Er-Rabia as an example of statistical and cartographical approaches in water resources management. Statistical analyses based on frequency distribution and PCA methods revealed the homogeneity of waters with the existence of abnormal points and have helped to assess correlations between the studied variables. The mapping approach illustrated that waters are influenced by the lithology of the surrounding rocks and are of Ca–Mg–HCO3, Ca–Mg–Cl–SO4, and mixed types according to the Piper classification. The quality of water is of high to medium, north of the basin, but it is of medium to bad, NE and south, due to excessive contents of chloride, sulfate and nitrate. According to the US Salinity Laboratory classification, water used for irrigation in the eastern and the southern parts of the basin should take into consideration the drainage conditions, the nature of plants and the addition of gypsum doses.
相似文献
| Said EttazariniEmail: Phone: +212-66-407610 |
13.
Space Physics Interactive Data Resource—SPIDR 总被引：1，自引：0，他引：1
Mikhail Zhizhin Eric Kihn Rob Redmon Dmitry Medvedev Dmitry Mishin 《Earth Science Informatics》2008,1(2):79-91
SPIDR (Space Physics Interactive Data Resource) is a standard data source for solar-terrestrial physics, functioning within
the framework of the ICSU World Data Centers. It is a distributed database and application server network, built to select,
visualize and model historical space weather data distributed across the Internet. SPIDR can work as a fully-functional web-application
(portal) or as a grid of web-services, providing functions for other applications to access its data holdings.
相似文献
| Mikhail ZhizhinEmail: |
14.
Summary The question of alternative technologies for high-speed Internet access lies at the heart of rural development problems. In
this paper, we focus on one of those technologies, the system combining satellite technologies and Wi-Fi. Based on an empirical
study carried out in three rural areas, we analyze the dynamics of the use and appropriation of that technology by the companies
and organizations participating in the experiment. Considered both from a technical and social standpoint, the technology
‘in use’ appears here in its structuring dimensions.
相似文献
| Valérie FautreroEmail: |
15.
Craig W. Morgan Graham M. Kent Gordon G. Seitz Michaela Novak 《Hydrogeology Journal》2008,16(5):981-994
A hydrogeologic model that has been used by many researchers and consultants to describe an area of South Lake Tahoe, California,
USA impacted by MTBE contamination describes a relatively homogeneous unconfined aquifer comprised of poorly sorted glacial
outwash deposits, within which water-supply wells are able to exert significant alteration in natural groundwater flow. A
re-examination of the area’s hydrogeology is presented, which supports a layered heterogeneous aquifer system constructed
of alternating fine and coarser-grained glacio-lacustrine depositional units. This re-evaluation was accomplished through
a review of lithologic logs across an area of approximately 1 km2, combined with observations of significant hydraulic head differences and knowledge of the depositional environments controlled
by Pleistocene Lake Tahoe high stands. Many of the fine-grained units observed at depths from 6 to 15 m, although relatively
thin, are generally continuous and serve as significant barriers to groundwater flow. The vertical migration of contamination
across these fine-grained units to deeper groundwaters was facilitated by cross-screened monitoring wells installed as part
of site investigation activities. This conclusion highlights the importance of geologic characterization and proper monitoring
well construction at contaminated site investigations.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
| Michaela NovakEmail: |
16.
Sarah F. Ives 《GeoJournal》2009,74(3):245-255
Using a discussion of South African soap operas, I will place the idea of visuality in a discourse analysis that incorporates
a feminist epistemological lens, or an epistemology that integrates reflexivity and an acknowledgment of the dialogic nature
of visual media. Through this discussion, I will examine the possibilities that dialogism provides for unpacking and exploring
the politics of imperfect translation between the visual and the textual. These methodological interventions, I argue, will
help enrich discussions of the visual’s role in the contested realm of geographic imaginations and move beyond the distanced
position of the masculine gaze.
相似文献
| Sarah F. IvesEmail: |
17.
A Double Solid Reactant Method was elaborated from a suggestion of Marini (Geological sequestration of carbon dioxide: Thermodynamics,
kinetics, and reaction path modeling. Developments in Geochemistry, Elsevier, Amsterdam, 2007) to simulate the release of
trace elements during the progressive dissolution of solid phases. The method is based on the definition, for each dissolving
solid, of both an entity whose thermodynamic and kinetic properties are known (either a pure mineral or a solid mixture) and
a special reactant, that is, a material of known stoichiometry and unknown thermodynamic and kinetic properties. The special
reactant is utilised to take into account the concentrations of trace elements in the dissolving solid phase. In this communication,
the influence of several trace elements on the ΔG
f
o, ΔG
r
o and log K of the minerals considered by Lelli et al. (Environ Geol, 2007) and Accornero and Marini (Geobasi, 2007a; Proceedings of
IMWA symposium, Cagliari, 27–31 May 2007b) was evaluated assuming ideal mixing in the solid state. These effects were found
to be negligible for albite and the leucite–latitic glass, limited for muscovites and chlorites, and slightly more important
for apatites. These influences become progressively higher with increasing concentration of trace elements in these minerals.
Based on these deviations in thermodynamic parameters, special reactants should not include oxide components with molar fractions
higher than 0.003.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
| Luigi MariniEmail: |
18.
Igor Vojnovic 《GeoJournal》2007,69(4):271-300
Throughout the 20th century, government in the U.S. has gone through significant changes; initially responding to the disorder
of early capitalism, and later, to the economic crisis of the 1970s. This article will explore the changes in the U.S. political
landscape over the last century, as well as the recent rise of neo-liberalism. In addition, with the analysis of the model
laissez-faire municipal government, the City of Houston, the article will illustrate how the basic weaknesses of neoliberalism
at the national level are also evident at the local scale of government.
相似文献
| Igor VojnovicEmail: |
19.
Michele Spizzico 《Hydrogeology Journal》2005,13(3):493-505
High concentrations of 222Rn have been found throughout the waters of the coastal carbonate-rock Mesozoic aquifer located in the region of Apulia in southern Italy. Studies undertaken have determined that such concentrations are due to the radioisotopic features of terra rossa, a type of paleosol that is generated as a residual byproduct of carbonate dissolution and is found to be widespread throughout the aquifers fissures and karst cavities.These special types of soil feature a rather high clay content (80–95%) and, although variable, their specific 226Ra activity (70–147 Bq/kg) is nonetheless considerably greater than that of limestone (~50 Bq/kg). In fact, there are substantial differences in 222Rn concentrations found in waters that come into contact with this type of rock and paleosol.The partial dissolution of some carbonate rock samples in the laboratory confirmed that the 226Ra released by the dissolved rock primarily accumulates in the residual soil deposits, especially in ones containing finer granules. This has also been the result of experiments conducted on 15 terra rossa samples collected from the region, which indicates that there is a close correlation between the specific 226Ra activity and the clay content of such paleosols, which varies with the stage of weathering.It has been found that the 222Rn concentrations in the regions waters, depend on the specific terra rossa 226Ra activity rather than on the quantity of terra rossa.Field checks have confirmed the possibility of using 226Ra and 222Rn as natural tracers in order to define hydrogeological problems in special environments such as karst. They can be used to distinguish the different water bearing zones in the carbonate-rock aquifer; analyze the influence of tides on coastal springs; determine the flow direction in the proximity of a well; recognize, recharge and the progressive decline of the groundwater level; derive indications of underground flow paths; and the occurrence of fissures and karstic cavities in the carbonate-rock aquifer.
相似文献
| Michele SpizzicoEmail: Phone: +39-080-5963676Fax: +39-080-5963675 |
20.
David Havlick 《GeoJournal》2007,69(3):151-164
Since 1988, more than 20 US military bases have been redesignated as national wildlife refuges. In order to understand the
processes of these military-to-wildlife (M2W) conversions and their implications, I examine three logics that help to produce
these particular changes: Biodiversity, Brownfields, and Serendipity. These logics contribute to a broader discourse of ecological
militarization that frames military practices as compatible with and contributing to environmental protection. I focus on
the case of the Rocky Mountain Arsenal, Colorado, USA, to examine how these logics of conversion are mobilized into practice,
and what such changes mean as they bring militarism and environmental conservation together in reconfigured spaces.
相似文献
| David HavlickEmail: |