Based on data on the composition of ore-bearing hydrothermal solutions and parameters of ore-forming processes at various antimony and antimony-bearing deposits, which were obtained in studies of fluid inclusions in ore minerals, we investigated the behavior of Sb(III) in the system Sb–Cl–H2S–H2O describing the formation of these deposits.
We also performed thermodynamic modeling of native-antimony and stibnite dissolution in sulfide (mHS− = 0.0001−0.1) and chloride (mCl− = 0.1−5) solutions and the joint dissolution of Sb(s)0 and Sb2S3(s) in sulfide-chloride solution (mHS− = 0.01; mCl− = 1) depending on Eh, pH, and temperature. All thermodynamic calculations were carried out using the Chiller computer program. Under the above conditions, stibnite precipitates in acid, weakly acid to neutral, and medium redox solutions, whereas native antimony precipitates before stibnite under more reducing conditions in neutral to alkaline solutions.
The metal-bearing capacity of hydrothermal solutions (200–250 °C) of different compositions and origins has been predicted. We have established that the highest capacity is specific for acid (pH = 2–3) high-chloride solutions poor in sulfide sulfur and alkaline (pH = 7–8) low-chloride low-sulfide solutions. 相似文献
The distributions of the partial pressure of carbon dioxide (pCO2) and total alkalinity (TA) were examined for a 6-month period in the Wailuku and Wailoa rivers and coastal waters of Hilo
Bay on the west coast of the Island of Hawaii, USA. Main results for the largest and turbulent Wailuku River show in the watershed
an oversaturation in CO2 with respect to atmospheric equilibrium and a CO2 undersaturation in the estuary. In the Wailoa river-estuary system, extremely high pCO2 values ranging from 1500 to 10500 ppm were measured with significant shifts in pCO2 from drought to flood period. In the two rivers, water residence time, groundwater inputs and occasional flood events are
the predominant drivers of the spatial and temporal patterns in the distribution of pCO2. In Hilo Bay, CO2 oversaturation dominates and the bay was a source of CO2 to the atmosphere during the study period. TA is conservative along the salinity gradient, indicating calcification in the
bay is not a significant source of CO2 to the atmosphere. 相似文献
Mountain regions are subject to a variety of hazardous processes. Earthquakes, landslides, snow avalanches, floods, debris
flows, epidemics and fires, among other processes, have caused injury, death, damage and destruction. They also face challenges
from increased populations, and expansion and intensification of␣activities, land uses and infrastructure. The combination
of a dynamic bio- geophysical environment and intensified human use has increased the vulnerability of mountain social–ecological
systems to risk from hazards. The ability of social–ecological systems to build resilience in the context of hazards is an
important factor in their long-term sustainability. The role of resilience building in understanding the impact of hazards
in mountain areas is examined and illustrated, in part, through examples from Canada and India. Resilient social–ecological
systems have the ability to learn and adjust, use all forms of knowledge, to self-organize and to develop positive institutional
linkages with other social–ecological systems in the face of hazards. The analysis suggests that traditional social–ecological
systems built resilience through avoidance, which was effective for localized hazards. The more recent development and implementation
of cross-scale institutional linkages is shown to be a particularly effective means of resilience building in mountain social–ecological
systems in the face of all hazards. 相似文献
Ardesen is a settlement area which has been significantly damaged by frequent landslides which are caused by severe rainfalls
and result in many casualties. In this study a landslide susceptibility map of Ardesen was prepared using the Analytical Hierarchy
Process (AHP) with the help of Geographical Information Systems (GIS) and Digital Photogrametry Techniques (DPT). A landslide
inventory, lithology–weathering, slope, aspect, land cover, shear strength, distance to the river, stream density and distance
to the road thematics data layers were used to create the map. These layer maps are produced using field, laboratory and office
studies, and by the use of GIS and DPT. The landslide inventory map is also required to determine the relationship between
these maps and landslides using DPT. In the study field in the Hemsindere Formation there are units that have different weathering
classes, and this significantly affects the shear strength of the soil. In this study, shear strength values are calculated
in great detail with field and laboratory studies and an additional layer is evaluated with the help of the stability studies
used to produce the landslide susceptibility map. Finally, an overlay analysis is carried out by evaluating the layers obtained
according to their weight, and the landslide susceptibility map is produced. The study area was classified into five classes
of relative landslide susceptibility, namely, very low, low, moderate, high, and very high. Based on this analysis, the area
and percentage distribution of landslide susceptibility degrees were calculated and it was found that 28% of the region is
under the threat of landslides. Furthermore, the landslide susceptibility map and the landslide inventory map were compared
to determine whether the models produced are compatible with the real situation resulting in compatibility rate of 84%. The
total numbers of dwellings in the study area were determined one by one using aerial photos and it was found that 30% of the
houses, with a total occupancy of approximately 2,300 people, have a high or very high risk of being affected by landslides. 相似文献
The 1:500,000 geological, tectonic and hydrogeological maps of Switzerland have been updated using a new approach for a geographical
information system (GIS). Geological, tectonic and hydrogeological data are combined in a single polygon data set. Specific
data (point and line elements) are additionally represented on a separate GIS layer for each map respectively. The new 1:500,000
hydrogeological map of Switzerland consists of two different sheets. The first sheet provides information on the near-surface
groundwater resources and qualitative estimates of their yield. The second sheet displays the groundwater resource vulnerability
and the capacity of lateral contaminant transport. The 1:100,000 hydrogeological map of Switzerland shows the distribution
and use of groundwater in a selected area. The near-surface consolidated and unconsolidated rocks are classified in this map
according to their permeability and lithological and petrographical properties. The map is available as a pixel map.
Résumé Les cartes aux 1:500,000 de la Suisse, portant sur la géologie, la tectonique et l’hydrogéologie, ont été mises à jour en
utilisant une nouvelle approche pour un système d’information géographique (GIS, en anglais). Les données géologiques, tectoniques
et hydrogéologiques ont été combinées sur un seul set de polygones. Les données plus spécifiques (points et lignes) sont représentées
dans une couverture séparée, pour chaque carte respectivement. La nouvelle carte hydrogéologique de Suisse au 1:500,000 est
constituée de deux différentes feuilles. La première feuille apporte des informations sur les ressources proches de la surface
et sur leur rendement. La seconde feuille montre la vulnérabilité des ressources souterraines et le risque de pollution par
transport latéral. La carte hydrogéologique de Suisse au 1:100,000 montre la distribution et l’utilisation de l’eau souterraine
dans la région sélectionnée. Les roches consolidées ou meubles de sub-surface, sont classées au regard de leur perméabilité
et de leurs propriétés lithologique et pétrographique. La carte est disponible pixellisée.
Resumen Los mapas geológico, tectónico e hidrogeológico de Suiza a escala 1:500,000 han sido actualizados utilizando un nuevo enfoque
para un sistema de información geográfico (SIG). Los datos geológicos, tectónicos e hidrogeológicos se combinan en un conjunto
de datos en un solo polígono. Por otra parte, para cada uno de los mapas, los datos específicos (elementos puntuales y lineales)
se representaron en una capa separa del SIG. El nuevo mapa hidrogeológico de Suiza a escala 1:500,000 contiene dos capas diferentes.
La primera de ellas suministra información de los recursos hídricos subterráneos poco profundos y estimaciones cualitativas
de sus rendimientos. La segunda capa muestra la vulnerabilidad de este recurso y el riesgo debido al transporte lateral de
contaminantes. El mapa hidrogeológico de Suiza a escala 1:100,000 muestra la distribución y uso del agua subterránea en un
área seleccionada. Los sedimentos consolidados y no consolidados cercanos a la superficie se clasifican en este mapa en función
de su permeabilidad y propiedades litológicas y petrográficas. El mapa se encuentra disponible como un mapa de pixeles.