Environmental risk evaluation of the use of mine spoils and treated sewage sludge in the ecological restoration of limestone quarries     

M. M. Jordán  S. Pina  F. García-Orenes  M. B. Almendro-Candel  E. García-Sánchez 《Environmental Geology》2008,55(2):453-462

The ecologic restoration criteria in areas degraded from extraction activities require making use of their mine spoils. These materials do not meet fertility conditions to guarantee restoration success and therefore, need the incorporation of organic amendments to obtain efficient substratum. Reducing the deficiencies in the organic material and restoration material nutrients with the contribution of treated sewage sludge is proposed in this work. This experiment was based on a controlled study using columns. The work was conducted with two mine spoils, both very rich in calcium carbonate. The first mineral, of poor quality, came from the formation of aggregates of crushed limestone (Z). The other residual material examined originated in limestone extraction, formed by the levels of interspersed non-limestone materials and the remains of stripped soils (D). Two treatments were undertaken (30,000 and 90,000 kg/ha of sewage sludge), in addition to a control treatment. The water contribution was carried out with a device that simulated either short-duration rain or a flooding irrigation system in order to cover the surface and then percolate through the soil. The collection of leached water took place 24 h after the applications. Different parameters of the leached water were determined, including pH, electrical conductivity, nitrate anions, ammonium, phosphates, sulphates and chlorides. The values obtained for each irrigation application are discussed, and the nitrate values obtained were very elevated.  相似文献   

Spatial data for landslide susceptibility, hazard, and vulnerability assessment: An overview   总被引：30，自引：0，他引：30  

Cees J. van Westen  Enrique Castellanos  Sekhar L. Kuriakose 《Engineering Geology》2008,102(3-4):112

The aim of this paper is to discuss a number of issues related to the use of spatial information for landslide susceptibility, hazard, and vulnerability assessment. The paper centers around the types of spatial data needed for each of these components, and the methods for obtaining them. A number of concepts are illustrated using an extensive spatial data set for the city of Tegucigalpa in Honduras. The paper intends to supplement the information given in the “Guidelines for Landslide Susceptibility, Hazard and Risk Zoning for Land Use Planning” by the Joint ISSMGE, ISRM and IAEG Technical Committee on Landslides and Engineered Slopes (JTC-1). The last few decades have shown a very fast development in the application of digital tools such as Geographic Information Systems, Digital Image Processing, Digital Photogrammetry and Global Positioning Systems. Landslide inventory databases are becoming available to more countries and several are now also available through the internet. A comprehensive landslide inventory is a must in order to be able to quantify both landslide hazard and risk. With respect to the environmental factors used in landslide hazard assessment, there is a tendency to utilize those data layers that are easily obtainable from Digital Elevation Models and satellite imagery, whereas less emphasis is on those data layers that require detailed field investigations. A review is given of the trends in collecting spatial information on environmental factors with a focus on Digital Elevation Models, geology and soils, geomorphology, land use and elements at risk.  相似文献   

A GPR study of subsidence-creep-fault processes in Morelia, Michoacán, Mexico     

Jorge A. Avila-Olivera  Víctor H. Garduo-Monroy 《Engineering Geology》2008,100(1-2):69-81

In 1983, inhabitants of the City of Morelia, Michoacán, Mexico, began to observe a series of differential settlements causing damages to constructions along linear trends parallel to a system of regional faults. The same phenomenon occurs in others cities of the Mexican Volcanic Belt (MVB), such as Celaya, Aguascalientes, and Querétaro, and is linked to a structurally controlled subsidence, caused by groundwater withdrawal, and the presence of geological faults. We define this subsidence type as Subsidence-Creep-Fault Processes (SCFP), based on the necessary elements for their generation, and we studied them through geophysical and geotechnical techniques. In Morelia, the geophysical investigations have been carried out using ground-penetrating radar (GPR). GPR profiles, perpendicular to the axis of the surface fault generated by the SCFP were carried out. The common-offset single-fold profiling was used, with a central frequency of 50 MHz. In all cases it has been possible to visualize a fault plane dividing two blocks, the presence of synthetic and antithetic faults, influence zones from 20 m to 40 m, and a maximum “net throw” of 4 m. Exploration trenches followed the same direction of the profiles obtained with GPR (perpendicular to the axis of the surface fault). These trenches exposed a fault plane dividing two blocks with different lithology, generating a maximum “net throw” of 4.40 m; as well they help in the determination of influence zones that varied from 14 m to 40 m.  相似文献   

Design of shallow foundations under tensile loading for transmission line towers: An overview     

M.P. Pacheco  F.A.B. Danziger  C. Pereira Pinto   《Engineering Geology》2008,101(3-4):226-235

Tensioned foundations are common in civil engineering applications such as transmission towers, harbors, offshore structures, basement slabs under pressure, industrial equipment, etc. Procedures for the design of tensioned foundations are discussed in this paper, including specific recommendations for more common transmission tower foundations. Starting from a distinction between shallow and deep modes of failure, the paper presents the most common failure mechanisms for shallow failure in tension, including procedures for calculation of foundation tensile capacity under vertical and inclined loading. Emphasis is given to the influence of the strength of the compacted backfill compared to the strength of the natural soil, including presentation of results of full-scale loading tests.  相似文献   

Discussion on “Experimental study on fracture toughness and tensile strength of a clay” [Engineering Geology 94 (2007) 64–75]     

M.R. Lakshmikantha  P.C. Prat  A. Ledesma 《Engineering Geology》2008,101(3-4):295-296

The paper [Wang, J.-J., Zhu, J.-G., Chiu, C.F., Zhang, H., 2007. Experimental study on fracture toughness and tensile strength of a clay. Engineering Geology 94, 64–75.] focuses on two important fracture parameters of soils: tensile strength and fracture toughness. These parameters control the behaviour of soils in a wide range of situations, from the design of a simple footing to much complicated fracture behaviour of clay liners or covers. The authors have done extensive laboratory work to determine these two parameters and their laborious and complicated experimental program needs praise. However, some of the points raised in their conclusions, based on the analysis and comparison with the data from the literature, need to be discussed.  相似文献   

Age of the Earth’s crust and the Nd isotopic composition of the mantle sources of East Antarctic complexes     

E. V. Mikhalsky 《Geochemistry International》2008,46(2):168-174

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Composition, P-T parameters, and metasomatic transformations of mafic schists of the Svyatoi Nos Peninsula, Eastern Baikal Area     

V. A. Makrygina  Z. I. Petrova  A. A. Koneva  L. F. Suvorova 《Geochemistry International》2008,46(2):140-155

The paper reports data on rock and mineral compositions from the Svyatonosskaya Formation, which is a continuation of the Ol’khon Series in the northern part of the Svyatoi Nos Peninsula, eastern shore of Lake Baikal. The pyroxene-amphibole-plagioclase schists (metagabbro) are replaced there by the garnet-biotite-quartz assemblage, which was formed, according to the data of various geothermometers and calculations by the THERMOCALC computer program, under conditions corresponding to the transition from the granulite (848–811°C) to high grades of the amphibolite (715–670°C) facies under high pressures (8.7 ±1.6 kbar). In petrogenetic grids, these conditions fall onto the line of the onset of eclogitization. In nature these rocks are a continuation of the Chernorudskaya-Barakchinskaya zone of elevated pressures in the Ol’khon area. The metasomatic rocks were formed simultaneously with strike-slip faulting, when coupled zones of relatively high-(eclogite-like) and low-pressure (quartzite-marble melange) developed at the inflow of SiO₂ and K₂O and the removal of MgO and CaO. Analogous compositional changes in gneisses and schists in tectonic extension zones in Ol’khon Island and neighboring areas occurred during the development of migmatites. The migmatization of the gneisses was likely coupled with the garnetization of mafic schists in high-pressure zones and the formation of eclogite-like rocks replacing marbles. The accompanying graphitization of this block suggests that the metasomatic fluid had a hydrocarbon-hydrogen composition.  相似文献   

Diamond formation in sulfide pyrrhotite-carbon melts: Experiments at 6.0–7.1 GPa and application to natural conditions     

A. V. Shushkanova  Yu. A. Litvin 《Geochemistry International》2008,46(1):37-47

Experiments at 6.0–7.1 GPa and 1500–1700°C were carried out to explore the boundary conditions of diamond nucleation and growth in pyrrhotite-carbon melt-solutions. Pyrrhotite is one of the main sulfide minerals of the pyrrhotite-pentlandite-chalcopyrite assemblage of mantle rocks and primary inclusions in diamond. Solutions of carbon in sulfide melts oversaturated with respect to diamond at the expense of the dissolution of starting graphite (thermodynamically unstable phase) are formed owing to the difference between the solubilities of graphite and diamond, which increases under the influence of temperature gradients in experimental samples. We determined the fields of carbon solutions in pyrrhotite melt showing labile and metastable oversaturation with respect to diamond, which correspond to the spontaneous nucleation of the diamond phase and diamond growth on seeds, respectively. The linear growth rate of diamond in sulfide-carbon melts is rather high (on average, 10 μ/min during the first 1–2 min from the onset of spontaneous crystallization). The nucleation density is estimated as 180 grains per cubic centimeter. Diamonds crystallized from sulfide melts show octahedral and spinel twin shapes. Diamond polycrystals were synthesized for the first time from a sulfide medium as intergrowths of skeletal (edge) or “cryptocrystalline” microdiamonds, from 1 to 100 μm in size, their spinel twins and, occasionally, polysynthetic (star-shaped) twins. During diamond growth from sulfidecarbon melts on smooth faces of cuboctahedral diamond seeds synthesized in metal systems, smooth-faced layer-by-layer step-like growth was observed on their octahedral (111) faces, whereas growth on the (100) cubic faces produced rough-surfaced layers of intergrown micropyramids, whose axes were oriented normal to the (100) face. The obtained experimental results were applied to the problem of diamond genesis under the conditions of the Earth’s mantle in the framework of the model of carbonate-silicate parental melts with blebs of immiscible sulfide melts.  相似文献   

Geochemistry of late stage medium to high-K calc-alkaline and shoshonitic dykes in the Ulukişla Basin (Central Anatolia, Turkey): Petrogenesis and tectonic setting     

M. A. Kurt  M. Alpaslan  M. C. Göncüoǧlu  A. Temel 《Geochemistry International》2008,46(11):1145-1163

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Chemical composition of atmospheric precipitates within the influence zone of the Severonikel Smelter   总被引：1，自引：1，他引：0  

V. A. Dauval’ter  M. V. Dauval’ter  N. V. Saltan  E. N. Semenov 《Geochemistry International》2008,46(10):1064-1069

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