Groundwater recharge in semi-arid carbonate aquifers under intensive use: the Estepa Range aquifers (Seville, southern Spain)   总被引：2，自引：1，他引：1  

Sergio Martos-Rosillo  Miguel Rodríguez-Rodríguez  Antonio Pedrera  J. Javier Cruz-SanJulián  J. Carlos Rubio 《Environmental Earth Sciences》2013,70(6):2453-2468

Quantifying groundwater recharge in carbonate aquifers located in semi-arid regions and subjected to intensive groundwater use is no easy task. One reason is that there are very few available methods suitable for application under such climatic conditions, and moreover, some of the methods that might be applied were originally designed with reference to non-carbonate aquifers. In addition, it is necessary to take into account the fact that, in any given aquifer, groundwater recharge is modified by the groundwater exploitation. Here we focus on four methods selected to assess their suitability for estimating groundwater recharge in carbonate aquifers affected by intensive exploitation. The methods were applied to the Estepa Range aquifers of Seville, southern Spain, which are subjected to different degrees of exploitation. Two conventional methods were used: chloride mass balance and daily soil–water balance. These results were compared with the results obtained by means of two non-conventional methods, designed for application to the carbonate aquifers of southern Spain: the APLIS and ERAS methods. The results of the different methods are analogous, comparable to those obtained in nearby non-exploited carbonate aquifers, confirming their suitability for use with carbonate aquifers in either natural or exploited regimes in a semi-arid climate.  相似文献   

Cosmic impact versus terrestrial origin of the Azuara structure (Spain): A review     

Angel L. Corts  Enrique Díaz‐Martínez  Enrique Sanz‐Rubio  Jesús Martínez‐Frías  Cristina Fernndez 《Meteoritics & planetary science》2002,37(6):875-894

Abstract— The Azuara structure is the largest one proposed so far in Spain as possibly related to a cosmic impact event. A review of the evidence set forward in favor of and against its cosmic origin indicates that the discussion is not yet finished. Some megascopic features (inverted stratigraphy, megabreccia, negative gravity anomalies) and shock‐metamorphic effects (planar deformational features) have been described in relation with the structure, although their real significance has been questioned and is still being debated. Comparison with other similar‐sized verified impacts suggests that unequivocal impactogenic features are yet to be found before the Azuara structure can be related to a cosmic impact. Until then, the Azuara structure should be considered as an unverified impact structure, and should not be included in global comprehensive maps of terrestrial impact structures.  相似文献   

Granular-Scale Elementary Flux Emergence Episodes in a Solar Active Region     

S. Vargas Domínguez  L. van Driel-Gesztelyi  L. R. Bellot Rubio 《Solar physics》2012,278(1):99-120

We analyse data from Hinode spacecraft taken over two 54-minute periods during the emergence of AR 11024. We focus on small-scale portions within the observed solar active region and discover the appearance of very distinctive small-scale and short-lived dark features in Ca ii H chromospheric filtergrams and Stokes I images. The features appear in regions with close-to-zero longitudinal magnetic field, and are observed to increase in length before they eventually disappear. Energy release in the low chromospheric line is detected while the dark features are fading. Three complete series of these events are detected with remarkably similar properties, i.e. lifetime of ≈ 12 min, maximum length and area of 2 – 4 Mm and 1.6 – 4 Mm², respectively, and all with associated brightenings. In time series of magnetograms a diverging bipolar configuration is observed accompanying the appearance of the dark features and the brightenings. The observed phenomena are explained as evidencing elementary flux emergence in the solar atmosphere, i.e. small-scale arch filament systems rising up from the photosphere to the lower chromosphere with a length scale of a few solar granules. Brightenings are explained as being the signatures of chromospheric heating triggered by reconnection of the rising loops (once they have reached chromospheric heights) with pre-existing magnetic fields, as well as being due to reconnection/cancellation events in U-loop segments of emerging serpentine fields. The characteristic length scale, area and lifetime of these elementary flux emergence events agree well with those of the serpentine field observed in emerging active regions. We study the temporal evolution and dynamics of the events and compare them with the emergence of magnetic loops detected in quiet Sun regions and serpentine flux emergence signatures in active regions. The physical processes of the emergence of granular-scale magnetic loops seem to be the same in the quiet Sun and active regions. The difference is the reduced chromospheric emission in the quiet Sun attributed to the fact that loops are emerging in a region of lower ambient magnetic field density, making interactions and reconnection less likely to occur. Incorporating the novel features of granular-scale flux emergence presented in this study, we advance the scenario for serpentine flux emergence.  相似文献   

Isopropylxanthate ions uptake by modified natural zeolite and removal by dissolved air flotation     

C.R. Oliveira  J. Rubio   《International Journal of Mineral Processing》2009,90(1-4):21-26

This work describes a laboratory study concerning the adsorption of isopropylxanthate ions onto modified zeolites particles. The separation of the loaded carrier and their removal, from aqueous solutions, was conducted by flocculation followed by dissolved air flotation, DAF. The zeolite employed was a natural sample (approximately 48% clinoptilolite and 30% mordenite) which was previously treated with sodium ions (activation) and modified with copper ions (Cu–Z) before the xanthate ions uptake. Adsorption capacities (q_m) for Cu–Z were 0.34 meq g^− 1 for the powdered form, and 1.12 meq g^− 1 for the floc form. The adsorption capacity for the floc form appears to involve an enhanced electrostatic adsorption due to the positive sites on the floc surface. In all cases, the isopropylxanthate concentration in the treated water was found to be negligible (< 0.04 mg L^{− 1}). The flotation technique showed to be a fast process, requires a low recycle ratio (20%) in air saturated water, and the treated water ended up with a very low residual turbidity (6.8 NTU). It is believed that this adsorption–flotation technique, here named adsorptive particulate flotation, using activated and modified natural zeolite has a high potential as an alternative for pollutants removal (copper and isopropylxanthate ions) from waste mining effluents.  相似文献   

Thermo-optical detection of defects and decarbonation in natural smithsonite     

Javier Garcia-Guinea  E. Crespo-Feo  V. Correcher  J. Rubio  M. V. Roux  P. D. Townsend 《Physics and Chemistry of Minerals》2009,36(8):431-438

Natural hydrothermal ZnCO₃ crystal aggregates are nominally anhydrous phases with interfacial water, with substitutional divalent cations and decarbonation c. 300°C. All these common features must be involved during the experimental heating of a thermoluminescence (TL) glow curve up to 500°C: dehydration–dehydroxylation, phase transition and ion transition of point defects in Zn²⁺ positions. A representative specimen of natural smithsonite was analysed by X-ray fluorescence spectrometry, field emission scanning electron microscopy (FESEM) with a chemical probe of energy dispersive spectrometer, high temperature in situ X-ray diffraction, differential scanning calorimetry, differential thermal analyses coupled to thermogravimetry, TL, radioluminescence and high resolution spectra thermoluminescence (3DTL), to gain an overview of the spectra emission and defects linkages modified by heating from room temperature up to 500°C. The ZnCO₃ specimen contains minor amounts of Ca, Cu, Cr, Cd, Pb, Ce, Co, Ni, Mn and Fe. Under FESEM, it displays CaCO₃ clusters and oscillatory zoning distribution with lamellae ranging from Ca_0.11Zn_0.89 to Ca_0.19Zn_0.81. The analytical results suggest assignments of defects and processes to measured 3DTL emission bands, as follows: (1) peak at ~260°C, ~360 nm bonds, breaking during the thermal decarbonation process; (2) peak ~120°C, ~340 nm: non-bridging oxygen centres associated to a complex dehydration–dehydroxylation process and (3) peak at ~170°C, ~650 nm, crystal field effects on the thermoluminescence of Mn²⁺ centres and associated transitional elements in the ZnCO₃ phase. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Interplay between detrital and diagenetic processes since the last glacial maximum on the northwest Iberian continental shelf     

Kais Jacob Mohamed  Daniel Rey  Belen Rubio  Federico Vilas  Thomas Frederichs 《Quaternary Research》2010,73(3):507-520

Integrated analyses of magnetic, geochemical and textural data on six cores from the northwestern Iberian continental shelf allowed the reconstruction of the paleoenvironmental evolution of this area since the last glacial maximum (LGM). Four sedimentary units were identified, representing a succession from fluvial and subaerial settings to high and finally low-energy marine deposits subsequent to the post-LGM sea-level rise. The uppermost unit was deposited during the Holocene and its magnetic properties were controlled by the interplay between detrital input and early diagenetic reductive dissolution of magnetic minerals. Identification of a primary steady-state early diagenetic signal allowed the recognition of periods of increased detrital input, bounded by intervals of lower detrital input and intensified reductive diagenesis related to intensified upwelling in the area. These paleoenvironmental alternations are consistent with the climatic evolution of the late Holocene. During the Roman Warm Period and Medieval Warm Period, the combined effect of greater humidity and intense agricultural and mining activities led to a greater erosion and transport of detrital sediments to the shelf. In contrast, enhanced diagenetic reduction intervals, caused by upwelling intensification, were roughly coincident with the colder Dark Ages and the Little Ice Age.  相似文献   

DAF–dissolved air flotation: Potential applications in the mining and mineral processing industry     

Rafael Teixeira Rodrigues  Jorge Rubio 《International Journal of Mineral Processing》2007

Conventional and non-conventional flotation for mineral processing and for water (and wastewaters) treatment and reuse (or recycling) is rapidly broadening their applications in the mining field. Conventional flotation assisted with microbubbles (30–100 μm) finds application in the recovery of fine mineral particles (< 13 μm) and flotation with these fine bubbles is being used as a solid/liquid separation to remove pollutants. The injection of small bubbles to conventional coarse bubbles flotation cells usually leads to general improvements of the separation parameters, especially for the ultrafines (< 5 μm) ore particles. Results obtained are believed to occur by enhancing the capture of particles by bubbles, one of the main drawbacks in fine ore flotation. It is believed that by decreasing the bubble size distribution (through the injection of small bubbles), increases the bubble surface flux and the fines capture. DAF or dissolved air flotation with microbubbles, treating water, wastewater and domestic sewage is known for a number of years and is now gradually entering in the mining environmental area. This technology offers, in most cases, advantages over settling, filtration, precipitation, or adsorption onto natural and synthetic adsorbents. The targets are the removal of oils (emulsified or not), ions (heavy metals and anions) and the reuse or recirculation of the process waters. Advantages include better treated water quality, rapid start up, high rate operation, and a thicker sludge. New applications are found in the mining vehicles washing water treatment and reuse, AMD (acid mining drainage) neutralization and high rate solids/water separation by flotation with microbubbles. This work reviews some recent applications of the use of microbubbles to assist the recovery of very small mineral particles and for the removal of pollutants from mining wastewaters. Emphasis is given to the design features of innovative devices showing the potential of conventional and unconventional DAF flotation.  相似文献   

Interacting tectonics,hydrogeology and karst processes in an intramontane basin: the Jiloca graben (NE Spain)   总被引：1，自引：0，他引：1  

José C. Rubio  José L. Simón  M. A. Soriano 《Hydrogeology Journal》2007,15(8):1565-1576

The Jiloca basin is a NNW–SSE trending, Neogene-Quaternary graben in NE Spain, bounded by normal faults with measurable hectometre-scale throws. Its overall trend truncates previous NW–SE folds. The sedimentary infilling includes Neogene and Quaternary deposits, exceeding 80 m in thickness. The stratigraphical and structural setting controls hydrogeology of the basin. Neogene marls constitute an aquiclude that separates a main Jurassic karstic, confined aquifer from a shallow, unconfined Plio-Quaternary aquifer. The Jurassic aquifer is laterally compartmented by impervious Upper Triassic anticline cores, though its piezometric surface usually lies 30–60 m higher than the Mesozoic-Neogene boundary. The geological, and specifically the hydrogeological features are not significantly compatible with a previously published hypothesis that considers the Jiloca depression as a polje (in which the final topography is the result of suballuvial karstic corrosion) for three reasons. First, the hypothetical corrosion front shows neither a specific relationship with the epiphreatic zone, nor control by the local presence of impervious Triassic rocks. Second, chemistry of groundwater at the underlying Jurassic aquifer would not allow limestone dissolution at rates necessary for producing the supposed erosion deepening of 300 m since the late Pliocene. Finally, no evidence of swallow holes or ponors has been found.  相似文献   

Hydrogeological Investigation of Hydrocarbon Contamination of Ground Water in Albolote (Granada, Spain)     

J. Cruz-Sanjulián  M. Olías  M. del  Valle  J.C. Rubio 《Ground Water Monitoring & Remediation》1992,12(3):188-194

In July 1988, hydrocarbons were detected in wells in the urban area of Albolote, near Granada, Spain, near the border of the "Vega de Granada" alluvial aquifer. According to available hydrogeological data, the contamination was attributed to leaks in the underground pipelines of a nearby (300m) industrial factory, where the loss of 40,000 to 50,000 liters of gasoline had been detected some weeks before. A complete hydrogeological investigation was then undertaken, involving, among other techniques: (a) an inventory of the existing wells in the area; (b) the preparation of piezometric maps; (c) the application of electrical geophysical methods; (d) the drilling of piezometers and new pumping wells between the urbanized area and the leak point; (e) the improvement of the pluviometric and piezometric control by the installation of a pluviograph and several limnigraphs; (f) the sampling, initially daily and finally weekly, in a 20-well observation network, also used for piezometric control; and (g) the geostatistical study of the analytical data. The contamination plume, extended in the direction of the flow lines, has a length of 500m and a width of less than 50m, and appears to have occurred mainly in a paleochannel. Hydrocarbons (1600 liters) were recovered by pumping and by using absorbent blankets, as well as by a gas and liquid suction method. Hydrocarbon concentrations have continuously decreased. However, sporadic increases, associated with rainfall, have been observed suggesting the presence of retained hydrocarbons in the unsaturated zone. The rate of decrease in hydrocarbon concentrations has currently slowed, particularly in the less affected zone. As a means of activating the cleaning up of the unsaturated zone, an artificial recharging method has been designed.  相似文献   

Plinian eruptions of Nevado de Toluca volcano,Mexico     

Dr. K. Bloomfield  G. Sanchez Rubio  Dr. L. Wilson 《International Journal of Earth Sciences》1977,66(1):120-146

Zusammenfassung Die Unteren und die Oberen Bimssteine des Toluca sind dacitische air fall-Ablagerungen, die vor etwa 24 500 bzw. 11 600 Jahren gefördert wurden. Der Lower Toluca Pumice bedeckt ungefähr 400 km2 und hat ein Volumen von rund 0,33 km³ (porenfrei gerechnet von 0,16 km³). Nach der 10-cm-Mächtigkeitskurve zeigt er einen nordostgerichteten Verbreitungsfächer. Der Upper Toluca Pumice bedeckt mehr als 2000 km²; sein Volumen beträgt rund 2,3 km³, wenn man die 40-cm-Mächtigkeitskurve zugrundelegt. Das Gesamtvolumen dürfte bei 3,5 km³ (porenfrei gerechnet bei 1,54 km³) liegen. Sein symmetrischer Verbreitungsfächer hat die Richtung N 65° E.Die INMAN-Parameter, Median (Md) und Sortierung (), zusammen mit dem Zerkleinerungs-Index von granulometrischen Analysen aus 23 Bimssteinprofilen zeigen, daß beide Ausbrüche dem plinianischen Typ zuzuordnen sind. Die Korngrößen-Verteilung, verglichen mit einem einfachen mathematischen Modell, gibt einen annähernden Hinweis auf den Ausbruchsverlauf während der Ablagerung der gröbsten Anteile des unteren Teils der Upper Toluca Pumice-Serie. Nach Berechnungen ergibt sich eine Anfangsgeschwindigkeit der Eruption von 500 m/sek aus einem annähernd runden Schlot mit einem Durchmesser von 260 m, sowie eine horizontale Durchschnittswindgeschwindigkeit von 16,2 m/sek und eine Höhe der Eruptionswolke von 40 km. Die freigewordene kinetische Energie betrug rund 6 X 10¹⁹ erg/sek. Die jüngere Eruption dagegen hatte zehnmal mehr kinetische Energie als die ältere.

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The Lower and Upper Toluca Pumice Formations are dacitic airfall deposits that were erupted about 24,500 yr BP and 11,600 yr BP respectively. The Lower Toluca Pumice covers about 400 km², with a volume of 0.33 km³ (dense rock equivalent 0.16 km³) within the 10 cm isopach, and has a northeast-trending dispersal fan. The Upper Toluca Pumice covers more than 2,000 km², has a volume of 2.3 km³ within the 40 cm isopach, and an estimated total volume of 3.5 km³ (dense rock equivalent 1.54 km³). Its symmetrical dispersal fan trends N 65° E. The Inman parameters, median diameter (Md) and deviation (), together with the fragmentation indices, derived from granulometric studies of samples from 23 pumice sections, show that both eruptions were of Pliniantype. The particle-size distribution, compared with a simple mathematical model of a Plinian eruption, provides an approximate indication of the eruptive conditions during the deposition of the coarsest part of the Lower Member of the Upper Toluca Pumice. Computations give a muzzle velocity of 500 m/sec from a circular vent 260 m in diameter, a mean horizontal windspeed of 16.2 m/sec and an eruptive cloud 40 km high, with a maximum rate of release of kinetic energy of 6 × 10¹⁹ erg/sec. The younger eruption released about ten times more kinetic energy than the older.

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Resumen Las formaciones »Lower y Upper Toluca Pumice« son depósitos de caida libre, originados hace approximadamente 24,500 y 11,600 años A.P., respectivamente. El depósito »Lower Toluca Pumice« cubre un area de aproximadamente 400 km², y tiene un volumen de 0.33 km³ (0.16 km³ de roca masiva) dentro de la isopaca de 10 cm, y su area de dispersión se prolonga en dirección N.E. El depósito »Upper Toluca Pumice« cubre más de 2,000 km², tiene un volumen de 2.3 km³ dentro de la isopaca de 40 cm, y un volumen total estimado en 3.5 km³ (1.54 km³ de roca masiva); su dirección principal de dispersion es N 65° E. Considerando los parámetres de Inman; es decir, diámetro medio (Md) y desviación estandard (), además de los índices de fragmentatión, derivados todos de estudios granulométricos de muestras tomadas en 23 secciones en el campo, ambos depósitos se deben a erupciones del tipo Pliniano. La distribución de tamaños, comparada con un modelo matemático simple de una erupción tipo Pliniano, muestra los parámetres aproximados de la erupción al momenta de depositarse la fracción más gruesa del miembro inferior del depósito »Upper Toluca Pumice«. Los cálculos dan una velocidad de escape de 500 m/seg de un cráter circular 260 m de diámetro, una velocidad media del viento de 16.2 m/seg y una columna eruptiva de 40 km de altura, con un gasto máximo de energía cinética de 6 × 10¹⁹ ergios/seg. La energía cinética liberada por la última erupción fue diez veces mayor que la primera.

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Résumé Les formations inférieures et supérieures de Ponce de Toluca sont des dépôts dacitiques d'origine aérienne, qui ont été émis il y a environ 24,500 ans AP et 11,600 ans AP respectivement. Le »Lower Toluca Pumice«, qui couvre environ 400 km², avec un volume de 0.33 km³ (équivalent à 0.16 km³ de roche compacte) dans I'isopaque de Pumice«, couvre plus de 2000 km², a un volume de 2.3 km³ dans l'isopaque de 40 cm, et un volume global estimé à 3.5 km³ (équivalent à 1.54 km³ de roche compacte). Son éventail symétrique de dispersion est dirigé vers N 65° E. Les paramètres Inman, le diamètre médian (Md) et la déviation (), comme aussi les indices de fragmentation tirés des études granulométriques d'échantillons de 23 profils de ponce, montrent que ces deux éruptions étaient du type plinien. La distribution granulométrique des particules comparée à un modèle mathématique simple d'une éruption plinienne, fournit une indication approximative des conditions d'éruption pendant le dépôt de la fraction la plus grossière du membre inférieur du »Upper Toluca Pumice«. Des calculs donnent une vitesse initiale de 500 m/sec à partir d'un évent circulaire de 260 m de diamètre, une vitesse horizontale de vent de 16.2 m/sec et une nuée éruptive de 40 km de hauteur, avec une degré maximum de libération d'énergie cinétique de 6 × 10¹⁹ erg/sec. L'éruption plus récente a libéré environ dix fois plus d'énergie cinétique que l'éruption plus ancienne.

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, 24500 11600 . «Lower Toluca Pumice» 400 ² 0,33 ³, , — 0,16 ³. 10 , - . «Upper Toluca Pumice» , 2000 ²; 2,3 ³, 40 . 3,5 ³, 1,54 ³. 65°. INMAN, (Md Ø) 23 , . «Upper Toluca Pumica». 500 /, 260 , 16,2 /. 40 . 6&#x0445;10¹⁹ /. 10 , .

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