Sur l'origine par altération du substratum schisteux de la minéralisation chlorurée des eaux d'une nappe côtière sous climat semi-aride (Chtouka-Massa,Maroc)     

Samira Krimissa  Jean-Luc Michelot  Lhoussaine Bouchaou  Jacques Mudry  Youssef Hsissou 《Comptes Rendus Geoscience》2004,336(15):1363-1369

The origin of chloride ions in groundwater from the Chtouka-Massa plain (Morocco) was studied by using chemical and isotopic analyses of water, and petrographic and chemical analyses of rocks. It appears that the schist formation, which forms the basement of the studied aquifer, is the main source of the high Cl^? concentrations in groundwater. In these schists, chloride is, for a part, probably contained in biotites, and is released into groundwater through the weathering of these minerals. However, the exceptionally high chloride contents of these schists are difficult to explain if one does not assume that they also contain evaporitic-type minerals. To cite this article: S. Krimissa et al., C. R. Geoscience 336 (2004).  相似文献   

Kinematic models of deformation at the front of the Alps: new data from map-view restoration     

Thomas Affolter  Jean-Luc Faure  Jean-Pierre Gratier  Bernard Colletta 《Swiss Journal of Geoscience》2008,101(2):289-303

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On the use of long-term observation of water level and temperature along the shore for a better understanding of the dynamics: example of Toulon area,France     

Rey  Vincent  Dufresne  Christiane  Fuda  Jean-Luc  Mallarino  Didier  Missamou  Tathy  Paugam  Caroline  Rougier  Gilles  Taupier-Letage  Isabelle 《Ocean Dynamics》2020,70(7):913-933

Ocean Dynamics - A dense network of instruments has been deployed within harbors along the Mediterranean coast, in the Toulon Metropole area, between the Hyères islands and the Sanary Bay in...  相似文献   

A Bayesian method for missing rainfall estimation using a conceptual rainfall–runoff model     

Siao Sun  Günther Leonhardt  Santiago Sandoval  Jean-Luc Bertrand-Krajewski  Wolfgang Rauch 《水文科学杂志》2017,62(15):2456-2468

The estimation of missing rainfall data is an important problem for data analysis and modelling studies in hydrology. This paper develops a Bayesian method to address missing rainfall estimation from runoff measurements based on a pre-calibrated conceptual rainfall–runoff model. The Bayesian method assigns posterior probability of rainfall estimates proportional to the likelihood function of measured runoff flows and prior rainfall information, which is presented by uniform distributions in the absence of rainfall data. The likelihood function of measured runoff can be determined via the test of different residual error models in the calibration phase. The application of this method to a French urban catchment indicates that the proposed Bayesian method is able to assess missing rainfall and its uncertainty based only on runoff measurements, which provides an alternative to the reverse model for missing rainfall estimates.  相似文献   

Investigations of subsurface flow constructed wetlands and associated geomaterial resources in the Akumal and Reforma regions,Quintana Roo,Mexico     

Mark P. S. Krekeler  Pete Probst  Misha Samsonov  Cynthia M. Tselepis  William Bates  Lance E. Kearns  J. Barry Maynard 《Environmental Geology》2007,53(4):709-726

Subsurface flow constructed wetlands in the village of Akumal, Quintana Roo, Mexico were surveyed to determine the general status of the wetland systems and provide baseline information for long term monitoring and further study. Twenty subsurface flow wetlands were surveyed and common problems observed in the systems were overloading, poor plant cover, odor, and no secondary containment. Bulk mineral composition of aggregate from two subsurface flow constructed wetlands was determined to consist solely of calcite using bulk powder X-ray diffraction. Some soil structure is developed in the aggregate and aggregate levels in wetlands drop at an estimated rate between 3 and 10 cm/year for overloaded wetlands owing to dissolution. Mineral composition from fresh aggregate samples commonly is a mixture of calcite and aragonite. Trace amounts of Pb, Zn, Co, and Cr were observed in fresh aggregate. Coefficients of permeability (k) varied from 0.006 to 0.027 cm/s with an average values being 0.016 cm/s. Grain size analysis of fresh aggregate samples indicates there are unimodal and multimodal size distributions in the samples with modes in the coarse and fine sand being common. Investigations of other geologic media from the Reforma region indicate that a dolomite with minor amounts of Fe-oxide and palygorskite is abundant and may be a better aggregate source that the current materials used. A Ca-montmorillonite bed was identified in the Reforma region as well and this unit is suitable to serve as a clay liner to prevent leaks for new and existing wetland systems. These newly discovered geologic resources should aid in the improvement of subsurface flow constructed wetlands in the region. Although problems do exist in these wetlands with respect to design, these systems represent a successful implementation of constructed wetlands at a community level in developing regions.  相似文献   

Apport des isotopes stables dans l'estimation des altitudes de recharge de sources thermales du MarocRecharge altitude estimation of thermal springs using stable isotopes in Morocco     

Anne Winckel  Christelle Marlin  Laurent Dever  Jean-Luc Morel  Karim Morabiti  Mohamed Ben Makhlouf  Ahmed Chalouan 《Comptes Rendus Geoscience》2002,334(7):469-474

The recharge altitude estimation of thermal springs from northern and eastern Morocco using ¹⁸O and ²H contents requires the definition of regional isotopic altitudinal gradients (?0.25‰ for 100 m for the Rif and ?0.30‰ for the East) and the calculation of residence time using ¹⁴C. The altitudes of emergence vary widely between 170 and 1040 m under the altitude of the recharge areas. The ¹⁸O and ²H compositions of palaeowaters ($\text{>10}\text{000}$ yr BP) indicate two effects, altitude and palaeoclimate. To cite this article: A. Winckel et al., C. R. Geoscience 334 (2002) 469–474.  相似文献   

New Image Modeling Approaches     

Fionn Murtagh  Jean-Luc Starck 《Surveys in Geophysics》2000,21(2-3):229-239

Earth observation relies heavily on imaging. Extraction of informationin turn relies on image processing and analysis. A new and powerfulmethodology has come to the fore in recent years, based on the waveletand other multiscale transforms. Of the many possible application areaswe describe in this paper some approaches for object and feature findingin images', noise filtering of synthetic aperture radar (SAR) images, andthe automatic geometrical registration of different images.  相似文献   

The Teggiolo zone: a key to the Helvetic–Penninic connection (stratigraphy and tectonics in the Val Bavona,Ticino, Central Alps)     

Battista Matasci  Jean-Luc Epard  Henri Masson 《Swiss Journal of Geoscience》2011,104(2):257-283

The Teggiolo zone is the sedimentary cover of the Antigorio nappe, one of the lowest tectonic units of the Penninic Central Alps. Detailed mapping, stratigraphic and structural analyses, and comparisons with less metamorphic series in several well-studied domains of the Alps, provide a new stratigraphic interpretation. The Teggiolo zone is comprised of several sedimentary cycles, separated by erosive surfaces and large stratigraphic gaps, which cover the time span from Triassic to Eocene. At Mid-Jurassic times it appears as an uplifted, partially emergent block, marking the southern limit of the main Helvetic basin (the Limiting South-Helvetic Rise LSHR). The main mass of the Teggiolo calcschists, whose base truncates the Triassic–Jurassic cycles and can erode the Antigorio basement, consists of fine-grained clastic sediments analogous to the deep-water flyschoid deposits of Late Cretaceous to Eocene age in the North-Penninic (or Valais s.l.) basins. Thus the Antigorio-Teggiolo domain occupies a crucial paleogeographic position, on the boundary between the Helvetic and Penninic realms: from Triassic to Early Cretaceous its affinity is with the Helvetic; at the end of Cretaceous it is incorporated into the North-Penninic basins. An unexpected result is the discovery of the important role played by complex formations of wildflysch type at the top of the Teggiolo zone. They contain blocks of various sizes. According to their nature, three different associations are distinguished that have specific vertical and lateral distributions. These blocks give clues to the existence of territories that have disappeared from the present-day level of observation and impose constraints on the kinematics of early folding and embryonic nappe emplacement. Tectonics produced several phases of superimposed folds and schistosities, more in the metasediments than in the gneissic basement. Older deformations that predate the amplification of the frontal hinge of the nappe generated the dominant schistosity and the km-wide Vanzèla isoclinal fold.  相似文献   

Radar detection of Asteroid 2002 AA29     

Steven J Ostro  Jon D Giorgini  Alice A Hine  Jean-Luc Margot  Christian Veillet 《Icarus》2003,166(2):271-275

Radar echoes from Earth co-orbital Asteroid 2002 AA29 yield a total-power radar cross section of 2.9×10⁻⁵ km² ±25%, a circular polarization ratio of SC/OC=0.26±0.07, and an echo bandwidth of at least 1.5 Hz. Combining these results with the estimate of its visual absolute magnitude, H_V=25.23±0.24, from reported Spacewatch photometry indicates an effective diameter of 25±5 m, a rotation period no longer than 33 min, and an average surface bulk density no larger than 2.0 g cm⁻³; the asteroid is radar dark and optically bright, and its statistically most likely spectral class is S. The H_V estimate from LINEAR photometry (23.58±0.38) is not compatible with either Spacewatch's H_V or our radar results. If a bias this large were generally present in LINEAR's estimates of H_V for asteroids it has discovered or observed, then estimates of the current completeness of the Spaceguard Survey would have to be revised downward.  相似文献   

Chemical mass budget of two dredged lakes embedded in shallow Quaternary aquifers in southern Austria     

B. Yehdegho  G. Probst 《Environmental Geology》2001,40(7):809-819

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