Two-dimensional interpretation of three-dimensional magnetotelluric data: an example of limitations and resolution   总被引：7，自引：1，他引：7  

Juanjo Ledo  Pilar Queralt  Anna Martí  Alan G. Jones 《Geophysical Journal International》2002,150(1):127-139

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Reconnaissance geology in Upper Chitral,Baroghil and Karambar districts (northern Karakorum,Pakistan)     

Maurizio Gaetani  Lucia Angiolini  Alda Nicora  Dario Sciunnach  Patrick Le Fort  Seifnullah Tanoli  Asif Khan 《International Journal of Earth Sciences》1996,85(4):683-704

During the summer of 1992 a geological expedition crossed the northern Karakorum range in northern Pakistan, from the Chitral to Karambar valleys, from the villages of Mastuj to Imit. Some of the areas visited were geologically unknown. A number of structural units were crossed, belonging to the Karakorum block or to other crustal blocks north of it. They are: (a) the axial batholith, in which three plutonic bodies have been identified, and (b) the northern sedimentary belt (NSB), in which three major tectonostratigraphic units form thrust stacks dipping to the north. Their internal stratigraphy and structural style are partly different. The most complete contains a crystalline basement, transgressed by a marine succession during the Early Ordovician. The youngest strata are represented by the Reshun conglomerate, of inferred Cretaceous age. The northernmost unit of the NSB is tightly folded, whereas the central one forms a monocline. Vertical faults, mainly strike-slip, dissect the thrusted slabs. Metamorphic deformation is absent or reaches only the anchizone in the studied sector of the Karakorum NSB. To the north of the Karakorum proper there are several other tectonic units, separated by vertical faults. They are, from south to north: (a) the Taš Kupruk zone, with metavolcanics of basaltic to latibasaltic composition; (b) the Atark unit, mostly consisting of massive carbonate rocks of Mesozoic age; and (c) the Wakhan slates which consist of a thick widespread succession of dark slates, metasiltites and sandstones. The fine-grained elastic rocks are supposed to be Palaeozoic to Early Triassic in age. The Wakhan slates are intruded by plutons belonging to the East Hindu Kush batholith, from which a single K/Ar age on muscovite gave a Jurassic age.  相似文献   

Horizontal and vertical variability of soil properties in a trace element contaminated area     

Pilar Burgos  Engracia MadejónAlfredo Pérez-de-Mora  Francisco Cabrera 《International Journal of Applied Earth Observation and Geoinformation》2008

The spatial distribution of some soil chemical properties and trace element contents of a plot affected by the Aznalcóllar mine spill were investigated using statistical and geostatistical methods to assess the extent of soil contamination. Total and EDTA-extractable soil trace element concentrations and total S content showed great variability and high coefficients of variation in the three examined depths. Soil in the plot was found to be significantly contaminated by As, Cd, Cu, Pb and Zn within a wide range of pH. Total trace element concentrations at all depths (0–60 cm) were much higher than background values of non-affected soil, indicating that despite the clean-up operations, the concentration of trace elements in the experimental plot was still high. The spatial distribution of the different variables was estimated by kriging to design contour maps. These maps allowed the identification of specific zones with high metal concentrations and low pH values corresponding to spots of residual sludge. Moreover, kriged maps showed distinct spatial distribution and hence different behaviour for the elements considered. This information may be applied to optimise remediation strategies in highly and moderately contaminated areas.  相似文献   

Recruitment indices of European hake, Merluccius merluccius (Linnaeus 1758), in the Northwest Mediterranean based on landings from bottom-trawl multispecies fisheries     

Goni  Raquel; Adlerstein  Sara; Alvarez  Federico; Garcia  Mariano; Sanchez  Pilar; Sbrana  Mario; Maynou  Francesc; Viva  Claudio 《ICES Journal of Marine Science》2004,61(5):760-773

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Linking Palaeozoic palaeogeography of the Betic Cordillera to the Variscan Iberian Massif: new insight through the first conodonts of the Nevado-Filábride Complex     

Rodríguez-Cañero  Rosario  Jabaloy-Sánchez  Antonio  Navas-Parejo  Pilar  Martín-Algarra  Agustín 《International Journal of Earth Sciences》2018,107(5):1791-1806

International Journal of Earth Sciences - Graphite-rich metamorphic limestones included within low-grade black schists of the lowest Nevado-Filábride tectonic unit in the Sierra de Baza...  相似文献   

New discoveries of mud volcanoes on the Moroccan Atlantic continental margin (Gulf of Cádiz): morpho-structural characterization   总被引：3，自引：3，他引：0  

Ricardo León  Luis Somoza  Teresa Medialdea  Juan Tomás Vázquez  Francisco Javier González  Nieves López-González  David Casas  María del Pilar Mata  María Carmen del Fernández-Puga  Carmen Julia Giménez-Moreno  Víctor Díaz-del-Río 《Geo-Marine Letters》2012,32(5-6):473-488

During the MVSEIS-08 cruise of 2008, ten new mud volcanoes (MVs) were discovered on the offshore Moroccan continental margin (Gulf of Cádiz) at water depths between 750 and 1,600?m, using multibeam bathymetry, backscatter imagery, high-resolution seismic and gravity core data. Mud breccias were recovered in all cases, attesting to the nature of extrusion of these cones. The mud volcanoes are located in two fields: the MVSEIS, Moundforce, Pixie, Las Negras, Madrid, Guadix, Almanzor and El Cid MVs in the western Moroccan field, where mud volcanoes have long been suspected but to date not identified, and the Boabdil and Al Gacel MVs in the middle Moroccan field. Three main morphologies were observed: asymmetric, sub-circular and flat-topped cone-shaped types, this being the first report of asymmetric morphologies in the Gulf of Cádiz. Based on morpho-structural analysis, the features are interpreted to result from (1) repeated constructive (expulsion of fluid mud mixtures) and destructive (gravity-induced collapse and submarine landsliding) episodes and (2) interaction with bottom currents.  相似文献   

Micromorphological analysis of liquefaction features in alluvial and coastal environments of Christchurch,New Zealand     

Monica Giona Bucci  Carol M. Smith  Peter C. Almond  Pilar Villamor  Martitia P. Tuttle 《Sedimentology》2019,66(3):963-982

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Bootstrap approaches for spatial data     

Pilar García-Soidán  Raquel Menezes  Óscar Rubiños 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(5):1207-1219

Generation of replicates of the available data enables the researchers to solve different statistical problems, such as the estimation of standard errors, the inference of parameters or even the approximation of distribution functions. With this aim, Bootstrap approaches are suggested in the current work, specifically designed for their application to spatial data, as they take into account the dependence structure of the underlying random process. The key idea is to construct nonparametric distribution estimators, adapted to the spatial setting, which are distribution functions themselves, associated to discrete or continuous random variables. Then, the Bootstrap samples are obtained by drawing at random from the estimated distribution. Consistency of the suggested approaches will be proved by assuming stationarity from the random process or by relaxing the latter hypothesis to admit a deterministic trend. Numerical studies for simulated data and a real data set, obtained from environmental monitoring, are included to illustrate the application of the proposed Bootstrap methods.  相似文献   

Study of the effect of temperature, irradiance and salinity on growth and yessotoxin production by the dinoflagellate Protoceratium reticulatum in culture by using a kinetic and factorial approach     

Paz B  Vázquez JA  Riobó P  Franco JM 《Marine environmental research》2006,62(4):286-300

A complete first order orthogonal plan was used to optimize the growth and the production of yessotoxin (YTX) by the dinoflagellate Protoceratium reticulatum in culture by controlling salinity, temperature and irradiance. Initially, an approach to the kinetic data of cellular density and YTX production for each one of the experimental design conditions was performed. The P. reticulatum growth and YTX production were fitted to logistical equations and to a first-order kinetic model, respectively. The parameters obtained from this adjustment were used as dependent variables for the formulation of the empirical equations of the factorial design tested. The results showed that in practically all the cases for both, P. reticulatum growth and YTX production, irradiance is the primary independent variable and has a positive effect in the range 50-90 micromol photons m(-2) s(-1). Additionally, in certain specific cases, temperature reveals significant positive effects when maintained between 15 and 23 degrees C and salinity in the range of 20-34 displays negative effects. Despite the narrow ranges used in the work, results showed the suitability of factorial analysis to evaluate the optimal conditions for growth and yessotoxin production by the dinoflagellate P. reticulatum.  相似文献   

On the waterfront: Quaternary environments and the formative occupation of Southwestern Ecuador     

Jonathan E. Damp  Donald Jackson  Patricia Vargas  Pilar Zambrano 《Geoarchaeology》1990,5(2):171-185

The occurrence of tectonic uplift in coastal South American prehistory is discussed and evidence of emerged shoreline features is presented for the area of the Santa Elena Peninsula in Ecuador. It is hypothesized that this activity, once thought to be exclusively Pleistocene in timing, continued on into the Holocene. Given this perspective and field data, the role of the Early Formative Period Valdivia phase (3500-1500 B.C.) site of Real Alto is examined, as is the economic structure of Real Alto society. the pattern of site distribution and data from geological units indicate a long period of tectonic activity that restructured the Ecuadorian coastline and affected northern Andean prehistory. the implications for the origins of Valdivia and New World pottery are reconsidered in light of new information on the Quaternary environments of Ecuador.  相似文献