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The use of GPR and VES in delineating a contamination plume in a landfill site: a case study in SE Brazil 总被引:3,自引:0,他引:3
Jorge L. Porsani Walter M. Filho Vagner R. Elis Fisseha Shimeles Joo C. Dourado Helyelson P. Moura 《Journal of Applied Geophysics》2004,55(3-4):199-209
This paper presents the results of the application of the Ground Penetrating Radar (GPR) method, or Georadar, in outlining a zone of contamination due to solid residues at the waste burial site of Rio Claro in the state of São Paulo, SE Brazil. A total of eight GPR profiles with 50- and 100-MHz antennae were surveyed. Six profiles were located within the landfill site and the remaining two were outside. The main objective of the GPR survey was to evaluate the side extension of contamination. A Vertical Electric Sounding (VES) survey was performed at four points within the site in order to investigate the vertical extent of the contamination plume and to define the bottom of the landfill. Two additional VESs were done outside the landfill with the purpose of determining the top of the ground water table and the geoelectric stratigraphy of the background. From the interpretation of the GPR profiles, it was possible to locate the top of the contamination plume and to infer that it was migrating laterally beyond the limits of the waste disposal site. This was observed along the profile situated close to the highway SP-127, which was about 20 m from the limit of the site. The signature of the contaminant appears as a discontinuous reflector that is believed to be a shallow ground water table. The discontinuity is marked by a shadow zone, which is characteristic of conductive contaminant residues. The contamination did not move far enough to reach a sugar cane plantation located at approximately 100 m from the border of the site. In the regions free from contamination, the ground water table was mapped at approximately 10 m of depth, and it was characterized by a strong and continuous reflector. The radar signal penetrated deep enough and enabled the identification of a second reflector at approximately 14 m deep, interpreted as the contact between the Rio Claro and the Corumbataí formations. The contact is marked by the presence of gravel characterized by ferruginous concretes, which cause the strong amplitude reflection in the GPR profile. Within the landfill site, the quantitative interpretation of the VES results showed the contamination zone. The base of the landfill varies between 11 and 15 m deep. Outside the landfill site, the VES results showed no indication of contamination and allowed the determination of the top of the ground water table and the contact between the Rio Claro and the Corumbataí formations. The results of GPR and VES showed a good agreement and the integrated interpretations were supported by local geology and information from several boreholes, about 17 m depth, on average. The bottom of the landfill reaches a maximum of 14.5 m depth. 相似文献
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I.P. Guimarães A.F. Silva Filho C.N. Almeida M.B. Macambira R. Armstrong 《Journal of South American Earth Sciences》2011,31(4):383-396
The Tabira, Itapetim and Timbaúba granitoids are intruded into metasedimentary sequences and Cariris Velhos (Tonian) orthogneisses from the Central Domain of the Borborema Province, NE Brazil. They have U–Pb SHRIMP ages of 593 ± 7 Ma; 615 ± 9 Ma and 616 ± 5 Ma respectively. The studied granitoids have zircon cores inherited from the protholith, with a large number of analyses showing 206Pb/238U ages ranging from 950 to 1200 Ma. Oscillatory zoning typical of magmatic zircon is common, although it is faint in some inherited cores.The studied granitoids are calc-alkaline and show Nd TDM model ages ranging from 1.30 to 1.56 Ga and ?Nd (600 Ma) ranging from ?2.40 to ?5.34. These values are similar to those recorded in the country rocks. The lowest values of ?Nd (600 Ma) were recorded in enclaves of dioritic composition. Nd and U–Pb SHRIMP data suggest a significant participation of the metasedimentary rocks in the protholith of these granitoids. The Mesoproterozoic Nd TDM model ages recorded in the studied granitoids are interpreted as the result of a hybrid source involving melting of metagraywackes, metamafic rocks of Tonian ages and/or biotite – bearing orthogneisses (Cariris Velhos Orthogneisses). The resulted melting was modified by mingling with juvenile Brasiliano melts, diorite in composition.The Timbaúba granitoids intrusions are coeval with high-T metamorphism and flat-lying foliation forming event in an intracontinental setting, during the Brasiliano convergence and contractional deformation. The Itapetim Pluton was emplaced in the convergence - lateral escape setting and the Tabira granitoids were intruded after the flat-lying foliation event, representing sin transcurrent intrusions.Our data show that within the Central Domain of the Borborema Province, granitoids with similar petrographic and geochemical compositions can have distinct ages and be intruded in distinct tectonic regimes. 相似文献
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Filho Hugo Carlos Scheuermann Martins Carlos Guilherme Menezes Ricardo José Wink Dornelles Lucas Eduardo Consoli Nilo Cesar 《Geotechnical and Geological Engineering》2021,39(7):5395-5404
Geotechnical and Geological Engineering - Dispersive soils are susceptible to phenomena of internal and external erosion when in contact with relatively pure water due to its particle’s... 相似文献
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M.A. Dardenne C.F. Ferreira Filho M.R. Meirelles 《Journal of South American Earth Sciences》1988,1(4)
In the Carajás District, the Bahia Prospect and Grão Pará volcanosedimentary sequences, both of Archean age, have been the object of extensive petrochemical studies for major, trace, and rare earth elements. In spite of the widespread spilitization that affected the volcanic mafic rocks, the petrochemical nature of the mafic volcanism may still be assessed on the basis of the less mobile elements like P, Cr, Zr, Nb, Ti, and REE. The Bahia Prospect basalts have a petrochemical affinity with Phanerozoic island-arc calc-alkaline basalts. The Grão Pará basalts and basaltic andesites, on the other hand, have a petrochemical affinity with Phanerozoic basalts of a mature island arc environment. The petrochemical data presented here lead to a new geotectonic interpretation of the area, where the volcanic sequences are genetically linked to Archean subduction processes. 相似文献
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H. de Almeida Sampaio Filho G. P. Sighinolfi E. Galli 《Contributions to Mineralogy and Petrology》1973,38(4):279-290
Chemical analyses and crystallographic and some optical data have been obtained for 28 samples of beryl from Bahia State, Brazil. The larger range of variability in the chemical composition is shown by Mg, Fe and Li. Sodium is the more diffuse alkali element. Potassium is always very limited. Calcium appears in noticeable amounts only in three samples. The Ti, Cr, Rb, and Cs elements were also tested. The samples studied here can be defined as sodium-potassium beryls with low alkali content. Unit cell parameters show the following ranges: a=9.210–9.245 and c=9.190–9.220 Å. From a statistical analysis of these data it may be seen that: an increase of Fe and (Fe+Mn+Mg) percentage has a positive correlation with a, but no influence on c, which in turn has a close positive correlation with Li and is negatively correlated with Be. Less negative correlations also exist between the pairs {Be, Li}, {a,Al}, {Al, Fe} and {Al, (Fe+Mn+Mg)}. A positive correlation also exists between sodium and the parameter a. 相似文献
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