Browsing by Issue Date, starting with "2011-07"
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- Heat as by-product or sub-product of CO2 storage in mafic and ultramafic rocksPublication . Rosa, Diogo; Rosa, Rui
- Pre-meeting field trip Southern Iberia Traverse (29th June to 4th July 2011) : OverviewPublication . González Menéndez, Luis; Solá, A. Rita; Azor, Antonio
- Climate changes in the Western Iberian Margin during Marine Isotope Stages 15-9, 580 to 300 : suborbital glacial variabilityPublication . Rodrigues, Teresa; Abrantes, Fátima; Voelker, Antje H. L.; Grimalt, Joan O.; Naughton, Filipa
- The Berlengas Archipelago granitoids within the frame of the Variscan Orogeny, W Portugal : new data and insightsPublication . Valverde-Vaquero, Pablo; Bento dos Santos, Telmo; González Clavijo, Emilio José; Díez-Montes, Alejandro; Ribeiro, Maria Luísa; Solá, A. Rita; Silva, I. Dias da
- New geochemical and geochronological data of early Cambrian of SW Iberia : calc-alkaline magmatism in the transition from active to passive continental margin in North GondwanaPublication . Sánchez-García, T.; Pereira, Manuel Francisco Costa; Bellido Mulas, F.; Chichorro, Martim; Silva, J. Brandão; Valverde-Vaquero, Pablo; Pin, C.; Solá, A. Rita
- Prospecção de rochas ornamentaisPublication . Carvalho, JorgeAs rochas ornamentais podem ser entendidas como a matéria-prima mineral utilizada como material de construção com funções essencialmente decorativas. São um recurso geológico que ano após ano tem vindo a ganhar importância económica mas cuja exploração tem sido feita, na maior parte dos casos, com base em conhecimentos empíricos. Mesmo perante os crescentes constrangimentos de acessibilidade territorial aos recursos, pouco se tem investido na inovação das metodologias de prospecção e avaliação de jazidas de rochas ornamentais. Estando a ocorrência e localização desses depósitos dependente unicamente de factores geológicos, as metodologias para a sua revelação e avaliação deverão basear-se em critérios também eles de índole geológica. Enfatiza-se neste trabalho a cartografia geológica e o estudo da fracturação dos maciços rochosos como ferramentas fundamentais à avaliação dos critérios de carácter decisivo na prospecção de rochas ornamentais. Estes relacionam-se unicamente com o dimensionamento e homogeneidade das unidades geológicas e seu estado de fracturação.
- Prídolí graptolites in the Amêndoa-Carvoeiro Synform (SW border of the Central Iberian Zone, Portugal) : biostratigraphical relevancePublication . Piçarra, José Manuel; Romão, José
- Granitic magmatism along the Central Iberian/Ossa Morena Zone boundary (SW Iberia) : geochronology, composition, and geodynamic significancePublication . Solá, A. Rita; Ribeiro, Maria Luísa; Neiva, A.M.R.
- Variability during Marine Isotope Stages 11, 13 and 15 as revealed at IODP Sites U1313 and U1305, North AtlanticPublication . Voelker, Antje H. L.; Ventura, Cristina; Cavaleiro, Catarina; Rebotim, Andreia; Hillaire-Marcel, Claude; De Vernal, Anne; Martin, Pamela A.
- Comparison of calibration of hyperspectral image-processing techniques for environmental assessment in S. Domingos Mine, SE PortugalPublication . Quental, Lídia; Sousa, António Jorge Gonçalves de; Marsh, Stuart HarryABSTRACT: This study addresses the application of hyperspectral or imaging spectroscopy (IS) sensors to environmental concerns related to mining areas and is tested in the old S. Domingos Mine. To detect for acid mine drainage a multi-source spectral methodology was developed based on distinct spectra: mineralogical libraries, field, and endmembers extracted from the images. A quantitative link is established among them, selecting the highest correlation values as input spectra for the Spectral Angle Mapper algorithm, generating two maps in function of either field or endmembers spectra. The final improved map is the pixel intersection of both, converted to high spectral correlations of mineralogical assemblages indicators of low pH (<3)[copiapite(coquimbite)(smectite-alunite-illite-kaolinite)]. The low pH areas vary in function of the atmospheric corrections and the thresholds selected, but generally assign the same critical hazardous areas in year 2000. The monitoring capabilities were tested with another IS sensor seven years apart (2007) but the same methodology did not yield significant results, highlighting the complexity of a multi-sensor approach. The translation of input IS data resampled to a contemporary multispectral image mapped similar areas of low pH and opens good perspectives for multispectral routine application, once at some stage multi-source IS knowledge is available on a site.
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