%0 Journal Article
%4 sid.inpe.br/iris@1912/2005/07.21.00.38.01
%2 sid.inpe.br/iris@1912/2005/07.21.00.38.05
%@doi 10.1080/01431160210137695
%@issn 0143-1161
%F 10213
%T Terrain characteristics of a tonal anomaly remotely detected in an area of hydrocarbon microseepage, Tucano Basin, north-eastern Brazil
%D 2002
%8 Sep.
%9 journal article
%A Almeida Filho, Raimundo,
%A Miranda, Fernando Pelon,
%A Galvão, Lênio Soares,
%A Freitas, Corina da Costa,
%@affiliation
%@affiliation Petrobras/CENPE Cidade Universitária, Ilha do Fundão, Q-7, Rio de Janeiro-RJ, Brazil
%B International Journal of Remote Sensing
%V 23
%N 18
%P 3893-3898
%K : Geochemistry, Hydrocarbons, Magnetic susceptibility, Radioactivity, Seepage, Soils, Soil spectra absorption band, Remote sensing, anomaly, hydrocarbon, image classification, Landsat thematic mapper, remote sensing, seepage, Brazil.
%X This study reports the geological characteristics of a tonal anomaly in an area of hydrocarbon microseepage, identified in Landsat-5 Thematic Mapper (TM)images. A diversified dataset was gathered, which included soil gas geochemistry determinations, soil radioactivity intensity and soil magnetic susceptibility measurements, as well as laboratory soil spectra. Data indicated that the tonal anomaly holds a higher concentration of gaseous hydrocarbons in soils than the surroundings, accompanied by enrichment in radioactive minerals. However, there is no definitive evidence of magnetic mineral enrichment inside the tonal anomaly compared with the surroundings. An intense silicification process, characterized by a cover of fine-grained silicified cobbles and boulders, seems to be responsible for inhibiting the development of diagenetic clay mineralization, as indicated by variations in the depth of the 2200 nm soil spectra absorption band.
%@language en
%3 INPE 9069.pdf