%0 Journal Article
%4 sid.inpe.br/iris@1912/2005/07.20.05.14
%2 sid.inpe.br/iris@1912/2005/07.20.05.14.19
%@issn 1516-697X
%F 1068
%T Remote detection of a tonal anomaly in area of hydrocarbon microseepage, Tucano basin, north-eastern Brazil
%D 1999
%8 Sep.
%9 journal article
%A Almeida Filho, Raimundo,
%A Miranda, Fernando Pelon de,
%A Yamakawa, Tadashi,
%@affiliation National Institute for Space Research-INPE, Caixa Postal 515
%@affiliation Petrobras/CENPES, Cidade Univcrsitária, Ilha do Fund̃o, Q-7, Rio de Janeiro-RJ, Brazil
%@affiliation Earth Resources Satellite Data Analysis Center-ERSDAC 3-12-1, Kachidoki Chuo-Ku, Tokyo 104, Japan
%B International Journal of Remote Sensing
%V 20
%N 13
%P 2683-2688
%K Gamma rays, Geochemistry, Hydrocarbons, Magnetic susceptibility, Radioactivity, Seepage, Hydrocarbon microseepage, Landsat-Thematic mapper, Radioactivity intensity, Soil gas, Tonal anomaly.
%X Mapping of a tonal anomaly in an area of hydrocarbon microseepage was possible using a Landsat-Thematic Mapper false-colour composite consisting of TM2/3, TM4/3 and of the difference TW.3-TM4/3, displayed as red, green and blue respectively. In this false-colour composite, green and yellow express variations in the vegetation cover, whereas hues of magenta are related to terrain conditions representing bleached materials, which occur close to the centre of a soil gas anomaly. Simultaneous occurrence of anomalous soil gas values with magnetic and radioactive minerals suggests that a reducing environment associated with the microseepage phenomenon created the bleached materials, identified as a tonal anomaly in the enhanced TM image.
%@language en
%3 raimundo6.pdf