Avaliacao de dados aerogamaespectrometricos e de sua integracao com imagens digitais TM/Landsat 5, no mapeamento geologico na Serra dos Carajas (PA) / Evaluation of aerogammaspectrometric data and their integration with Landst-TM digital images for geological mapping in the Serra dos Carajas (PA)

AUTOR(ES)
DATA DE PUBLICAÇÃO

1994

RESUMO

Two test-sites, covering the Serra dos Carajás sheet (56,5 x 56,5 kin) and the Pojuca belt (15,4 x 15,4 kin) were selected for geological investigation. Gammaspectrometric airborne data (eU, eTh, Total Count and eU/eTh) were acquired over part of the Serra dos Carajfis Mineral Province (Brazilian Amazon Region) during the 1975 and 1976 (PGBC - Brazil-Canada Geophysical Program) campaigns. The original data were collected in NS profiles (1 km apart and 61 meter samples along the profiles). The gammaspectrometric data were converted twice, first to a 625 x 625 m grid and then to a 125 x 125 m grid (resampling). The 125 x 125 m data were transformed into digital images with cells of 125 x 125 m and 30 x 30 m. Isolated and combined gamma images were analysed by digital enhancement techniques (color composites, principal component, analysis decorrelation stretch and IHS transform) and visual examination. The UTM registered gamma and TM/Landsat images were integrated through IHS transform. The enhanced products were compared to geological maps and this comparition has demonstrated that lithostratigraphic units and structural features registered on both data source are perfectly concordant. In addition, the research has provided insights regarding the knowledge of the geological model in the study areas. Gamma airborne data whether isolated or integrated with orbital remote sensing data have proved to be a powerful tool for geological mapping and mineral exploration programs in this rain forest Amazon environment.

ASSUNTO(S)

processamento digital de imagens landsat-5 geologia geology temathic mappers (landsat) mapeador tematico (landsat) satelites landsat image processing serra dos carajas (pa)pojuca (pa) mapeamento geologico

ACESSO AO ARTIGO

Documentos Relacionados