Análise das características apresentadas em imagens multiespectrais do satélite LANDSAT no mapeamento geológico-estrutural da porção centro-oeste do escudo Sul-Riograndense / Analysis of the characteristics appearing in LANDSAT multispectral images in the geological structural mapping of the midwestern portion of the Rio Grande do Sul shield

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

25/03/1982

RESUMO

The central-western part of Rio Grande do Sul Shield (limited by coordinates 30°00 to 31°30 South and 52°45 to 54°30 West) was geologically mapped to test the use of MSS-LANDSAT data in the study of mineralized regions. The visual interpretation of the images at the seale of 1:500,000 consisted, basically, in the identification and analysis of the different tonal and textural patterns in each spectral band. After the structural geologic mapping of the area, using visual interpretation techniques, the statistical data obtained were evaluated, specially data concerning size and direction of fractures. Furthermore, the multiespectral Imaqe Analyser (IMGE-100 System) was used to enlarge (up to 1:100,000) and to enhance the areas of Lavras do Sul, Minas do Camaquã and Passo do Marinheiro, using Contrast Stretching and Principal Components programmes. In eonclusion, it can be stated that MSS-LANDSAT data offer several advantages over conventional white and black aerial: photographs for geological studies, namely: a) its multispectral characteristic (band 6 and false-colour composition of bands 4, 5 and 7 were best suitable for the purposes of this study); b) coverage of a large imaging area of about 35,000 km$^2$, giving a synoptical view, very useful to pereeive the regional geological setting. Finally one can conclude that, even in areas geologically well known, like the Rio Grande do Sul Shied, MSS-LANDSAT data can be very useful to improve structural geologic information.

ASSUNTO(S)

geologia rio grande do sul (estado) escudo sul-riograndense lavras do sul (rs) minas do camaquã (rs) passo do marinheiro (rs) imagens multiespectrais propriedades estruturais (geologia) mapeamento geológico sistemas multiespectrais de varredura imagens landsat satélites landsat geology multispectral imagery geological mapping structural properties (geology)

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