Landsat Remote Sensing Data as an Alternative Approach for Geological Mapping in Tanzania: A Case Study in the Rungwe Volcanic Province, South-Western Tanzania
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Date
2011
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Abstract
Rungwe Volcanic Province (RVP) is mostly covered by extrusive rocks that overlain the
Precambrian basement. The use of Landsat data in this area has revealed the need of effective
use of these data in geological mapping programs in Tanzania. Landsat band ratios 5/1, 3/7,
5/7 and 5/4 as well as R: G: B composite images 7:4:1, 7:5:4, 1/3:5/7:3/5 and 4/5:6/7:4/6 played
an important role in identifying different rock types in the study area. Ratio images managed
clearly to distinguish between mafic and felsic rocks whereby two lithological blocks were
identified, Block 1 covers a combination of intrusive and metamorphic rocks while Block 2 is
dominated by extrusive rocks. Composite images went further to the discrimination of individual
lithological units in which different rock types were identified, example phonolitic trachytes,
basalts, tephrites and granitoids. Vegetation overlap problem was cleared up by results from
classification in which the thick vegetated areas were discriminated. Hence, results from Landsat
data analyses showed clear lithological correlation between Landsat images and the available
geological map in the study area. Apart from these data to show that they are effective in
geological mapping, the performance showed by Landsat data suggests they can substitute
geophysical data which are relatively very expensive.
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Mshiu, E.E., 2011. Landsat remote sensing data as an alternative approach for geological mapping in Tanzania: A case study in the Rungwe volcanic province, South-Western Tanzania. Tanzania Journal of Science, 37(1).