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LANDSAT-7 INTERPRETATION OF LINEAMENTS OVER THE SOUTHWESTERN PART OF ADAMAWA STATE, NORTHEASTERN NIGERIA Adewumi Adeniyi Johnpaul Department of Geological Sciences, Achievers University, Owo, Ondo State, Nigeria. Accepted October 09, 2013 This research work was carried out to map and interpret lineaments of the southwestern part of Adamawa state, northeastern Nigeria using LANDSAT-7. The image acquired was processed using the Principal Component Analysis (PCA) method in the ENVI 4.3 software. False colour composite was generated by combining bands using the same software. The image was imported into ILWIS 3.7 where it was georeferenced using latlon WGS84 with tiepoints. Lineaments length density and lineament intersection density was calculated for the area. Basic statistical analysis was also carried out on the data generated from lineaments of the study area. Results shows that the length of lineament in the area ranges from 0.6821km to 17.6668km with a total area of 298.1344km2 covered by the lineaments. Lineament azimuth ranges from between 4.107 and 180 in the study area. The study further shows that the largest amount of lineaments (60) are found on the alluvium and accounts for 26.55% of the total number of lineaments in the area. The lineaments distribution decreases on rock units in the following order: alluvium>Migmatite>shale and siltstone>porphyritic granite>sandstone, shale and clay>undifferentiated Basement Complex>shales, limestone and sandstone. Structural analysis from rose diagram show that the lineament orientation trends ENE-SWS which confirms that the lineaments with frequency between 51-60o has the highest distribution in the study area. Results shows that the lineament density of the area is 29.01km. Statistical analysis of lineament data reveals that the mean azimuth of lineaments is 84.61o with median and mode being 77.42o and 90o respectively. Histogram plot of the azimuth data from the area shows that the lineaments of the area has five modal classes of 40-60o, 60-80o, 80-100o, 120-140o and 160-180o which accounts for 23.90%, 26.11%, 19.03%, 10.18% and 4.87% of the total number of lineaments in the area respectively. Key words: Lineaments, Structural Analysis, Statistical Analysis, LANDSAT-7. Full Text PDF (1.06MB) |
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