Discrimination of igneous rocks using digital thematic Mapper data in Southern Sinai, Egypt
Title:
Discrimination of igneous rocks using digital thematic Mapper data in Southern Sinai, Egypt
Author:
Rakaiby, Maged L. El
Appeared in:
Geocarto international
Paging:
Volume 11 (1996) nr. 4 pages 61-69
Year:
1996-12
Contents:
Qualitative and quantitative studies of thematic mapper (TM) digital data have been applied in discrimination and classification of the exposed igneous rocks in southern Sinai, Egypt. The main aim of this study is to evaluate the lithological utility of the spectral information recorded in the visible and reflected infrared bands of Landsat TM data Iron oxide and albedo are the main features affecting the reflectance content characteristics of rocks. The typical overall appearance of igneous rocks is high reflectance at band 5 with sharp decreasing in reflectivity toward both shorter and longer wavelengths. Analysis of spectral curves of the exposed igneous rock units provided that the best spectral information about rocks rich quartz and feldspars is in band 5, iron-rich minerals are in bands 2 and 4, and the altered rocks is in band 7. Moreover, the rock units were more separable in bands 2, 4, 5, and 7, and each rock unit is best identified using band combinations from 4,5, and 7 bands.