Application of Crosta technique for porphyry copper alteration mapping, using ETM+ data: A case study of Meiduk and SAR Cheshmeh areas, Kerman, Iran  Figure 2: The hydroxyl PC4 image shows the altered areas in bright pixels.  Figure 3: This image is obtained by using the eigenvector loadings of PC5 for enhancing iron oxide. The bright pixels are the areas with iron oxide.  Figure 4: This image is obtained by making RGB of hydroxyl image(red), iron oxide image(green) and average of these two images( blue).The highly altered areas are shown with bright pixels. |