Figure 9
Spatial distribution of coated bedrock exposures (red) in the Rouyn-Noranda study area (Fig. 2), as generated by a maximum likelihood classifier without a null class (overlain on reflectance data derived from OLI Band 5, acquired in the near infrared); compare with Fig. 8. Though this database expands the successful detection of coated bedrock in the study area relative to that of the database given in Fig. 8, it is also characterized by numerous examples of false positives, rendering the database much less useful. Some of the most notable examples of false positives are labeled with numbered yellow circles: (1) geological materials exposed within the Horne smelter site; (2 and 3) geological deposits in tailings ponds; (4) areas of exposed uncoated rock and organic materials in wetlands; (5 and 6) uncoated rock exposed or very shallowly submerged along lake shorelines. Image at right is an enlargement of the area outlined in yellow at left. Image classification and processing were performed using Geomatica software78.
