Table 2.

Sample-based and buffered pixel-based validation results for phyllic and propylitic alteration zones. Coverage accuracy is computed from the overlap between labeled geochemical samples and the alteration map, while confusion matrices, overall accuracy, and 95% CI are derived from buffered pixel masks around the same samples.

Alteration Zone	Total Geochemical Points	Points Inside Alteration Map	Coverage Accuracy (%)	Buffered Confusion (TP / FN / FP / TN, pixels)	Overall Accuracy (%)	95% CI
Phyllic	114	108	94.74	898 / 213 / 427 / 10,033	94.5	94.1–94.9
Propylitic	47	45	95.74	299 / 491 / 1026 / 9755	86.9	86.3–87.5