6
• Concentrations of total REE in coal ash exceed 500
ppm in several coal fields: Metmore mine in the
Gallup Formation (807 ppm), Standing Rock (523
ppm), Barker Creek (528 ppm), Mt. Taylor (696
ppm), Star Lake (795 ppm), and Monero (1026
ppm) coal fields in the San Juan Basin and in the Van
Houten area of the Raton Basin (992 ppm).
• Some coal fields have elevated concentrations of Sc.
Figure 5. Total REE vs. ash content of coal samples from the
San Juan and Raton Basins. Note higher TREE are found in
samples with lower ash contents
Figure 7. TREE normalized to North American Shale
Composite (NASC). Legend of colors in Figure 5
Figure 6. TREE normalized to chondrite. Legend of colors in
Figure 5
Figure 8. Box and whisper plot of TREE by coal field (in
ppm). Legend of colors in Figure 5
Figure 9. Box and whisper plot of Sc (in ppm) by coal field.
Legend of colors in Figure 5