Table 1.
Concentration of natural radioactive elements (g/t) and thorium–uranium ratio in granites.
| Crystalline Granite Bedrock | Zone of Granite Disintegration | Granitic Sub-Soil | Clay | Soil | ||
|---|---|---|---|---|---|---|
| Belokurikha, Altai |
U | 6.4 ± 0.5 | 9.7 ± 0.9 | 8.0 ± 0.8 | 11.4 ± 1.8 | 8.6 ± 0.9 |
| Th | 21.1 ± 3.8 | 36.5 ± 3.5 | 52.6 ± 4.4 | 58.8 ± 4.8 | 35.9 ± 3.8 | |
| Th/U | 3.3 | 4.4 | 6.5 | 5.1 | 4.2 | |
| Kolyvan, Novosibirsk |
U | 9.6 ± 0.8 | 15.6 ± 1.3 | 10.2 ± 1.0 | 10.6 ± 1.1 | 4.9 ± 0.3 |
| Th | 34.0 ± 2.9 | 73.0 ± 5.9 | 47.1 ± 3.3 | 57.2 ± 4.6 | 14.9 ± 1.3 | |
| Th/U | 3.5 | 4.7 | 4.6 | 5.4 | 3.1 | |
| Zhuhai, Guangdong |
U | 26.1 ± 3.1 | 12.4 ± 0.9 | 8.0 ± 0.3 | 8.5 ± 0.3 | 8.1 ± 0.7 |
| Th | 100 ± 9.5 | 50.4 ± 3.1 | 51.2 ± 4.6 | 53.4 ± 4.6 | 47.6 ± 2.7 | |
| Th/U | 3.8 | 4.1 | 6.4 | 6.2 | 5.9 | |
| Echassières, Auvergne |
U | 18 [68] | n.d. | n.d. | n.d. | 6.5 ± 0.5 |
| Th | 1.7 [68] | n.d. | n.d. | n.d. | 4.6 ± 0.3 | |
| Th/U | 0.1 | n.d. | n.d. | n.d. | 0.7 | |
| Worldwide averages [69,70] |
U | 3.9 | n.d. | n.d. | 4.3 | 1 |
| Th | 18 | n.d. | n.d. | 14 | 5 | |
| Th/U | 4.6 | n.d. | n.d. | 3.2 | 5 |
n.d.—no data.