| R1 [N = 4] | R2 [N = 10] | |
| Calcium * | Slightly calcareous *
(6.17 %) |
Non-calcareous *
(3.41 %) |
| Scandium | 22.5 ppm | 14.5 ppm |
| Chromium | 298.5 ppm | 124.0 ppm |
| Iron | 5.92 % | 4.56 % |
| Rubidium | 131.5 ppm | 159.1 ppm |
| Rare earths (overall) | Lower | Higher |
| Hafnium | 4.06 ppm | 5.51 ppm |
| Tantalum | 1.053 ppm | 0.919 ppm |
| Thorium | 10.79 ppm | 15.98 ppm |
|
*Clays with a calcium content < 3.6% (calcium carbonate [Ca2O] <5 %) may be considered non-calcareous (Tite et al.1982: 111). Calcareous clays have 10.7-17.9 % calcium (15-25 % calcium carbonate) (Tite 1999: 185, 216). [Calcium content in Ca2O calculated from atomic weights (Ca = 71.5%]. |