Table I.
Isotopic composition of the applied tracer solution and of unlabeled solution
The abundances were calculated from three SIMS measurements of air-dried drops of solution on silicon substrate (Eq. 2) and presented as mean percentages ± 2σ (n = 3). The reference literature data are taken from Böhlke et al. (2005). Two different batches of potassium tracer were used in the four types of experiments, as listed in Table II.
| Isotopes | 24Mg | 25Mg | 26Mg |
|---|---|---|---|
| Magnesium isotopes | |||
| Tracer | 2.0 ± 0.2 | 1.0 ± 0.2 | 97.0 ± 0.2 |
| Unlabeled | 79.1 ± 2.4 | 9.6 ± 1.4 | 12.8 ± 2.4 |
| Literature | 79.0 | 10.0 | 11.0 |
|
39K |
41K |
||
| Potassium isotopes | |||
| Tracer experiment 1 | 2.9 ± 0.6 | 97.1 ± 0.6 | |
| Tracer experiments 2, 3, 4 | 5.5 ± 0.6 | 94.5 ± 0.6 | |
| Unlabeled | 93.7 ± 1.0 | 6.3 ± 1.0 | |
| Literature | 93.3 | 6.7 | |
|
40Ca |
44Ca |
||
| Calcium isotopes | |||
| Tracer | 3.2 ± 2.6 | 96.7 ± 2.6 | |
| Unlabeled | 97.8 ± 0.2 | 2.2 ± 0.2 | |
| Literature | 96.9 | 2.1 | |