Table 2. Approximate mean atomic composition in wt% from SEM-EDS and XRF.
‘–’ denotes undetected. The + and − values show the extremes.
| MR81A2249 | MR81A1436 | MR82A6000 | |||||
|---|---|---|---|---|---|---|---|
| C | 24 | +7 −4 | 22 | +2 −2 | 4.35 | +0.15 −0.15 | |
| N | 13 | +1.5 −3.5 | Trace | 4.2 | +0.4 −0.4 | ||
| O | 20 | +4.5 −5.4 | 13 | +2 −2 | 8.4 | +1.4 −1.4 | |
| Na | Trace† | Trace | – | ||||
| Mg | 0.4 | +0.07 −0.16 | – | – | |||
| Al | 0.5 | +0.2 −0.2 | 0.7 | +0.4 −0.3 | – | ||
| Si | 0.7 | +0.3 −0.4 | 2 | +1.6 −1.1 | 0.28 | +0.09 −0.09 | |
| P | Trace | – | – | ||||
| S | 2.1 | +0.6 −0.4 | 0.46 | +0.1 −0.1 | 1.34 | +0.16 −0.16 | |
| Cl | 1.4† | +1.7 −1.1 | 0.25 | +0.04 −0.03 | – | ||
| K | 0.2 | +0.05 −0.06 | 0.14 | +0.02 −0.03 | – | ||
| Ca | 0.8 | +0.19 −0.24 | 0.4 | +0.11 −0.13 | 0.24 | +0.08 −0.08 | |
| Fe | 1.2 | +0.74 −0.78 | 0.7 | +0.04 −0.2 | 1.12 | +0.41 −0.41 | |
| Ni | Trace | Trace | – | ||||
| Cu | 22 | +11 −14 | 45 | +4 −5 | 66.6 | +0.6 −0.6 | |
| Zn | 13 | +9 −7.5 | 16 | +1 −2 | 12.3 | +1.7 −1.7 | |
| As | Trace | Trace‡ | – | ||||
| Se | Trace | Trace‡ | – | ||||
| Sn | – | – | 1.1 | +0.01 −0.01 | |||
| Pb | Trace | Trace‡ | – | ||||
†
Cl and Na correlated in one position.
‡
Levels on the conserved link are <0.1× those on the corroded link.