TABLE 2.
Chemical analysis of sediments from McMurdo Ice Shelf ponds
| Chemical | Concn (μg · [cm3 of sediment]−1)a
|
|||||
|---|---|---|---|---|---|---|
| Fresh | Orange | P-70 | Skua | Brack | Salt | |
| Na+ | 301 | 815 | 442 | 116 | 902 | 4,688 |
| CI− | 104 | 215 | 377 | 64 | 532 | 4,688 |
| SO42− | 416 | 365 | 279 | 75 | 2,088 | 7,922 |
| SRP | 0.24 | 1.46 | 0.61 | 0.09 | 0.24 | 0.31 |
| Kjeldahl nitrogen | 305 | 292 | 786 | 377 | 617 | 396 |
| NH4+ nitrogen | 97 | 22 | 85 | 21 | 12 | 12 |
| NO3− nitrogen | 0.62 | 1.72 | 0.15 | 0.08 | <0.09 | 0.03 |
| NO2− nitrogen | 0.05 | 0.73 | 0.05 | 0.03 | <0.01 | 0.02 |
| pH | 9.1 | 7.7 | 8.9 | 8.4 | 8.5 | 7.7 |
a
Values are for sediments taken from 0 to 5 cm below the cyanobacterial mat at a water depth of 10 to 20 cm. All sediments contain iron at >4.6% (dry weight).