Table 1.
Bulk geochemical composition of the sinter samples from the three mounds at El Tatio.
| Liquid | Steam | Dry | |
|---|---|---|---|
| TOC (% dw) | 0.10 | 0.10 | 0.07 |
| TN (% dw) | 0.02 | 0.04 | 0.01 |
| δ13C OC (‰) | -15.9 | -24.0 | -15.7 |
| δ15N TN (‰) | -0.9 | 5.4 | -1.1 |
| C/N | 5 | 3 | 7 |
| n-alkanes | 0.05 | 0.08 | 0.05 |
| Branched alkanesa | 0.11 | 0.14 | 0.04 |
| Octadecene (C18:1) | n.d. | 0.04 | n.d. |
| Hentriacontatriene (C31:3) | n.d. | 0.01 | n.d. |
| n-carboxylic acids | 2.53 | 2.71 | 2.35 |
| Unsaturated carboxylic acidsb | 0.39 | 0.34 | 0.23 |
| Dicarboxylic acidsc | 0.06 | 0.05 | 0.03 |
| Iso-/anteiso carboxylic acidsd | 0.71 | 0.38 | 0.24 |
| Other branched carboxylic acidse | 0.11 | 0.02 | 0.01 |
| Cyclopropyl acidsf | n.d. | n.d. | 0.03 |
| n-alkanols | 1.40 | 1.12 | 1.81 |
| Stigmastanol | 0.12 | 0.13 | 0.06 |
| β-sitosterol | 0.01 | 0.04 | n.d. |
| Cholesterol | n.d. | 0.01 | 0.17 |
| Pristane | 0.05 | 0.12 | n.d. |
| Phytane | 0.21 | 0.35 | n.d. |
| Squalane | n.d. | n.d. | 0.003 |
| Crocetane | n.d. | n.d. | 0.002 |
Concentration (μg g-1) and compositional distribution of lipid biomarkers. aSum of mono-methyl, di-methyl and tri-methyl alkanes. bSum of mono- and di-unsaturated carboxylic acids between 16 and 19 carbon units. cSum of dicarboxylic acids between 6 and 10 carbon units. dSum of iso and anteiso carboxylic acids between 15 and 19 carbon units. eSum of other mono-methyl (MM) carboxylic acids. fSum of cyclopropyl C17 and C19 acids. Please go to Supplementary Figures S5–S8 for consulting individual concentrations of the (normal, branched, and other) carboxylic acids, alkanols, and alkanes families.