Table 2. Relative proportions and occurrences of isoprenoidal dialkyl glycerol diethers, ether-bond biphytanes, and isoprenoidal hydrocarbons at recent AOM sites.
| Major ANME cluster
|
Relative occurrence*
|
|||||||
|---|---|---|---|---|---|---|---|---|
| Sample | Ref(s). | (arch + OH-arch)/arch — 1 | Biphytanes | Crocetane | CrocetaneΔ | PMI | PMIΔ | |
| Eel River PC 36 (4-7 cm) | 28 | ANME-2 | 2.08 | NP | ++ | + | +++ | ++ |
| Santa Barbara SB-pc24 | 28, 30 | ANME-2 | 2.52 | NP | + | NP | - | ++ |
| Guaymas core C | 26 | ANME-2 | 1.07 | -† | NP | NP | NP | NP |
| Guaymas core T | 26 | ANME-2 | 0.78 | -† | NP | NP | NP | NP |
| Hydrate Ridge | 9, 29, 31 | ANME-2 | 1.00 | NP | +++ | + | +++ | ++ |
| Eel River ERB-Hpc4 | 25, 28, 30 | ANME-1 | 0.25 | NP | + | - | - | NP |
| Guaymas core A | 26 | ANME-1 | 0.05 | ++† | NP | NP | NP | NP |
| Napoli crust MN16BT2 | 27 | ANME-1 | 0.20 | +++ | + | NP | +++ | NP |
Predominating AOM cluster, ratios of archaeol vs. sn-2-hydroxyarchaeol, and occurrences of archaeal lipids of selected AOM sites are tabulated. Note that the lipid data derive from free lipid extracts (not from hydrolysis). NP, not published.
*
Relative occurrences of crocetane, unsaturated crocetenes (up to two double bonds), PMI, and unsaturated PMIs (up to five double bonds). Number of plus signs designates relative abundances. Minus sign denotes the absence of a compound.
†
Internally cyclized biphytanediols.