Fig. 3: Downcore archaeal lipid biomarker distribution for core GeoB24917-1 (Pacman mud volcano).
From: Biomarker evidence of a serpentinite chemosynthetic biosphere at the Mariana forearc
Relative abundances of various archaeal core (C-) lipids (a) and archaeal IPLs (b) detected in pelagic sediments and serpentinite mud. We observe a shift from dominantly marine water column and marine detrital lipid biomarkers in pelagic sediments to a mixed methanotrophic and methanogenic signal in serpentinite mud. GDDs transition from a mixed (GDD-1, −2, -crenarchaeol) to an acyclic form (GDD-0) further suggesting a preferential production of acyclic GDGTs in the serpentinite mud. c Absolute concentrations of archaeal core lipids (dashed grey line; grey bullets) and IPLs (solid black line; filled black triangles) showing increase in archaeal IPL concentrations within less oxidized, i.e., dark blue, serpentinite mud. d Ratio of diether lipids (AR + OH-AR) to diether lipids + tetraether lipids (GDGTs) for core (dashed grey line; grey bullets) and intact polar lipids (solid black line; filled black triangles) suggesting an increase in abundance of core diether lipids in the less oxidized serpentinite mud. AR archaeol, cmbsf cm below seafloor, Cren crenarchaeol, GDD glycerol dialkyl diether, GDGT glycerol dialkyl glycerol tetraether, IPL intact polar lipid, OH-AR hydroxyarchaeol.
