Lipids of an upper Albian limestone, Deep Sea Drilling Project Site 465, Section 465A-38-3 ( DSDP).

Abstract

The lipids of an Albian carbonaceous limestone show evidence of high algal productivity. They contain a preponderance of chlorophyll derivatives, algal markers, and marine sterol distributions. The low percentages of lipids derived from terrestrial plant waxes and resins suggest that no major vegetated continental landmasses were present nearby. This agrees with the plate-tectonic reconstructions for the Albian of the NW Pacific. The predominance of hopanoids over other polycyclic isoprenoids may indicate extensive bacterial activity at the time of sedimentation. The association between high productivity, good lipid preservation, and bacterial activity is rationalized here in terms of an oxygen-minimum zone, overlain by productive water masses. Diagenesis has progressed to the medium stage.-from Authors