biomarkers as environmental indicators
C21 to C25 regular isoprenoids enriched in 13C relative to biomarkers of phytoplanktonic origin, high gammaceraneGrice et al., 1998b Sinninghe Damste et al., 1995 1
depositional environment typical biomarker patterns reference example
marine 24-n-propylcholestane Moldowan et al., 1985
lacustrine botryococcane and other biomarkers of Botryococcus (fresh to brackish water) elevated concentrations of C30 tetracyclic polyprenoids (fresh to brackish water) Metzger and Largeau, 1999 Holba et al., 2003
terrestrial organic matter input diverse biomarkers of higher plants Summons and Brocks, Treatise on Geochemistry
strongly anoxic conditions (water column anoxia?) 28,30-dinorhopane, 25,28,30-trisnorhopane, gammacerane1 Peters and Moldowan, 1993 Sinninghe Damste et al., 1995
photic zone euxinia2 isorenieratane, 2,3,6- and 2,3,4- trimethylarylisoprenoids, chlorobactane, Me, isobutyl maleimide Grice et al., 1996a, Hartgers et al., 1993, Koopmans et al., 1996a, Summons and Powell, 1987
carbonates and evaporites low diasterane/sterane ratios1 van Kaam-Peters et al., 1998
high 2a-methylhopane concentrations1 Summons et al., 1999
high 30-norhopanes1 Subroto et al., 1991

1 typical for, but not necessarily restricted to, this depositional environment

2 this might include environments with an anoxic and sulfidic water column that persists into the photic zone, or microbial mats in very shallow water settings that become anoxic within millimeters below the sediment water interface

chart adapted from Treatise on Geochemistry Review, Chapter 8, Summons and Brocks

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