Table T15. Biomarker carbon number ranges and relative abundances in samples from Section 198-1207B-44R-1 and their putative biological source(s) and process of formation with references.

Biomarker class components (code)	Range	Relative abundance			Putative biological source(s)/process of formation	References
		Upper	Middle	Lower
n-Alkyl compounds:
Lower alkanes with OEP	C13-C19	+++	+++	+++	Algae, bacteria, cyanobacteria	Han et al., 1968; Gelpi et al., 1970; Brassell et al., 1978
Higher alkanes with OEP	C23-C33	ND	+	+	Vascular plants	Eglinton and Hamilton, 1963; Simoneit, 1978
Branched compounds:
Monomethylalkanes (MA)	C14-C21	ND	+	+++	Bacteria, cyanobacteria	Shiea et al., 1990; Dachs et al., 1998; Köster et al., 1999
Dimethylalkanes (DMA)	C17-C19	ND	ND	+++	Cyanobacteria	Shiea et al., 1990; Kenig et al., 1995; Köster et al., 1999
Branched alkenes (BA)	C18?	ND	ND	++	Cyanobacteria	Philp et al., 1978; Brassell et al., 1978
Acyclic and cyclic isoprenoids:
TMUD, TMDD, TMTD, TMPD	C14-C16, C18	+++	+++	+++	Photoautotrophs	Didyk et al., 1978; Volkman and Maxwell, 1986
Pristane (PR)	C19	++	+	+	Photoautotrophs	Didyk et al., 1978; Goossens et al., 1984
Phytane (PH)	C20	+++	++	++	Photoautotrophs, methanogens	Didyk et al., 1978; Brassell et al., 1981
C20 terpane	C20	+++	++	ND	Bacteria?	Aquino Neto et al., 1982; Ourisson et al., 1987
Steroids:
5(H)- and 5(H)-steranes	C27-C29	+++	+++	+++	Eukaryotes/sterol reduction	Mackenzie et al., 1982; Volkman, 1986
5(H)- and 5(H)-steranes	C30	+	+	ND	Marine eukaryotes/sterol reduction	Moldowan et al., 1990
4- and 5-sterenes	C27-C29	+++	+++	+++	Eukaryotes/sterol dehydration	Mackenzie et al., 1982; Peakman and Maxwell, 1988
4- and 5-sterenes	C30	+	+	ND	Marine eukaryotes/sterol dehydration	Moldowan et al., 1990; Peakman and Maxwell, 1988
4,22- and 5,22-steradienes	C29	ND	ND	+	Eukaryotes/sterol dehydration	Rullkötter et al., 1984; Farrimond et al., 1986
20S, 20R diasterenes	C27-C29	+	+	+	Eukaryotes/sterene rearrangment	Brassell et al., 1984; Peakman and Maxwell, 1988
A-ring monoaromatic	C27-C29	+	++	+	Eukaryotes/sterol aromatization	Hussler et al., 1981; Brassell et al., 1984
B-ring monoaromatic anthra-	C27-C29	+	++	+	Eukaryotes/sterol aromatization	Hussler and Albrecht, 1983; Rullkötter and Welte, 1983
A-nor, B-ring aromatic anthra-	C22	NA	+	NA	Eukaryotes/sterol aromatization	Peakman et al., 1986
Triterpenoids:
17(H),21(H)-hopanes	C27, C29-C31	+++	+++	+++	Prokaryotes	Ourisson et al., 1979, 1987; Rohmer et al., 1992
17(H),21(H)-hopanes	C27, C29-C31	++	++	++	Prokaryotes	Ourisson et al., 1979, 1987; Rohmer et al., 1992
17(H),21(H)-methylhopanes	C34	++	+	ND	Cyanobacteria, methylotrophs	Ourisson et al., 1987; Summons and Jahnke, 1990
Hopanes C32	C32, C33	+++	+	+	Bacteria, methylotrophs	Ourisson et al., 1979, 1987; Rohmer et al., 1992
Hop-17(21)-enes	C27, C29-C31	+++	++	++	Bacteria, anaerobic phototrophs	Brassell and Eglinton, 1983; Rohmer et al., 1984
Aromatic hopanoids	C24, C27	NA	++	NA	Bacteria/aromatization	Greiner et al., 1976, 1977
Neohop-13(18)-enes	C27, C29, C30	++	+++	++	Bacteria, anaerobic phototrophs	Brassell and Eglinton, 1983; Howard et al., 1984
Fernenes	C30	+	++	+++	Bacteria, anaerobic phototrophs	Brassell and Eglinton, 1983; Howard et al., 1984
Dammarenes	C30	++	ND	ND	Bacteria?	Meunier-Christmann et al., 1991
Triterpene (dammaradiene?)	C30	ND	++	+++	Bacteria?	Brassell, 1984; Rullkötter et al., 1984
Triterpene (nordammaradiene?)	C29	++	++	+++	Bacteria?
Ketones:
Alkan-2-ones	C13-C25	NA	+	NA	Algae, bacteria/oxidation	Brassell et al., 1980
TMTD-2-one	C18	NA	++	NA	Photoautotrophs; oxidation	Simoneit, 1973
5(H)- and 5(H)-stanones	C27-C29	NA	++	NA	eukaryotes/sterol oxidation	Gagosian and Smith, 1979; Robinson et al., 1984
4-stenones	C27-C29	NA	++	NA	Eukaryotes/sterol oxidation	Edmunds et al., 1980; Brassell et al., 1987
Hopanones	C27, C29-C31	NA	++	NA	Bacteria, algae/predation, oxidation	Dastillung et al., 1980
Other biomarkers:
5-methyl-2-undecylthiophene	C20	NA	+	NA	Sulfurization	Sinninghe-Damsté et al., 1988, 1989
Phytenyl thiophenes (PT)	C20	++	++	++	Photoautotrophs; sulfurization	Rullkötter et al., 1984; Brassell et al., 1986
-, -, -, -tocopherols	C27-C29	NA	+++	NA	Photoautotrophs	Brassell et al., 1983; Goossens et al., 1984

Notes: Upper, middle, and lower refer to samples at 60-61 cm, 76-77 cm, and 103-104 cm of Section 198-1207B-44R-1, respectively. OEP = odd/even preference. +, ++, +++ = approximate relative abundances corresponding to major, minor, and trace amounts. ND = not detected. NA = not analyzed. See Table T16 for definitions of biomarker class components (codes).