Migration of Organic Molecules from Sediment to Fossils - Biopolymers: A Molecular Paleontology Approach - page 82

a

Fossil dicot leaf

I

Pr1

m/z 130+131

G2 G3

G1 G5

?

P1

I

B3 G4

B2

N

Pr2

Ps2 P2

2 0

B4

Ps1 23

25

28

G5

m/z 154+168+180+182+194+196

S1
S2

Pr1

S3

b

Fossil conifer

B2

Pr1

?

Ps? Ps2
P1

B4

I

P2 G5

G4

G1

B3 G2

Pr2

G3

Ps1

N

17

23

29

20

33

Retention time

Fig. 4.4 ( a ) Partial py-GC-MS total ion current chromatogram of fossil dicotyledon leaf indicat-
ing the presence of moieties related to benzene derivatives, polysaccharides, phenols, lignin and
protein together with n-alkane/n- alk-1-ene homologues, number indicating the carbon chain
length. m/z 130 + 131 reveals the presence of methyl indole. m/z 154 + 168 + 180 + 182 + 194 + 196
reveals the distribution of syringyl moieties. ( b ) Partial py-GC-MS total ion current chromatogram
of fossil conifer, showing released moieties related to benzene derivatives, polysaccharides, phe-
nols, lignin and protein, together with n-alkane/n-alk-1-ene homologues. B2 : dimethylbenzene,
B3 : trimethylbenzene, B4 : tetramethylbenzene, N : naphthalene. Guaiacyl related units. G1 :
2-methoxyphenol, G2 : 4-methyl-2-methoxyphenol, G3 : 4-ethyl-2-methoxyphenol, G4 : 4-ethenyl-
2-methoxyphenol, G5 : 3-allyl-6-methoxyphenol. Syringyl related units. S1 : 4-ethyl-2,6-
dimethoxyphenol, S2 : 2,6-dimethoxy-4-vinylphenol, S3 : 4-ally-2,6-dimethoxyphenol. Pr1 :
Prist-1-ene. P1 : methylphenol, P2 : dimethylphenol. Polysaccharide pyrolysis products: Ps1 :
2-methyl-2-cyclopenten-2-one, Ps2 : 2,3-dimethyl cyclopenten-1-one, Ps?? : unknown moiety

TMAH assisted pyrolysis was conducted on the fossil conifer to characterise
further the fossil composition and determine the lipid distribution. The thermochemol-
ysis trace (Fig. 4.5 ) reveals methylated equivalents of the lignin moieties, aromatics
(see Hatcher and Clifford 1994 ; Hatcher et al. 1995 ; Clifford et al. 1995 ; Almendros