Bacterial reworking and the abundance of organo-sulfur compounds in cretaceous kerogens from Sergipe Basin, Brazil
- Indiana Univ., Bloomington, IN (United States)
- Univ. of Bristol (United Kingdom); and others
Immature kerogens of Upper Cretaceous marine strata from Sergipe Basin, Brazil are composed of variable amounts of reddish-fluorescing amorphous organic matter (rAOM) and algal remains (alginite). Pyrolysates of the alginite-dominated kerogens have prominent n-alk-1-ene/n-alkane pairs, and {alpha},{omega} alkadienes. Concentration of organo-sulfur compounds (OSC) are low but dominate the non-aliphatic components. In contrast, pyrolysates of the rAOM-dominated kerogens have high concentrations of OSC (mainly C{sub 1}C{sub 5} alkylthiophenes) and alkyl-benzenes in addition to abundant n-alk-1-ene/n-alkane pairs. Microprobe analysis of individual macerals revealed that S/C ratios of the alginites; are 50 to 30% lower than S/C ratios of the rAOM, indicating preferential concentration of OSC in the latter. Low preservation of algal remains and presence of relatively pronounced hopenes/hopanes and isoprenoids in pyrolysates of rAOM-dominated kerogens indicate substantial bacterial processing of primary organic matter. Therefore, it is suggested that the rAOM-dominated kerogens are enriched in OSC due to increased bacterial reworking and efficient sulfur incorporation into rAOM.
- OSTI ID:
- 370456
- Report Number(s):
- CONF-960376-; TRN: 96:003805-0508
- Resource Relation:
- Conference: Spring national meeting of the American Chemical Society (ACS), New Orleans, LA (United States), 24-28 Mar 1996; Other Information: PBD: 1996; Related Information: Is Part Of 211th ACS national meeting; PB: 2284 p.
- Country of Publication:
- United States
- Language:
- English
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