Estimates for bitumen and oil range slightly lower, with oil-hydrogen being least affected by water-derived hydrogen. 45 and 79% of carbon-bound hydrogen in kerogen is derived from water. Isotopic mass-balance calculations show that, depending on temperature (310-381?C), time (12-144 h), and source rock type, between ca. Converging isotopic trends of inorganic (water) and organic ( kerogen, bitumen, oil) hydrogen with increasing time and temperature document that water-derived hydrogen is added to or exchanged with organic hydrogen, or both, during chemical reactions that take place during thermal maturation. Immature source rock chips containing different types of kerogen (I, II, IIS, III) were artificially matured in isotopically distinct waters by hydrous pyrolysis and by pyrolysis in supercritical water. The results support a bacterially-mediated, degradative origin for Type II-S amorphous organic matter, with algal remains as the primary source of the kerogen.ĭ/H isotope ratios of kerogen, bitumen, oil, and water in hydrous pyrolysis of source rocks containing kerogen types I, II, IIS, and III
There was a marked enrichment of thiophenic sulfur in the light-colored AOM of both samples (and also pyrrolic nitrogen in the case of the Monterey) relative to the alginite. kerogen had a relatively high concentration of alkylbenzenes and alkylthiophenes, while its elginite concentrate showed a more aliphatic character upon pyrolysis.
The pyrolyzate of the dominant light brown-fluorescing AOM of the Duwi Fm.
#DUSTBORN 20S 30S SERIES#
In contrast, the pyrolyzates of its alginite concentrate showed a highly aliphatic character, typical of this maceral, with the series of n-alkenes and n-alkanes (C6- C26) predominating. kerogen sample was comprised chiefly of light red-fluorescing amorphous organic matter (AOM), the flash pyrolyzate of which was characterized by a predominance of alkylbenzenes, alkylthiophenes and alkylpyrroles. U.S.A.) and Duwi Formation (Campanian/Maastrichtian, Egypt) were separated by density gradient centrifugation. Maceral fractions of the Type II-S kerogens from the Monterey Formation (Miocene. Geochemistry of the alginite and amorphous organic matter from type II-S kerogens
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