ABSTRACT
Experiments designed to simulate burial maturation have provided information on the geochemistry of classes of organic constituents in Holocene sediments of different origin. Humic acids and kerogens isolated from laboratory-heated Laguna Mormona, Baja California, algal mat (sapropelic facies) and Staten Island, California, peaty deltaic soil (humic facies) were characterized by a variety of techniques including elemental analysis, electron spin resonance, programmed temperature pyrolysis, vitrinite reflectance, and stable isotope ratios.
The study shows that the generation of kerogen during burial is the net result of temperature/time dependent synthetic and destructive reactions involving protokerogen and associated solvent-extractable organic matter. For the Staten Island sediment, where the initial content of humic substances is high, conversion of humic acid to gas-prone kerogen is quantitatively the most significant maturation process. For the Laguna Mormona algal mat, where lipid content is high, evidence suggests that some formation of oil-prone kerogen may occur by cross-linkage and binding of free lipids during diagenesis. Kerogen formation from humic acid in this sediment is minor.
