POTENTIAL FOR AMORPHOUS KEROGEN FORMATION VIA ADSORPTION OF ORGANIC MATERIAL AT MINERAL SURFACES

The traditional model for the formation of kerogen in sediments is tha t biopolymers undergo biochemical degradation, followed by polymerizat ion and condensation, resulting in an insoluble product. An alternativ e method of kerogen formation has been postulated, based on observatio ns that certain biopolymers may be highly resistant to microbial degra dation, indicating that these components can be selectively preserved. Clay minerals have strong adsorption and catalytic properties, with a high effective surface area, and are commonly abundant components of organic-rich sediments. Hence, clays are likely to adsorb organic matt er in sediments. Following mineral dissolution of a sediment, clay-ads orbed organic material may give rise to an insoluble polymer, which wo uld possess many of the characteristics of amorphous kerogen. Although the quantitative importance of clay adsorption as a vector of carbon preservation is currently unclear, in certain environments this proces s could account for the formation of amorphous kerogen.