Stable isotope effects of selective preservation during early diagenesis

The delta super(13)C composition of decomposing organic matter was studied in an effort to better understand the major processes active during early diagenesis of organic matter. The degradation and loss of super(13)C-enriched labile organic components, primarily carbohydrates and proteins, leads to a significant decrease of delta super(13)C in the residual organic matter. In sapropelic organic matter of algal origin, the selective preservation of super(13)C-depleted paraffinic macromolecular components results in an overall relative decrease in delta super(13)C of up to 4 ppt.