Formation of Biogenic Depositions from Kerogen

The evolution of sedimentary organic matter (OM) under the influence of increasing burial depth and related temperature rise is termed maturation and this process is commonly subdivided into three stages, i.e., diagenesis, catagenesis, and metagenesis (Eigure 33). 

We can determine these stages as follows. Diagenesis is microbial and chemical transformations of sedimentary organic matter at low temperature and it has been started in recently deposited sediments. Catagenesis has involved the formation of 

Transformation of the initially deposited remains of living organisms started in the water columns and in the upper layers of bottom sediments of ancient seas. Random polymerization and condensation reactions of degraded biopolymers are believed to form the initial geopolymers, which contain humin, fulvic and humic acids. Until now these compounds (very typical for soil humus as well) are not well determined on the molecular level, but they are differentiated on the basis of their solubility in acids and bases. 

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