Total Organic Carbon

The content of organic carbon can optionally be modeled based on the principle of preservation in the microbial diagenesis zone. The amount of organic matter in rocks is affected by three principal factors: primary photosynthetic productivity, effectiveness of preservation, and dilution by inorganic material. Of these, preservation is generally the most important. Rapid accumulation of sediments shortens the residence time of organic matter in the hostile oxic zone and thus promotes preservation. An empirical relation between total organic carbon, sedimentation rates, and shale and clay content, based on data published by Waples (1984), has been implemented in the simulation model. The model also has provision for user-defined values and a combination of either method by giving a set of scaling factors for multiplication of the TOC values derived from burial-dependent preservation.

The characterization of kerogen can be tied to the paleo environment. The kerogen composition is assumed to be liptinic for a marine paleo environment and humic for a terrestrial paleo environment.

The characterization of organic matter in anthropogenic times includes lipid, protein, and carbohydrates as key components. Therefore a mixture of these 3 components are used to define a typical algal (76%, 14% & 10%), liptinic (53%, 4%, & 43%), and humic (35%, 0%, & 65%) kerogen. The proposed mixtures result in expected H/C and O/C values in the van Krevelen diagram.

Alternatively the composition is defined by the user.