Van Krevelen diagram

Van Krevelen diagrams are graphical plots developed by
Dirk Willem van Krevelen (chemist and professor of fuel technology at the TU Delft) and used to assess the origin and maturity of kerogen and petroleum. The diagram cross-plots the hydrogen:carbon atomic ratio as a function of the oxygen:carbon atomic ratio.
Types of kerogen.
Different types of kerogen have differing potentials to produce oil during maturation. These various types of kerogen can be distinguished on a van Krevelen diagram.