Kinetics of Hydrocarbon Formation in the Sedimentary Cover of a Subducting Plate

The kinetics of hydrocarbon formation in the sedimentary cover of a subducting plate was numerically simulated using published estimates for the temperature of the subducting plate surface, subsidence rate, and the kinetic spectrum of aquatic organic matter. It was shown that the peak oil window occurs in a subduction environment at depths of 12.6–23.3 km and temperatures of 147.6–179.4°C and requires 0.1–6.4 million years. The scatter in the estimates of depth, temperature, and time required to reach the peak oil window is related to variations in subduction angle and velocity and temperature gradient in the published models. The estimates of depths and temperatures for the formation of hydrocarbons in the sedimentary cover of a subducting plate are higher than those for Cenozoic, Mesozoic, and Paleozoic sedimentary basins, whereas the time required for oil formation is shorter. It can be suggested that accumulations of liquid hydrocarbons could hardly be produced by the organic matter of the sedimentary cover of a subduction plate, but there are prospects for the formation of dry gas fields.