1. n. [Shale Gas]
The last stage of maturation and conversion of organic matter to hydrocarbons. Metagenesis occurs at temperatures of 150 to 200 degC [302 to 392 degF]. At the end of metagenesis, methane, or dry gas, is evolved along with nonhydrocarbon gases such as CO2, N2, and H2S, as oil molecules are cracked into smaller gas molecules.
