1. n. [Shale Gas]

The process of a source rock becoming capable of generating oil or gas when exposed to appropriate pressures and temperatures. As a source rock begins to mature, it generates hydrocarbons. As an oil-prone source rock matures, the generation of heavy oils is succeeded by medium and light oils and condensates. Above a temperature of approximately 100 degC [212 degF], only dry gas is generated, and incipient metamorphism is imminent. The maturity of a source rock reflects the ambient pressure and temperature as well as the duration of conditions favorable for hydrocarbon generation. Understanding maturation is especially important in shale reservoirs because of the shales dual role as source rock and reservoir rock.