Maturity of ancient sedimentary organic matter

The light hydrocarbons of the gasoline range (C4—C10) account for t.30% of a crude oil, and so any information that can be gained from these components is likely to be reasonably representative of the bulk oil. The Cy 

9 I Rock-Eval and related pyrolytic assessment of maturity 

For an oil, the maximum temperature can generally be assumed to equate to the temperature of generation/ expulsion of the hydrocarbons. 

The mode of formation of light hydrocarbons clearly has implications for their application as maturity indicators, and Mangos model is not universally accepted (ten Haven 1996). The distribution of light hydrocarbons is significantly affected by variations in the original contributions to kerogen (Hayes 1991 Odden et al. 1998), so maturity differences inferred from light hydrocarbon distributions must be treated with caution. 

The carbon preference index (CPI) is a numerical means of representing the odd-over-even predominance in -alkanes in a particular carbon-number range. It is often used as a maturity measurement where 

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