Origin of fossil raw materials and their composition

The origin of the fossil raw materials crude oil, coal and natural gas is rooted in photosynthesis, in which plants convert carbon dioxide and water into carbo- 

This composition indicates that a large proportion of petroleum-forming microorganisms belongs to the phytoplankton class the presence of chlorophyll corroborates this assumption. 

The presence of the various geochemical markers can be used in crude-oil exploration to assess the maturity of the oil. 

The hydrocarbons which are formed pass up through the parent rock into higher layers, until diffusion is blocked by impermeable strata and the crude-oil storing rock strata are formed. This crude-oil formation process explains why 

In contrast to crude-oil formation, modification of the hydrocarbon skeleton is not the most important reaction in the formation of coal. Coal is formed by conversion of land-based plants into peat, lignite, hard coal, anthracite and graphite. 

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