The saturated and aromatic hydrocarbons from a significant number of oils and source rocks derived from terrestrial and marine organic matter have been analysed by GC and GC-MS. Results show that certain classes of biomarkers including bicyclic sesquiterpanes, tricyclic terpanes, pregnanes, methylsteranes, rearranged steranes, hopane sulfides, benzohopanes, long-chain alkylbenzenes and pentacyclic triterpanes can be used to distinguish differences in source input and/or depositional environments. Variations in the distributions of the naphthalenes, phenanthrenes, fluorenes, dibenzofurans, dibenzothiophenes, naphthobenzothiophenes and triaromatic steroid hydrocarbons may also reflect disparities in source input or sedimentary environments.