GEOCHEMICAL CHARACTERISTICS OF CRUDE OILS FROM THE SHARARA‐C OIL FIELD, MURZUQ BASIN, SOUTHWESTERN LIBYA

Crude oil samples from the Sharara‐C oil field (Concession NC‐115, Murzuq Basin, SW Libya) were analysed by organic geochemical methods in order to infer the geochemical characteristics of their respective source rocks. Aromatic hydrocarbons were analysed by gas chromatography – mass spectrometry (GC‐MS), and gas chromatography – tandem mass spectrometry (GC‐MS‐MS) was used to analyse saturated biomarkers. The Sharara‐C oils are interpreted to have been generated by marine shales containing mixed terrigenous and marine organic materials deposited in an intermediate (suboxic) environment. Age‐specific biomarker ratios indicated that the oils are older than Cretaceous, and maturation‐related parameters pointed to their high thermal maturity. Consistent with previous studies, source rocks are inferred to be “hot” shales in the Lower Silurian Tanezzuft Formation.