Organic Geochemical Analysis of Oil Inclusions in Quartz Collected from Afghanistan and Pakistan

Abstract

This study conducted organic geochemical analyses of oil inclusions in quartz samples collected from Afghanistan and Pakistan. Samples from both countries contained large amounts of n -alkanes; however, sterane, triterpane, and isoprenoid hydrocarbons were not detected. Small amounts of iso - and anteis o -alkanes as well as alkylcyclohexanes were identified. The individual carbon isotope compositions of n -alkanes showed different trends between the two sample sets. The fluorescent compounds were separated into the polyaromatic hydrocarbon (PAH) fraction. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that alkylbenzenes, particularly ethylbenzene, were the major components in the PAH fraction. The fluorescence observed in the oil-bearing quartz was attributed to the presence of alkylbenzenes.