No abstract

Ronald Hill specializes in petroleum geochemistry and has more than 12 years of professional experience, which includes his years in Exxon-Mobil and Chevron. Currently, he is a research geologist for the U.S. Geological Survey. His interests include the investigation of shale-gas resources and the processes that control petroleum generation. He holds geology degrees from the Michigan State University (B.S. degree),

No abstract

No abstract

Summary In this study the saturated and aromatic hydrocarbon fractions of a marl sample from a Messinian (late Micoene) evaporitic basin located in the northern Apennines, and four oils, Rozel Point oil (Utah, USA; Miocene) and three seep oils from Sicily (Messinian), have been studied by GC with simultaneous FID and FPD detection and by GC-MS. All samples show characteristics which might be linked to hypersaline conditions prevailing during the time of deposition. Some of these characteristics are: a very low pristane/phytane ratio (<0.1), a relatively high abundance of docosane (C 22 ) and gammacerane and a series of extended hopanes and/or hop-17(21)-enes maximizing at C 35 . The aromatic hydrocarbon fraction of all samples is dominated by organic sulphur compounds of which 2,3-dimethyl-5-(2,6,10-trimethylundecyl) thiophene is the most abundant compound. The suggestion of Meissner et al. (1984), that the source rock of Rozel Point oil was deposited under hypersaline conditions in a playa-like system, is supported by the organic geochemical characteristics of this oil.