Organic geochemical characteristics of crude oils from the Masila Basin, eastern Yemen

Early Eocene equatorial vegetation and depositional environment: Biomarker and palynological evidences from a lignite-bearing sequence of Cambay Basin, western India

“…Subsequently due to a marine transgressive phase when the basin became more open to sea, the mangrove elements seem to have invaded the ecosystem and achieved local dominance. Moreover, the pristane to phytane ratio in the upper shale layer (0.6-0.8) indicates anoxic depositional environment (Peters et al, 2005) whereas 1.5-1.8 values for the lignite horizon depict the suboxic condition (Hakimi et al, 2011). Therefore, the decreasing trend of pristane to phytane ratio toward upper shale horizon suggests more anoxic depositional environment relative to lower lignites (Fig.…”

“…In contrast, dominance of low to medium molecular n-alkanes with maximizing at nC 18 is visible in the shale layer. Enrichment of nC 14 to nC 18 suggests the contribution of marine algae (Hakimi et al, 2011). Marine or lacustrine algae significantly produce nC 15, nC 17 and nC 19 (Peters et al, 2005).…”

Organic geochemical characteristics of the Lower Cretaceous Abu Gabra Formation in the Great Moga oilfield, Muglad Basin, Sudan: Implications for depositional environment and oil-generation potential

“…These values are more indicative of terrigenous and/or microbially reworked organic matter perhaps related to lacustrine environments (Peters et al, 2005). Moreover, Berner and Raiswell (1983), Moldowan et al (1985), Hakimi et al (2011), Mohialdeen et al (2013) demonstrated that the sulfur content of bulk samples can also be used to discriminate marine from freshwater environments. High sulfur content of kerogen is indicative of carbonate rocks deposited in a marine environment (Mohialdeen et al, 2013), while the low sulfur concentrations are typical for a fresh water lacustrine environment (e.g., Berner and Raiswell, 1983).…”

Geochemical characteristics of crude oils, their asphaltene and related organic matter source inputs from Fula oilfields in the Muglad Basin, Sudan

“…Compound separation was performed on a column similar to the GC column. Saturated hydrocarbon ratios and the relative abundance of steranes and triterpanes were calculated from integrated peak areas of the relevant ions chromatograms m/z 191 and m/z 217 (Philp, 1985;Peters et al, 2005;Hakimi, 2011). Aromatic hydrocarbon ratios were also calculated from integrated peak areas of the relevant ion chromatograms (van Aarssen et al, 1999).…”

“…Peters and Moldowan 1993;Hakimi et al, 2011 andMakeen et al, 2013). Moreover, a plot of Pr/n-C 17 versus Ph/n-C 18 ratios has been used by several authors to classify oils and oil-source rock correlation (e.g., Shanmugam, 1985;Oforka et al, 2012;Makeen et al, 2013;Hakimi and Abdullah, 2013).…”