Thermodynamic stability of various alkylated, dealkylated and rearranged 17α- and 17β-hopane isomers using molecular mechanics calculations

Kolaczkowska, Ewa; Slougui, Nacer-Eddine; Watt, David S.; Maruca, R.; Moldowan, J. M.

doi:10.1016/0146-6380(90)90140-u

Cited by 114 publications

(34 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The Ts/(Ts+Tm) ratio is both a maturity-and source-dependent parameter (Moldowan et al, 1986;Kolaczkowska et al, 1990). In this study, the ratios are around 0.96 for all maceral groups (Table 2b) and the 22S/(22S+22R) ratios show only slightly different values.…”

Section: Saturated Hydrocarbonsmentioning

confidence: 47%

Comparison of the Geochemical Characteristics of “Barkinite” and other Macerals from the Dahe Mine, South China

Sun

Horsfield

2005

Energy Exploration & Exploitation

View full text Add to dashboard Cite

Late Permian coal samples from the Dale Mine, South China, were separated into maceral groups in order to compare the characteristics of "barkinite" with vitrinite, inertinite, and sporinite. The maceral groups were extracted and analysed by GC-MS. The extract residues (kerogen) were analysed by open-system pyrolysis. The results indicate that "barkinite" has geochemical characteristics different from those of vitrinite, inertinite, and sporinite. The significant differences lie in the compound contents obtained by open-system pyrolysis method. The contents of saturated and aromatic compounds from the "barkinite" sample are also different from the vitrinite, inertinite, and sporinite samples, but these differences are observed only in their compound quantities.

show abstract

Section: Saturated Hydrocarbonsmentioning

confidence: 47%

Comparison of the Geochemical Characteristics of “Barkinite” and other Macerals from the Dahe Mine, South China

Sun

Horsfield

2005

Energy Exploration & Exploitation

View full text Add to dashboard Cite

show abstract

“…Table 4 shows that the isomerization ratios of C 31 -hopane (H 31 -22S/(22S+22R)) in Soxhlet extracts and hydropyrolysates are all about 0.6, very close to the end point. Tm (C 27 18α-trisnorhopane) is less stable than Ts (C 27 17α-trisnorhopane), and can be transformed to Ts with increasing maturity [43,46]. Ts/(Ts+Tm) ratio depends on both of source and maturity [47].…”

Section: Maturity-related Biomarker Parametersmentioning

confidence: 99%

The comparison of biomarkers released by hydropyrolysis and Soxhlet extraction from source rocks of different maturities

Liao

Fang

et al. 2012

Chin. Sci. Bull.

View full text Add to dashboard Cite

The Permian Dalong Formation (P 2 d) source rocks from the mature Guangyuan outcrop section and the overmature Wangcang outcrop section in Sichuan Basin were selected. The Soxhlet extraction and kerogen catalytic HyPy were conducted on the P 2 d source rocks. The biomarkers obtained by both methods were compared to discuss their difference and the influence extent of thermal maturation on covalently bound biomarkers. The results show that covalently bound biomarkers can hardly be correlated to the corresponding free biomarkers due to severe thermal alterations and/or interference of migrated hydrocarbons in both outcrop sections and thermal maturation have much lower influence on covalently bound biomarkers in kerogens than on free biomarkers in Soxhlet extracts. The application of HyPy in study of biomarker geochemistry can reduce the thermal maturation effect on biomarkers (R o ≤2.4%) to a greater extent and the interference of migrated hydrocarbons between interbedded layers. The covalently bound biomarkers released by HyPy are useful in the study of biomarker geochemistry and oil-source correlation on high-overmature source rocks.

show abstract

“…The αα-hopane is less thermodynamically stable than either 17β,21α(H)-moretane 103 or 17α,21β(H)-hopane, and it is largely undetected in petroleum and mature petroleum 104 source rocks (Bauer et al, 1983;Kolaczkowska et al, 1990). 105…”

mentioning

confidence: 99%

Diagenetic and detrital origin of moretane anomalies through the Permian–Triassic boundary

French

Tosca

Cao

et al. 2012

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Many biogeochemical anomalies coincide with the Late Permian Extinction 1 (LPE; 252.28 Ma). Several mechanisms have been proposed to explain the 2 moretane/hopane anomaly that has been identified in samples from Meishan GSSP 3 section in southeastern China. Here, we report homohopane, 2α-and 3β-4 methylhomohopane and lithological data for a drill core from the Meishan section in 5 southeastern China. Three intervals of elevated C 30 moretane/hopane ratios are recorded 6 in the Lungtan, Yinkeng and Helongshan Formations. Moretane/hopane ratios of C 31-34 7 homohopanes and the 2α-and 3β-methylhomohopanes display the same stratigraphic 8 patterns as the C 30 moretane/hopane record. In light of the multiple and parallel moretane 9 anomalies for the homohopane and 2α-and 3β-methylhomohopane series, enhanced input 10 from higher plant organic matter, such as coal and peat, does not adequately explain the 11 observed isomer patterns. Correlation of high moretane/hopane ratios with low C 35 HHI 12 and high hopane/sterane values suggest increased input of hopanoids from oxic soils. 13Additionally, moretane/hopane ratios show excellent correlations with total clay 14 percentages and specific clay types, particularly chlorite, illite, and mixed layer 15 illite/smectite. We conclude that a combination of episodic hopanoid input from soil 16 bacteria and diagenetic effects related to redox and detrital clays generated the unique 17 moretane/hopane patterns at Meishan.

show abstract

Thermodynamic stability of various alkylated, dealkylated and rearranged 17α- and 17β-hopane isomers using molecular mechanics calculations

Cited by 114 publications

References 22 publications

Comparison of the Geochemical Characteristics of “Barkinite” and other Macerals from the Dahe Mine, South China

Comparison of the Geochemical Characteristics of “Barkinite” and other Macerals from the Dahe Mine, South China

The comparison of biomarkers released by hydropyrolysis and Soxhlet extraction from source rocks of different maturities

Diagenetic and detrital origin of moretane anomalies through the Permian–Triassic boundary

Contact Info

Product

Resources

About