[Retracted] Use of Geochemical Fossils as Indicators of Thermal Maturation: An Example from the Anambra Basin, Southeastern Nigeria

Table 3

Gas chromatographic data showing values of n-alkanes ratio and their CPI.

Sample ID	Pr/Ph	Pr/nC17	Ph/nC18	CPI	OEP-1	OEP-2
EN 1331 (V2)	5.88	0.8	0.57	1.57	0.4	0.57
EN 1331 (V5)	7.26	1.98	0.33	1.83	0.43	0.56
EN 1331 (V6)	8.97	3.91	0.46	1.53	0.4	0.57
EN 1325 (P1)	5.5	1.62	0.4	1.69	0.56	0.57
EN 1325 (P3)	5.08	1.1	0.2	1.75	0.43	0.61

Notes: CPI = carbon preference index = 2(C₂₃ + C₂₅ + C₂₇ + C₂₉)/(C₂₂ + 2(C₂₄ + C₂₆ + C₂₈) + C₃₀). OEP-1 = (C₂₁ + C₂₃ + C₂₅)/(4C₂₂ + 4C₂₄). OEP-2 = (C₂₅ + C₂₇ + C₂₉)/(4C₂₆ + 4C₂₈). OEP = odd-even predominance.