Composition index of n-alkanes and paleoenvironmental study in sediments of the Arctic

This paper reports different concentration patterns of n-alkanes distribution in the sediments from the Chukchi Sea, the Bering Sea in the Arctic. Factor statistical analysis method is used for studying the source of n-alkanes and paleoenviroment. The result shows that n-alkanes is in the range of nC₁₅~nC₃₃ and n-alkane distribution patterns are characterized by two modes. The first mode belongs to the higher molecular with MH being nC₂₅~nC₂₇, CPI> 1 and with remarkable odd-even dominance.They are of terrigenous plant origin. The second one belongs to lower carbon range with MH being nC₁₇~nC₂₀, CPI> 1 and with indistinct odd-even dominance. Therefore they are contributed by marine biological inputs. The contribution of land origin is larger than that of marine source. Pr/Ph is lower than 1 in the investigated area, which indicates the depositional environment of reducing reaction with lower oxygen. The result of factor analysis has good agreement with composition characteristics of n-alkanes in the sediment.