Possible origin of with a remarkable even-to-odd predominance in recent marine sediments

A new regional, mid-Holocene palaeoprecipitation signal of the Asian Summer Monsoon

“…The predominant n-fatty acids are C 22-30 homologues with an even-over-odd preference (CPI 10.4-12.9, calculated as for the n-alcohols), typical of sediments containing terrigenous, higher plant-derived lipids (Collister et al, 1994;Eglinton and Hamilton, 1967;McCaffrey et al, 1991). These CPIs are significantly >1, also suggesting that the acid fraction is not derived from the petroleum source which dominates the saturated hydrocarbon fractions (Freeman and Colarusso, 2001;Nishimura and Baker, 1986). The CPIs exhibit no systematic temporal variability, which indicates both that they have undergone no significant degradation over time and that these epicuticular leaf waxes were not retained for lengthy periods in terrestrial soil (Hedges and Oades, 1997).…”

Use of aliphatic hydrocarbons to infer terrestrial organic matter in coastal marine sediments off China

“…Short chain n-alkanes (<C 21 ) may originate from bacteria (Nishimura and Baker, 1986), algal and/or phytoplanktons (Youngblood and Blumer, 1973). Aliphatic hydrocarbons of bacterial and planktonic origins are predominated by even (n-C 14 , n-C 16 and n-C 18 ) (Nishimura and Baker, 1986) and odd (n-C 15 , n-C 17 and n-C 19 ) (Youngblood and Blumer, 1973) carbon n-alkanes, respectively.…”

“…Aliphatic hydrocarbons of bacterial and planktonic origins are predominated by even (n-C 14 , n-C 16 and n-C 18 ) (Nishimura and Baker, 1986) and odd (n-C 15 , n-C 17 and n-C 19 ) (Youngblood and Blumer, 1973) carbon n-alkanes, respectively. The CPI [14][15][16][17][18][19][20] values for aliphatic hydrocarbons of nonsilliceous planktonic origin were greater than 1 (Doskey, 2001;Youngblood and Blumer, 1973).…”

Long-chain anteiso compound series found in acidified freshwater lake sediments in Japan: Lake Tazawa-ko.

“…Eganhouse et al, 1981) was found and the human activities around the lake are very limited, the origin of n-alkanes with low CPI values may not be attributed either to anthropogenic pollution or to diagenetically altered lipids from eroded sedimentary rocks (Giger et al, 1980). Recent findings of n-alkanes in modern sediments often dominated by even-numbered carbon-chains (Nishimura and Baker, 1986;Grimalt and Albaiges, 1987;Parrish et al, 1992) and the stable carbon isotopic analysis of individual al kanes (Kennicutt and Brooks, 1990) suggested a widespread occurrence of certain biota which uniquely synthesize even-numbered long-chain alkanes. Quantitative increase of n-alkanes in the surface sediment and sediment trap samples (Table 1), where a low CPI was observed, implied an addition of newly produced n-alkanes with a small odd to even preference.…”