Neo-Science of Natural History : Integration of Geoscience and Biodiversity Studies;Proceedings


Variations of Mass Accumulation Rates of Long Chain n-alkanes in the Northern North Pacific During the Last 350 kyrs

Ratnayake, Nalin P.;Suzuki, Noriyuki;Sawada, Ken;Okada, Makoto

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KEYWORDS : Long chain n-alkanes;Terrestrial organic matter;Northern North Pacific Ocean;Emperor Seamount;Mass accumulation rates


Land plant waxes preserved in the marine sediments are considered to be a useful proxy to reconstruct the terrestrial palaeoenvironments. Long chain n-alkanes were analysed to understand the historical variations of the supply of terrigenous organic matter during the last 350 kyrs. Results show that the mass accumulation rates (MARs) of the long chain n-alkanes tended to increase during glacial stages particularly during the last glacial period in the Emperor Seamount area of the northern North Pacific Ocean. Simultaneous increases in the amount of organic matter attached to eolian dust could have resulted in increased MARs of terrestrial organic matter during glacial stages (marine isotopic stages 2, 4, and 6). In contrast, decrease of aridity along with moderate westerly winds during the interglacial periods resulted in a lower rate of dust production and thus reduced transport of terrestrial organic matter towards the northern North Pacific Ocean.