Organic geochemical characterization on a seal excrement sediment core from Fildes Peninsula, Western Antarctica

摘要

Organic geochemical analysis was performed on a sediment core HN1 from Fildes Peninsula on King George Island,Western Antarctica.Short-chain n-alkanes were the main components of the aliphatic hydrocarbons present,and they were likely to be from algae and bacteria;n-C23 was likely derived from moss.Fecal sterols and phytol dominated the alcohol composition,and may have come from seal feces and vegetation,respectively.The fluctuations in their concentrations generally have responded to historical changes in the ecosystems near the region.The even-carbon fatty acids,such as n-C16,n-C18 and n-C24,dominated the alkenoic acid composition,which mainly originated from bacteria,moss and zooplankton.The low concentrations of unsaturated fatty acids showed a predominance of C16:1 and C18:1 unsaturated acids,and demonstrated that the sediment was well preserved and had a simple and stable source of organic materials.