We performed organic geochemical analysis on a sediment core HN1 from Fildes Peninsula in King George Island, Western Antarctica. The results showed that the aliphatic hydrocarbons were mainly consisted of short-chain n-alkanes which likely derived from algae and bacteria and n-C23 which likely derived from moss. Meanwhile, the concentration of fecal sterols and phytol which mainly came from seal feces and vegetation were high in the alcohols and the fluctuations of them in the catchment core might respond to the historical of zoology changes near the sediment. Furthermore, the even-carbon fatty acids, such as n-C16, n-C18 and n-C24, dominated alkenoic acids and they principally originated from bacteria, moss or zooplankton. However, the concentration of unsaturated fatty acids was low. And they were mainly predominated by C16: 1 and C18: 1 acids which showed good preservation and simple sourses of the sediment. In summary, the organic geochemical compositions indicated that the organic matters of HN1 sediment were well protected and mainly derived from seal feces. And the sedimentary environment of HN1 changed in different depths with active bacteria and fungi.%本文研究了位于西南极菲尔德斯半岛海豹粪土的沉积泥芯HN1的分子地球化学组成特征.HN1沉积物的正烷烃以短链及n-C23为主,主要来源可能为湖相沉积的藻类、细菌和苔藓的输入.醇类组分以高浓度的植物甾醇和粪便甾醇为主,分别代表了植被和海豹粪土沉积的输入,指示了研究区域历史时期的生态变化.脂肪酸组分偶奇优势明显,以C16,C18和C24一元饱和脂肪酸为主,主要来源可能是浮游动物、细菌及苔藓;不饱和脂肪酸含量很低,以C16:1和C18∶1为主,表明沉积源单一稳定,无大波动.综合HN1的生物标志物特征,沉积柱保存较好,其各个组分所反映的沉积物有机质来源统一,主要来源于海豹粪、细菌、藻类和苔藓;沉积环境在不同深度有变化,底层细菌和真菌的活动比表层高.
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