长链烯酮的组合特征及其对盐度和母源种属指示意义的研究进展

Progress of Compositions and Indications of Long-Chain Alkenones

长链烯酮是一类组成丰富且受到广泛研究的生物标志物,已成功应用于古海洋环境重建工作。近来海洋和湖泊的沉积物、颗粒物以及相应的母源藻类培养实验的研究结果都显示,除U^K37和U^K′37指示温度外,长链烯酮化合物还可用于指示其他生态环境因子的变化。长链烯酮类化合物已经从最初的C37-C39组分扩展至近年来发现的C35-C42的甲基烯酮或乙基烯酮。在此总结了除温度指标外,近年来在海洋和湖泊中发现的长链烯酮的几种组合特征,及其可能发展出的指示环境盐度(%C37:4,C36:2乙基烯酮)、母源种属(C37/C38烯酮比值,C38甲基烯酮)变化以及定量区分不同类型定鞭藻合成的长链烯酮(RIK37、RIK38Et)的潜在指标。长链烯酮的组合特征和潜在指标研究可为重建长时间尺度海洋和湖泊环境演变提供新的手段,也有助于揭示生态环境变化的机制。

Long-chain alkenones and relevant alkenone index have been widely applied to reconstruct paleoceanographic environments.In addition to U^K 37 SST proxy based on C 37 alkenones,the evidences from sediments and particulate organic matter in both marine and lacustrine settings and algae culture reveal that long-chain alkenones have potential to indicate the other environmental changes.Recent studies also found long-chain alkenones with C 35 to C 42 carbon chain.In this paper,it is summarized that the compositions of long-chain alkenones in marine and lacustrine environments and potential alkenone-based proxies for salinity(i.e.%C 37:4,C 36:2 ethyl alkenone)and alkenone-producing algaes(i.e.the ratio of C 37 to C 38 contents,C 38 methyl alkenones,RIK 37,RIK 38Et).The study of compositions and potential indications of long-chain alkenones can be helpful to reconstruct long-term changes in marine and lacustrine environments,and to further reveal the mechanism of ecological environmental change.