Long-Chain Alkenones in the South Yellow Sea Sediments and Their Indicative Significance for Haptophytes Species  

作　　者：XU Yakun YANG Xinxin XIAO Rui XING Lei 

机构地区：[1]Key Laboratory of Marine Chemistry Theory and Engineering Technology,Ministry of Education,Ocean University of China,Qingdao 266100,China [2]Laboratory of Marine Ecology and Environment Science,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266071,China

出　　处：《Journal of Ocean University of China》2024年第5期1287-1296,共10页中国海洋大学学报（英文版）

基　　金：funded by the National Natural Science Foundation of China(Nos.41876073,92058207);the National Basic Research Program of China(973 Program No.2010CB428901).

摘　　要：Long-chain alkenones(LCAs)have been widely used as important biomarkers in palaeoceanographic studies.However,the commonly used LCAs proxies are mainly based on C_(37) alkenones,and it is still lack of the studies about the distribution and in-dications of LCAs with different chain lengths other than C_(37) alkenones.Here,the composition and distribution of LCAs were ana-lyzed in surface sediments from the southern Yellow Sea(SYS)and a sedimentary core(A02-C)from the central Yellow Sea(YS)mud area.The results showed that C_(37),C_(38) and C_(39) alkenones were the major LCAs in surface sediments of the SYS,and the relative contents of C_(38:2)Et,C_(37:2)Me,C_(37:3)Me,C_(38:2)Me,C_(38:3)Et,C_(38:3)Me,C_(39:2)Et and C_(39:3)Et were 18.3%-59.8%,22.6%-41.2%,7.4%-23.0%,6.6%-15.4%,3.8%-13.3%,3.6%-8.7%,2.8%-6.0% and 0.7%-3.0%,respectively.Then the relationships of U_(38Me)^(K)-U_(38Et)^(K) and U_(37)^(K')-U_(38Et)^(K) indicate that LCAs are mainly derived from Emiliania huxleyi(E.huxleyi).High ratios of total C_(37) alkenones to total C_(38) alkenones(K_(37)/K_(38))(1-1.2)were found in the central SYS,corresponding to the relatively high abundance of E.huxleyi;while low ratios of K_(37)/K_(38)(0.7-0.9)were observed at nearshore area of the SYS where Gephyrocapsa oceanica(G.oceanica)has rela-tively high abundance.The spatial distribution of K_(37)/K_(38) ratio is also consistent with that of coccolithophores nannofossil in the sediments.In addition,K_(37)/K_(38) ratio in core A02-C varied from 0.7 to 1.1 with a gradual decreasing trend during the past 5.5 kyr.This suggests that the relative abundance of E.huxleyi decreased gradually,caused by the changes in the Yellow Sea Warm Current(YSWC)and the East Asian Winter Monsoon(EAWM)during this period.

关 键 词：ALKENONES southern Yellow Sea SEDIMENT Yellow Sea Warm Current 

分 类 号：P736.41[天文地球—海洋地质]