Distribution,ecology,and oxygen and carbon isotope characteristics of modern planktonic foraminifers in the Makarov Basin of the Arctic Ocean  

作　　者：Xuan Ding Rujian Wang Haifeng Zhang Zhencheng Tao 

机构地区：[1]School of Marine Sciences, China University of Geosciences [2]State Key Laboratory of Marine Geology, Tongji University [3]The Second Institute of Oceanography, SOA [4]Institute of Oceanology, Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2014年第7期674-687,共14页

基　　金：supported by the National Natural Science Foundation of China(41030859 and 41211120173);the Chinese Special Project of Arctic Marine Geology Investigation(CHINARE 2013–03–02)

摘　　要：The Arctic region, with magnificent ice cover on the surface of the Arctic Ocean and adjacent seas, is not only extremely sensitive to but also has strong amplification effects on climate change. Observations during the past decades have documented substantial retreat and thinning of the Arctic sea-ice cover, a process that is accelerating. Its feedback and impact on the global climate has become an important subject of current climate change research. Calcite tests of planktonic foraminifers are major constituents in pelagic sediments, and they provide valuable materials for the reconstruction of past oceanographic conditions. However, research is still sparse in the Arctic sea area because of limited availability of the materials for investigation. Here, we present a study of modern foraminifers from the plankton tow samples taken in the Makarov Basin of the Arctic Ocean during the fourth Arctic expedition of China. We have analyzed ecological information stored in the modern planktonic foraminifers and in their stable isotope signals, and established a relationship between the distribution of the main taxa and the environment. Our main observations are as follows:(1) in the Makarov Basin, the polar species Neogloboquadrina pachyderma(sinistral coiling) dominates the [150 lm planktonic foraminiferal assemblages.(2) The planktonic foraminifers live mainly in the upper halocline at a water depth of 50–100 m and less in the depth interval of 100–200 m.(3) Temperature change in the halocline can affect the absolute abundance of planktonic foraminifers and their distribution in the water column. The warmer halocline is more favorable to the development of planktonic foraminifers.(4) A lighter d18O value(2.11 %) of N. pachyderma(sin.) is recorded in the depth interval of 100–200 m, which is likely related to the isotopically light brines separated out during sea ice freezing. The relatively heavy d18O value(1.68 %–2.68 %, average 2.27 %) in the depth interval of 50–100 m may be influenced by the low salinitThe Arctic region, with magnificent ice cover on the surface of the Arctic Ocean and adjacent seas, is not only extremely sensitive to but also has strong amplifica- tion effects on climate change. Observations during the past decades have documented substantial retreat and thinning of the Arctic sea-ice cover, a process that is accelerating. Its feedback and impact on the global climate has become an important subject of current climate change research. Calcite tests of planktonic foraminifers are major constituents in pelagic sediments, and they provide valu- able materials for the reconstruction of past oceanographic conditions. However, research is still sparse in the Arctic sea area because of limited availability of the materials for investigation. Here, we present a study of modem fora- minifers from the plankton tow samples taken in the Makarov Basin of the Arctic Ocean during the fourth Arctic expedition of China. We have analyzed ecological information stored in the modem planktonic foraminifers and in their stable isotope signals, and established a rela- tionship between the distribution of the main taxa and theenvironment. Our main observations are as follows： （1） in the Makarov Basin, the polar species Neogloboquadrina pachyderma （sinistral coiling） dominates the 〉150 μm planktonic foraminiferal assemblages. （2） The planktonic foraminifers live mainly in the upper halocline at a water depth of 50-100 m and less in the depth interval of 100-200 m. （3） Temperature change in the halocline can affect the absolute abundance of planktonic foraminifers and their distribution in the water column. The warmer halocline is more favorable to the development of plank- tonic foraminifers. （4） A lighter 6180 value （2.11‰） of N. pachyderma （sin.） is recorded in the depth interval of 100-200 m, which is likely related to the isotopically light brines separated out during sea ice freezing. The relatively heavy δ18O value （1.68 ‰-2.68‰, average 2.27‰） in the depth interval

关 键 词：浮游有孔虫 同位素特征 生态信息 北冰洋 盆地 调制解调器 北极地区 北极海冰 

分 类 号：Q915[天文地球—古生物学与地层学]