摘要
对西太平洋暖池核心区MD01 2386柱状样最上部5m进行了高分辨率的浮游有孔虫Globigerinoidesruber和Pulleniatinaobliquiloculata的氧、碳稳定同位素分析,结合AMS14C测年,研究表明其属于末次盛冰期—全新世的沉积。赤道西太平洋海区末次盛冰期以来δ18O值显著降低,但有几次回返事件。表层浮游有孔虫G.ruber比次表层温跃层属种P.obliquiloculata对于环境变化的响应要快,但后者变化的幅度较大。这两个种的氧、碳同位素差值反映出温跃层深度自末次盛冰期以来逐渐加深,并存在周期性的回返事件,说明西太平洋暖池晚第四纪冰期旋回存在气候不稳定性。
The upmost 5 m of core MD01-2386 from the west Pacific warm pool was studied for determining the variability of the depth of thermocline(DOT) since the last glacial maximum at centennial scales based on high-resolution oxygen and carbon stable isotopes of planktonic foraminifers Globigerinoides ruber and Pulleniatina obliquiloculata with the AMS^(14)C age datings.It has been demonstrated that the δ^(18)O in the west Pacific significantly decreased since the last glacial maximum together with,however,a few return events such as the cooling events during the Younger Dryas period of 13.7～12.2 cal.kaBP and at 6.1 and 8.1 cal.kaBP.Moreover,surface dwelling species G.ruber responds to the environmental changes more quickly than the subsurface thermocline-dwelling species P.obliquiloculata,though the latter has a larger amplitude of change.Especially,the DOT,reflected by the difference between the oxygen and carbon isotopes of the two species,displayed a trend of gradually deepening since the last glacial maximum coincident with periodical returen events.This indicates the climatic unstability of the west Pacific warm pool during the late Quaternary glacial cycles.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2004年第2期67-71,共5页
Marine Geology & Quaternary Geology
基金
国家自然科学基金资助项目(40125015
40321603)
国家重点基础研究发展规划项目(G2000078502)
教育部霍英东基金资助项目(81015)
关键词
稳定同位素
碳
氧
末次盛冰期
浮游有孔虫
温跃层
stable isotope
planktonic foraminifer
short-term climatic events
last glacial cycle
west Pacific warm pool
