摘要
对西太平洋暖池区MD97-2140柱状样1.75Ma以来的钙质超微化石进行了氧碳同位素分析.结果表明超微化石δ18O值与浮游有孔虫Globigerinoidesruberδ18O值在变化趋势和周期上都具有明显相似性.根据超微化石δ18O值也可以划分出59个氧同位素期,1748ka到900ka期间超微化石δ18O值的变化周期以41ka为主,而850ka到6ka期间则以100ka为主.这说明超微化石氧同位素分析可以像有孔虫氧同位素分析一样在大洋地层学和古海洋学、古气候学研究中发挥重要作用.超微化石δ13C值变化则呈现阶段性变化的特点,以900ka,480ka和250ka时间面为界,可分四大阶段.同时,MD97-2140柱状样超微化石δ13C值的这种变化规律与邻近ODP807站揭示的海水初级生产力变化趋势极为相似,意味着超微化石δ13C值是反映海水初级生产力变化的一项重要指标.
Oxygen and carbon isotopic analyses have been carried out on calcareous nannofossils from core MD97-2140 in the Western Pacific warm pool. The results demonstrate that the δ^18O values of calcareous nannofossils for the past 1.75 Ma vary systematically with δ^18O values of planktonic foraminifer Globigerinoides ruber from the same core. The δ^18O records of calcareous nannofossils show a dominant 41 ka peak between 1 478 and 900 ka and a 100 ka peak between 850 and 6 ka, and 59 isotope stages can be recognized. The similarity between δ^18O records of planktonic foraminifera and nannofossils implies that calcareous nannofossil δ^18O can also play an important role in stratigraphic and palaeoceanographic studies. The δ^13C records of nannofossils can be divided into four major stages respectively at the boundaries 900 ka, 480 ka and 250 ka. The trends of the nannofossil δ^13C records from MI397-2140 are similar to primary productivity variations at ODP site 807, also located in the Western Pacific warm pool, indicating that narmofossil δ^13C can be used as an indicator of sea surface palacoproductivity.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2005年第5期559-564,603,共7页
Earth Science-Journal of China University of Geosciences
基金
国家自然科学基金项目(Nos.40376019
40331002
40125015)
国家重点基础研究专项项目(G2000078502)
创新研究群体科学基金项目(No.40321603).
关键词
氧碳同位素
钙质超微化石
第四纪
西太平洋暖池
oxygen and carbon isotope~ calcareous nannofossils~ Quaternary
Western Pacific warm pool
