南海南部粉红色Globigerinoides ruber冰期旋回及影响因素

GLACIAL CYCLES OF GLOBIGERINOIDES RUBER (PINK) AND ITS INFLUENCING FACTORS IN THE SOUTHERN SOUTH CHINA SEA

对南海南部ODP1143站氧同位素11—5e期大约2ka分辨率的粉红色Globigerinoidesruber进行分析,发现其冰期/间冰期旋回与代表全球冰量的底栖有孔虫氧同位素(δ18O)的变化相反,即在间冰期时含量低,而冰期时高,与其他海区的记录相反。海水表层温度和温跃层深度转换函数结果以及碎壳率的变化显示,在一定的温度背景下,温跃层深度的变化可能是控制粉红色G.ruber冰期旋回的主要因素,而这段时期南海南部溶解作用的影响则不明显。

Reverse variation of Globigerinoides ruber (pink) to ice volume change (represented by δ18O) is recorded during marine isotope stages 11—5e from ODP Site 1143 in the southern South China Sea (SCS), with resolution of ～2 ka. Its abundance was higher in the glacials and lower in the interglacials, showing a complete difference from the records from other regions. Sea Surface Temperature (SST), Depth of Thermocline (DOT) and fragmentation of planktonic foraminifer were calculated and compared, to discuss their effects on G.ruber (pink) change. SST and fragmentation showed little oscillations over most of the time interval, whereas DOT had strong fluctuation and was well correlated to G.ruber (pink). It is indicated that DOT was more likely to have the profound impact on G.ruber (pink) variation in the southern SCS.