摘要
317-82-25和NS86-43孔岩芯分别取自南海北部和南海南部海底表层沉积物,V24-134孔岩芯取自菲律宾东苏禄海。通过对浮游有孔虫Pulleniatina obliquiloc(?)-late、Globorotalia menardii 和Neogloboquadrina dutertrei 的氧同位素分析,建立了氧同位素阶段,表明约60000年以来南海沉积物中有孔虫的氧同位素变化与世界各大洋相似,但有较大的变化幅度。这种差异可能是南海海水温度在冰期—间冰期较大幅度变化的结果。南海沉积速率明显大于远洋沉积速率,说明南海沉积物主要是陆源的。
The core 317-82-25 (19°30.13′N,117°53.02′E,3205m) and NS86-43 (07°01.39′N,110°23.78′E,1763m) were derived from the north and south of the South China Sea respectively,andthe core V24-134 (08°50′N,119°14′E,2019m) was derived from the Sulu Sea.The coresmainly consist of foraminiferal calcareous clay and silts.Oxygen isitopic inalysis was sarriedout on the planktonic foraminifera Pulleniatina obliquiloculata,Globorotalia menardii and Neo-globoquadrina dutertrei.The oxygen isotopic records of three planktonic species in each corehave a similar variation.Three oxygen isotopic stages (1 to 3) have been recognized in theisotopic records of the core 317-82-25 and NS86-43.The bottom ages of the core 317-82-25 andNS 86-43 are about 53000 a B.P.and 65000 a B.P.respectively.The fact that averages ofthe sedimentation rates in the sites of the core 317-82-25 and NS86-43 which are estimated as5.5 and 4.6 cm/10~3a since about 60000a B.P.respectively are greater than that in pelagicregions reflects that the sediments in the South China Sea have mainly been derived from ter-restrial sources.The foraminiferal oxygen isotopic records of two cores from South ChinaSea are in general agreement with that of the cores from the deep-sea since about 60000a B.P.But the amplitudes of (?)O variatiins are greater than that in the pelagic cores from the Trop-ical Pacific Ocean.It might be resulted in that the amplitude of the temperature changesof the South China Sea was greater than one of the Tropical Pacific Ocean during glacial-interglacial because of the strong winter monsoon during glacial period.
出处
《第四纪研究》
CAS
CSCD
1991年第1期55-63,共9页
Quaternary Sciences
基金
国家自然科学基金
