南海南部普林虫与“中更新世革命”

对南海南部ODP 1143站2.1 Ma以来沉积物中的浮游有孔虫群进行研究, 发现在冲绳海槽及南海北部普遍被认为是黑潮标志种的Pulleniatina obliquiloculata在中更新世革命(MPR)前后对冰期旋回的响应截然相反; 且在MPR之后的变化与南海北部和冲绳海槽相反, 即冰期时含量高而间冰期时低.交叉频谱分析和相位分析的结果也证实了ODP 1143站P.obliquiloculata与全球冰量变化之间的上述关系.该种在MPR前后冰期旋回的转变, 可能是由于MPR之后南海南部在冰期时切断了与印度洋之间的海水交换, 或者是冰期时海水盐度增加等因素引起的上部水体结构的重大改观所致. 

Mid-Pleistocene Revolution Recorded by Pulleniatina obliquiloculata in the Southern South China Sea

Planktonic foraminifers from ODP Site 1143, southern South China Sea (SCS), were analyzed to reveal their response to glacial cycles in the past 2.1 Ma. Pulleniatina obliquiloculata, a widely-accepted indicator of the Kuroshio, shows completely reverse fluctuations, with high abundance in glacials, in southern SCS to those in the Okinawa trough and northern SCS since the Mid-Pleistocene Revolution (MPR). Before the MPR, P.obliquiloculata is abundant in interglacial intervals. Cross-spectral and phase analyses between P.obliquiloculata and δ18O confirmed the observations depicted above. The authors ascribed the transition of P.obliquiloculata's response to glacial cycles in southern SCS to a profound change in the regional upper ocean structure, probably related to glacial separation of the southern SCS from the Indian water and to higher surface salinity during glacial times after the MPR.