底栖有孔虫壳体Mg/Ca是重建深层水团古温度的主要指标。通过分析表层沉积物样品中底栖有孔虫Uvigerina peregrina壳体的Mg/Ca和δ18 O,探讨了"Mg/Ca古温度重建方法"在白令海低温水体中的可行性及其转换函数。结果表明,利用U.peregrina壳体δ18 O换算的"结壳温度"明显低于"现代水团温度",不能客观反映温度对Mg/Ca的控制作用;可能受季节性变化的影响,水深小于150m样品中U.peregrina壳体的Mg/Ca与"现代水团温度"之间并没有表现出明显的相关性,但是,在深海区两者之间却呈现出良好的指数关系:Mg/Ca=0.69*e0.43*T。该公式指出白令海低温水体中Mg/Ca对温度的敏感性约为43%℃-1,由其估算的温度误差约为0.2℃。
The Mg/Ca ratio of benthic foraminiferal shells was often used as a paleo-temperature proxy for the deep water mass. In this study, we used the Mg/Ca and δ18O of the benthic foraminifera Uvigerina peregrine to calibrate the Mg/Ca thermometry so as to reveal its feasibility in the Bering Sea. The results show that the calcification temperature calculated with δ18O is much lower than the modern temperature of the water mass, and can not objectively reflect the control of temperature over the Mg/Ca. There is no evi- dence to relate the Mg/Ca with the modern temperature of water mass in the region if the water depth is shallower than 150 m. In the deep sea, however, a good exponential function expressed as Mg/Ca=0.69 e0.43. T was discovered with a standard error of 0.2 ℃and the Mg/Ca-temperature sensitivity may reach 43℃ 1at low temperature in the Bering Sea.