CALIBRATION OF MG/CA THERMOMETRY OF THE BENTHIC FORAMINIFERA FROM THE BERING SEA

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 evidence 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*e^0.43*T was discovered with a standard error of 0.2℃and the Mg/Ca-temperature sensitivity may reach 43%℃^-1 at low temperature in the Bering Sea.