Paleoclimatic significance of eolian carbonates supplied to the Japan Sea during the last glacial maximum

Laminated sediments deposited under anoxic bottom waters in the Japan Sea d uring the last glacial maximum (LGM) contain extremely well preserved calca reous microfossils and eolian carbonates. The radiocarbon age-difference be tween bulk sediment and monospecific planktonic foraminifera in discrete la minae from a core in the southern Japan Sea implies that similar to 40% of the total carbonates in the sediments at the LGM are of eolian origin. Extr apolation of this result yields a rate of supply of eolian carbonates of si milar to 2800 tons d(-1) to the entire Japan Sea during the LGM. The climat ic significance of this flux potentially lies in its broader geographic ext ension, particularly in the interaction of the carbonate-bearing dust with shallow, corrosive North Pacific waters and with rain in the atmosphere. By increasing the alkalinity of such waters and by enhancing the biological p ump the dust flux could have increased CO2 absorption by both the ocean and rain during the LGM.