CORRELATION OF THE MAGNETIC-SUSCEPTIBILITY STRATIGRAPHY OF CHINESE LOESS AND THE MARINE OXYGEN-ISOTOPE RECORD - CHRONOLOGICAL AND PALEOCLIMATIC IMPLICATIONS

The thick deposits of wind-blown silt of the Loess Plateau in central China constitute arguably the most important terrestrial record of the late Pliocene and Pleistocene climate. Magnetic susceptibility strati graphy has proven extremely useful for quantifying the palaeoclimatic record of Chinese loess, with intervals of high magnetic susceptibilit y corresponding to warm, humid interglacials and intervals of low susc eptibility to cooler, drier glacials. Several workers have noted that the magnetic susceptibility stratigraphy strongly resembles the marine oxygen isotope record, for which a high resolution chronology is avai lable from tuning to the frequencies of Earth orbital parameters. Atte mpts have been made to correlate the two records statistically and we use this approach to generate a new magnetic susceptibility time serie s for the central Chinese Loess Plateau. Our results suggest that the two records are sufficiently similar over the interval ca. 0-1.5 My BP for this approach to yield a useful age model for loess accumulation. Spectral analysis of the resulting magnetic susceptibility time serie s clearly shows that the growth of 100 ky variance, which occurs in th e marine oxygen isotope record after about 1 My BP, also occurs synchr onously in the magnetic susceptibility record, reinforcing recent sugg estions of a strong linkage between the high latitude northern hemisph ere and the Asian climate. We also show that a significant improvement in the strength of the loess magnetic susceptibility-marine oxygen is otope correlation occurs after about 1.5 My BP, which corresponds to a significant increase in the rate of sediment accumulation across the Loess Plateau.