IMPLICATION OF THE MAGNETIC-SUSCEPTIBILITY CURVE FROM THE CHINESE LOESS PROFILE AT XIFENG

A time scale derived by multiplying stratigraphic thickness of a layer by its magnetic susceptibility, with interpolation between the top (0 ka) and the B/M boundary (730 ka), is applied to the Chinese loess pr ofile at Xifeng. A comparison of the last 160 ka is made between the s usceptibility profile and the carbon dioxide and deuterium concentrati on profiles from the Vostok ice cores in Antarctica. Good correlations between these curves are found with +/- 10 ka differences in timing. Fast Fourier Transform analyses indicate that our susceptibility-weigh ted time scale is preferable to astronomical tuning to the 41 ka compo nent. The loess susceptibility signal is found to lead the smoothed, s tacked oxygen isotope records from marine cores by about 22 ka. We pro pose a model involving rapid and slow responses of continental and mar ine records to astronomical forcing. A correlation is made between the smoothed susceptibility curve and theoretical solutions for the long term variation of eccentricity. However, the susceptibility signal see ms to lag the eccentricity variation 60-85 ka throughout the Brunhes C hron.