Abstract
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 profile at Xifeng. A comparison of the last 160 ka is made between the susceptibility profile and the carbon dioxide and deuterium concentration 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-weighted time scale is preferable to astronomical tuning to the 41 ka component. The loess susceptibility signal is found to lead the smoothed, stacked oxygen isotope records from marine cores by about 22 ka. We propose a model involving rapid and slow responses of continental and marine 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 seems to lag the eccentricity variation 60–85 ka throughout the Brunhes Chron.
Published Version
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