FIGURE 7.5 Grain size variations at Baoji, Loess Plateau, north central China, compared to the 41,000- and 100,000-yr periodicities associated with variations in obliquity and eccentricity. Grain size variations are represented here by the ratio of the fraction of <2 pm grains to >10 pm; thus higher ratios represent a finer size distribution. Dashed lines show the filtered series bandpassed at 41 ka and 100 ka.A strong coherence between the loess record and the 100,000-yr period is noticeable over the last 0.6 Myr whereas prior to that the record has a stronger 41 kyr signal (back to -1.6 Myr).The earliest I Myr of the record is poorly correlated with both frequencies (Ding et al„ 1994).

Susceptibility (10-8m3kg-i)

years B.P.

Susceptibility (10-8m3kg-i)

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