Fig. 4. Spectral analysis and sedimentation rate evaluation of the log₁₀(Ca) (a–e) and magnetic susceptibility (MS) (f–j) series.

a, f Lomb-Scargle spectra of the detrended log₁₀(Ca) (a) and detrended MS (f) series shown with confidence levels test against robust first-order autoregressive AR(1) red noise models. Significant periodicities are labeled with the unit of meters. The 1-slice correlation coefficient (COCO) spectra of the detrended log₁₀(Ca) (b–d) and detrended MS (g–i) series. Correlation coefficient (b, g), null hypothesis (H₀) significance level (c, h), and number of contributing astronomical parameters (See Supplementary Information for details) (d, i) are shown. e, j Average spectral misfit (ASM) of the detrended log₁₀(Ca) (e) and detrended MS (j) indicate roughly consistent mean sediment accumulation rate of 10–16 cm/kyr.