CLP last 800 kyr S(z)

Zhaojiachaun, Fuxian and Luochuan sections S(z) compilation.Data Sources:The depth, age, stable isotopes, magnetic susceptibility (Xlf), soil respiration (Sz), and mixing ratio (R) parameters are compiled from the following sources (the header is Line 1):Lines 2–10 and 37–67: Published in Da et al., 2025.Lines 87–100: Published in Da et al., 2019.Lines 11–36 and 68–86: Previously unpublished; newly measured for this study following the exact analytical workflow described in Da et al., 2025.Note on Elements and Grain Size: Regardless of the publication source of the isotopes/Sz data, all element concentration data (aFe, aSi, aAl, fFe) and grain size data (D) across all rows were newly measured for this study.Ice Core CO2 data are interpolated from Bereiter et al., 2015.Column Definitions and Units:Sample_ID: Unique identifier for each paleosol sample.Depth(m): Stratigraphic depth of the sample (meters).Age(Ma): Estimated age of the sample (Million years ago).Sz: Concentration of soil-respired CO₂ (ppm).Sz_std: 1σ uncertainty of Sz (ppm).Xlf: Low-frequency magnetic susceptibility.d13Cc: Carbon isotopic composition of pedogenic carbonate (‰, VPDB).d18Oc: Oxygen isotopic composition of pedogenic carbonate (‰, VPDB).d13Co: Carbon isotopic composition of soil organic matter (‰, VPDB).R: Mixing ratio of atmospheric CO₂ versus soil-respired CO₂ in the soil pore space.R_std: 1σ uncertainty of the mixing ratio R.CO2_ice: Independent atmospheric CO₂ concentration target derived from ice cores (ppm).aFe, aSi, aAl: Amorphous iron, silicon, and aluminum concentrations, respectively (mass %, quantified by their corresponding oxides).fFe: Free iron oxides concentration (mass %, quantified by its corresponding oxide).aFe_std, aSi_std, aAl_std, fFe_std: 1σ uncertainties of the element concentrations.aFe/aSi, aFe/aAl, aSi/aAl, aFe/fFe, aSi/fFe, aAl/fFe: Calculated stoichiometric ratios of the respective amorphous/free element concentrations.aFe/aSi_std, aFe/aAl_std, aSi/aAl_std, aFe/fFe_std, aSi/fFe_std, aAl/fFe_std: 1σ uncertainties of the elemental ratios, propagated using a Taylor expansion series.CO2: Calculated atmospheric CO₂ concentration using the paleosol barometer (ppm).CO2_std: 1σ uncertainty of the calculated atmospheric CO₂ (ppm).D: Volume moment mean grain size, D[4, 3] (μm).D_std: 1σ uncertainty of the grain size measurement (μm).Da, J., Zhang, Y. G., Li, G., Meng, X. & Ji, J. Low CO2 levels of the entire Pleistocene epoch. Nat. Commun. 10, 4342 (2019).Da, J. et al. No apparent state-dependency of equilibrium climate sensitivity between the Pleistocene glacial and interglacial climate states. Nat. Commun. 16, 6608 (2025).Bereiter, B. et al. Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present. Geophys. Res. Lett. 42, 542–549 (2015).