Fig. 4. Dingxi Section: field-observed pedostratigraphy and laboratory data. Md (µm): median size; <10 µm (%): percentage of <10-µm fraction; <2 µm (%): percentage of <2-µm fraction; CaCO₃ (%): percentage of carbonate; : magnetic susceptibility (10^–7 m³ kg^–1); and _fd: frequency-dependent susceptibility (%). Three shaded strips (I, II, III) are paleosol zones (S1S1, S1S2, S1S3). Three arrows within the three shaded strips indicate carbonate leaching and accumulation in the three paleosols.