Fig. 2. The geographic variations of the S1 pedocomplex profiles from northwest to southeast across the Chinese Loess Plateau: all three paleosols (S1S1, S1S2, S1S3) and two interbedding loess units (S1L1 and S1L2) are preserved at the Lanzhou and Dingxi sections; the S1L2 loess unit was annexed by the S1S2 paleosol development at the Qinan section and both the S1L2 and S1L1 loess units were annexed by later paleosol development at the Tianshui sections; the S1 pedocomplex at the Lantian section is a single composite paleosol profile.