Fig. 6

(a) Stratigraphic column at location SZ6. (b) Stratigraphic column, photograph, soft X-ray image, CT image, and results of grain-size analysis at location SZ7. The discontinuity exists at a depth of 20 cm below the ground surface, as the core sediment was divided into two acrylic cases at depths of 0–20 cm and 20–40 cm for CT and soft X-ray imaging.