Schematic diagram of the modified weathering degree variation at different depths. In this diagram, for CE6, the pre-sampling maturity is derived from sampling site 0003, while the post-sampling maturity is derived from the scooped sample; for CE5, the pre-sampling maturity is derived from sampling sites 0009, 0010, 0012, and 0017, and the post-sampling maturity is derived from sampling sites 0014, 0015, and 0016.