Based on the content of
The lower limit of the ferruginous argillans of S4 is about 0.5 m below the bottom of the Bt horizon. These removal depths are greater than that in the subtropical dystric cambisols in the Hanzhong area (Table 4) and Sihong area (Table 4), where the mean annual temperature is 15 °C and the mean annual RGB-286638 is 890 mm/year (Table 4; Li et al., 1983 and Xiong and Li, 1987). The depth is similar to that in the dystric cambisols in the Liuhe area of Jiangsu province (Table 4), where the mean annual temperature is 16 °C and the annual precipitation is 1050 mm/year (Li et al., 1983 and Xiong and Li, 1987). The removal depth of the ferri-argillans (Table 4) further suggests a greater weathering intensity of S4. The thickness of the weathered loess in S4 is also greater than that in the dystric cambisols in the Hanzhong and Sihong areas and similar to that in the dystric cambisols in the Liuhe area (Table 4). This suggests that the mean annual temperature and precipitation would have been at least 16 °C and 1000 mm/year during the development of S4. These values are 3 °C and 400 mm/year higher than those in the Guanzhong Plain.