Abstract: In order to quantitatively analyze the effects of geographical factors on the spatial variation of copper (Cu), cobalt (Co), molybdenum (Mo) and zinc (Zn) in surface soil, 156 soil samples from the Jiangjin district with high longevity population in Sichuan Basin were collected and measured. The spatial variation and driving factors of Cu, Co, Mo and Zn in surface soil were studied using mathematical statistics, geostatistics and geographic detectors. The mean content of Cu, Co, Mo and Zn in surface soil, Jiangjin district were 27.0×10^-6, 18.5×10^-6, 0.4×10^-6 and 216.8×10^-6, respectively, and were 1.19-fold, 1.45-fold, 0.20- fold and 2.17-fold of background values of China soils. The variation coefficients of soil Cu, Co, Mo and Zn content were in the moderate intensity. Whereas, spatial distribution of Zn and Mo in surface soil from the Jiangjin district was more uneven. As a whole, the content of Cu, Co, Mo and Zn in top soil from northern Jiangjin was higher than those of southern Jiangjin. Iron (Fe), manganese (Mn), parent rocks and soil types were driving factors affecting spatial variation of the soil Cu, Co, Mo and Zn but vary in extent. Generally, the iron (Fe) and manganese (Mn) in soil exerted the highest effect and played an important role in the distribution, enrichment, and migration of Cu, Co, Mo and Zn in top soil from the Jiangjin district, Sichuan Basin.

Key words: Sichuan Basin, spatial variation, essential biological trace element, driving factors, Jiangjin district