Geochemical Characteristics and Influencing Factors of Germanium in Surface Soil in Yongchuan District, Chongqing

<p indent="0mm"> Germanium (Ge) is an important trace element to the environment and humans, and Ge-rich soil is valuable for agricultural development. Yongchuan District is a key agricultural region in Chongqing city, and this study aims to reveal the geochemical characteristics and influencing factors of Ge in surface soil in this area based on the results of a land quality geological survey. The results showed that the total concentration of Ge in the surface soil ranged from 0.10 to <sc>8.47 mg/kg,</sc> with an average value of <sc>1.43 mg/kg.</sc> Compared with other typical Ge rich areas, the level of Ge content in some area of this study is relatively high. The calculated land with Ge-rich soil is <sc> 785.13 km², </sc> accounting for about 64% of the total area. Germanium-rich soils are mainly distributed in the Middle Jurassic Shaximiao Formation, Lower Ziliujing Formation, and Upper Triassic Xujiahe Formation. Among them, the Ge content of sandstone is higher than that of carbonate rock. This indicates that the Ge content in soil is affected by different soil-forming host rocks to a certain extent. The Ge content was relatively enriched in soils with a medium-alkaline pH and a cultivated land use type. The high-value Ge area in the central part of the study area was greatly affected by human activities such as industry and agriculture. The results of this study can provide basic data for the biogeochemical research of Ge in soil systems, and provide guidelines for the scientific development and utilization of Ge-rich soil resources.