Geochemical distribution and genesis of selenium-rich soils in Maojie Town on the Yunnan low-selenium belt

Understanding the distribution patterns and genesis of selenium-rich soils, a valuable natural resource, constitutes a fundamental prerequisite for their effective development and utilization. To investigate the geochemical distribution characteristics and influencing factors of selenium-rich soil in Maojie Town, this study conducted a land quality geochemical survey and collected rock and soil samples. Selenium concentrations were determined using atomic fluorescence spectrometry (AFS), and multivariate statistical regression analysis was employed to analyze the data. The results showed that the selenium content in the soils of Maojie Town ranged from 0.13 to 0.85 mg·kg^-1, with an average concentration of 0.39 mg·kg^-1. The selenium distribution was uneven, with selenium-rich soils mainly concentrated in the central part of the town. The formation of selenium enrichment in Maojie Town is attributed to the geological background of Mesoproterozoic slightly metamorphosed rocks, high-altitude forestlands with abundant organic matter and slow decomposition rates, and the fixation and adsorption effects of clay minerals and acidic soils. These findings provide a scientific basis for the development and utilization of selenium-rich soils and the socioeconomic development of the region.