Spatial and temporal distribution, geochemical characteristics of carbonatites and their relationship with U–REE mineralization in the Xiaoqinling area, Shaanxi Province

[ Objective ] Carbonatites, as magmatic-origin rocks, are crucial source rocks for uranium, rare earth, and other minerals. They are widely distributed in the Xiaoqinling region of Shaanxi, giving rise to numerous large to super-large carbonatite deposits of uranium, molybdenum, and rare earth, represented by Huayangchuan and Dashigou, attracting attention from scholars in recent years. Previous studies on carbonatite deposits in the area focused on petrology, mineralogy, genesis, and mineralization chronology. However, they were often limited to individual deposits, needing more regional cross-sectional comparative studies. [ Methods ] This study employs field geological surveys, petrographic analysis, and geochemical characterization of typical rocks and ores to reclassify different types and stages of Xiaoqinling carbonatites. It analyzes the geochemical characteristics of various carbonatite types and explores the mineralization processes of uranium and rare earth elements associated with carbonatites. [