Constraints on uranium mineralization by chronology and microgeochemical characteristics of monazite in the Datian area of the Kangdian region, China

Abstract

Monazite, a common U-containing ore-rich mineral found in association with U minerals, has excellent sealing properties after its formation, making it a promising tool for determining the age and genetic type of U mineralization. The Datian area in the Kangdian region of China is an important Neoproterozoic U ore-forming region. It has garnered the attention of researchers owing to the presence of megacrystalline uraninite with well-developed crystal forms. However, most studies conducted on U mineralization in the Datian area have focused on macroscopic observations and uraninite, with limited reports on accessory minerals. In this study, LA-ICP-MS U-Pb chronology and in-situ major and trace element analyses were performed on monazite associated with megacrystalline uraninite in the Datian area metallogenic belt I. The research yielded the following insights: 1) U mineralization in the Datian area was estimated to have occurred approximately 770 million years ago. This age demonstrates a potential correlation with the assembly and fracturing of the Rodinia supercontinent, suggesting a geodynamic context for the mineralization event. 2) The geochemical characteristics of the monazite indicate an igneous rock origin for its genetic type. Combined with previous research findings, it is postulated that U mineralization in the Datian area may be closely linked to the partial melting of deep crustal materials within a metamorphic environment characterized by high temperature and low pressure.