板块内部酸性火山作用与潜在金-铀矿化的关系OACHSSCD

Calderas are giant volcanic structures formed by the collapse of a crustal ring following the large-scale evacuation of magma chambers,representing the most intense stage of volcanic activity.Traditional volcanology holds that large felsic calderas mainly form at subduction zones,volcanic arcs,and mid-ocean ridges.Within continental plates,stable lithosphere and weak magmatism hinder the development of large felsic magma systems and high-intensity eruptions.In recent years,the large circular structure in Duolun,Inner Mongolia,has been confirmed as an Early Cretaceous large intraplate felsic caldera.It exhibits a complete sequence of eruption-collapse-resurgence-hydrothermal mineralization,with an eruption intensity of VEI ≈6,comparable to that of the Valles caldera in the United States.It shows metallogenic potential for strategic minerals such as gold and uranium.Based on recent progress in domestic and international volcanic research and the author's recent achievements,this paper systematically reviews caldera concepts,the Volcanic Explosivity Index(VEI),and the distribution of typical global calderas.It discusses the identification criteria,magmatic genesis,evolutionary sequence,deep geodynamic mechanisms,and metallogenic system characteristics of large intraplate felsic calderas,based on morphology,lithology,structure,geochronology,geochemistry,geophysics,and global comparisons.The results indicate that the Duolun volcanic structure is a large intraplate felsic caldera with a VEI≈6,formed under the combined control of lithospheric delamination and deep-mantle plume activity along the northern margin of the North China Craton.The felsic magma has high gold-uranium background values and is associated with large-scale hydrothermal activity,providing favorable geological conditions for the formation of large gold and uranium deposits.This study enriches the theory of intraplate volcanic dynamics and provides new insights for strategic mineral exploration in the Mesozoic volcanic terranes of northern China.