This paper is the result of mineral exploration engineering.

Objective The South Qinling Orogen (SQL)hosts a large-scale Early Paleozoic alkaline magmatic rock belt, characterized by diverse lithological-lithofacies assemblages and associated with igneous carbonatites. Several large to superlarge alkaline rock-carbonatite-type niobium (tantalum)-rare earth deposits have been explored in this region, making it a natural laboratory for studying mantle enrichment processes, cross-sphere material cycling (e.g., deep carbon cycling) within the Earth system, and the enrichment mechanisms of critical metals. However, the characteristics of the rock assemblages and the spatiotemporal distribution patterns of Early Paleozoic alkaline rocks and carbonatites in the SQL remain one of the fundamental geological issues to be addressed in theoretical research on petrogenesis and mineralization, as well as in the mineral exploration in this area.

Methods This paper systematically compiles and synthesizes petrological, geochronological, and geochemical data of Early Paleozoic alkaline rocks and carbonatites in the SQL, with a focus on analyzing their spatiotemporal distribution characteristics.

Results It is proposed that the Early Paleozoic alkaline magmatism in SQL primarily intruded or extruded along the Ankang-Zhushan fault and the Hongchunba-Zengjiaba fault zone, as well as their associated rift basins. The alkaline magmatic activities predominantly occurred between 430~480 Ma, spanning from the Early Ordovician to the Early Silurian. During this period, the intensity of alkaline magmatism gradually increased, with its activity centers migrating eastward, accompanied by an increasing degree of magmatic evolution. In the late (or main) stage (~440 Ma), the alkaline rock assemblages were primarily composed of highly evolved trachytic rocks, locally associated with carbonatites, which facilitated the enrichment and mineralization of niobium (tantalum) and rare earth elements.

Conclusions The upwelling of the asthenosphere and the resulting deep tensile faulting provide favorable tectonic conditions for the formation, evolution, and emplacement of alkaline rock-carbonatite magmas, which are also key controlling factors for the formation of Nb (Ta)–REE deposits associated with alkaline rocks and carbonatites. Since the Mesozoic, multi-phase tectonic events during the Middle Triassic, Late Triassic–Middle Jurassic, and Late Jurassic–Late Cretaceous have progressively reshaped the distribution patterns of alkaline rocks. Associated hydrothermal activity subsequently promoted the local enrichment and mineralization of rare earth elements and tantalum.