Mantle magmatism in the Tarim large igneous province and southwestern Central Asian Orogenic Belt triggered by deeply subducted slabs

The genetic relationship between the Tarim mantle plume – associated with the Tarim Large Igneous Province (TLIP) and synchronous mantle magmatism in the southwestern Central Asian Orogenic Belt (CAOB) – and early Palaeozoic subduction of the southern Palaeo-Asian Ocean (SPAO) remains debated. Integration of Sr–Nd isotopic data from the TLIP and southwestern CAOB reveals distinct mantle components. Coupled light Mg and heavy Zn isotopes identify one component as recycled early Palaeozoic carbonated materials. By compiling Sr–Nd isotopes from early Palaeozoic arc magmatic rocks and applying isotopic mixing models, we trace these carbonate materials to Ordovician–Silurian subducted slabs during SPAO closure. Geochemical evidence (FCKANTMS parameters, Zn/Fe ratios, high-Ni/low-Ca olivine compositions) and partial melting models indicate significant pyroxenite contributions (12–60 wt%) in early Permian magmatism. This pyroxenite links surface magmatism to deep recycled slabs. We propose that the Tarim plume is a thermochemical mantle plume fuelled by these subduction-derived materials, directly connecting Permian mantle dynamics to early Palaeozoic SPAO closure.