Cenozoic intraplate volcanism in central Asia: Mantle upwelling induced by India-Eurasia collision

Most of Earth’s volcanism occurs at tectonic plate boundaries associated with subduction or rifting processes. The mantle plume hypothesis is an important supplement to tectonics for explaining some high-volume intraplate volcanic fields. However, many magmatic provinces occur as low-volume, monogenetic basaltic-suite fields that are neither plate-boundary processes nor attributable plumes, and the origin such magmatism has long been debated. Identification their source characteristics possible mechanisms trigger melting will provide essential insights into heterogeneity also develop our knowledge movement through time. Here, we report new geochronology, mineral chemistry (especially olivine), whole-rock chemical Sr-Nd-Pb-Hf isotopic compositions on Cenozoic intracontinental alkaline basalts from northwestern Tarim craton (central Asia), aiming better assess low-volume effusive (ca. 42 Ma) have olivine (e.g., mean Ni abundances ∼2250 ppm, Mn/Zn ratios 13.7) consistent derivation a mixed peridotite-pyroxenite source. Moderately depleted isotopes (87Sr/86Sr = 0.7039−0.7053; εNd +4.0 +5.5; 206Pb/204Pb 18.247−18.535; εHf +8.1 +8.7) require young 500 oceanic crust recycled source, possibly related events during assembly Pangea. Estimated thermal-chemical conditions indicate original occurred in relatively dry (H2O 1.4 ± 0.9 wt%) reduced (logfO2 ΔFMQ −0.97 0.21, where FMQ fayalite-magnetite-quartz) asthenosphere under potential temperature ∼1420 °C pressure ∼3.7 GPa (corresponding depth ∼120 km). Combining these data regional history geophysical (high-resolution P-wave tomography), propose long-lasting India-Eurasia collision triggered asthenospheric upwelling, focusing melts along translithospheric zones weakness; this model provides robust explanation observed central Asia. integrated geochemical evidence reveals subduction−induced upwelling represents likely mechanism generation regions plume-absent within continents.