Constructing the Cretaceous Highly Silicic Plutons in SE China through the Magmatic Plumbing System.

This article focuses on the magmatic evolution and formation processes of high-silica plutons in southeastern China, specifically the Jiuzhen batholith and Yunhe pluton. Through integrated analyses of bulk-rock geochemistry, zircon U–Pb ages, hafnium (Hf) isotopes, and trace elements across vertical cross sections, the study reveals that both plutons originated from middle- to upper-crustal magma reservoirs involving crystal-melt segregation. The Jiuzhen batholith formed via rejuvenation of a water-rich magma reservoir by mantle-derived mafic magma, followed by in situ differentiation and melt extraction at depths of ~1.5–4.5 km, while the Yunhe pluton developed from a high-temperature, water-poor magma reservoir formed by mixing felsic melts from ancient crust and mantle-derived mafic magmas, with vertical compositional variations driven by upward migration of residual melts. The findings emphasize that, beyond deep crystal-melt segregation, in situ crystal-melt segregation within shallow crustal magma reservoirs significantly influences the compositional and textural evolution of high-silica granitic plutons in this region.