Late Cretaceous adakitic and A-type granitoids in Chanang, southern Tibet: Implications for Neo-Tethyan slab rollback

The co-existence of Cretaceous adakitic and A-type granitoids in southern Tibet can offer fundamental constraints on subduction the Neo-Tethyan oceanic plate associated crustal growth processes, if their petrogenetic relationships are understood. Here, we report whole-rock geochemistry, zircon U-Pb geochronology, situ Hf isotopes trace elements from Chanang intrusive suite, including Zeyu Cuojielin plutons. pluton is composed quartz syenites with high K2O + Na2O, FeOT, Zr contents distinct negative Eu anomalies, consistent fractional crystallization mafic magma a reducing, low-pressure, high-temperature environment. pluton, by contrast, has strikingly density enclaves. elemental isotopic signatures enclaves indicate hybrid origin mixing magmas derived mantle wedge juvenile lower crust. host rocks, low MgO, Cr, Ni contents, show typical characteristics which originate residual or fractionated amphibole aluminous A2-type granites rocks indicates an anomalous relatively H2O-rich synchronous regional occurrence calc-alkaline magmatism, charnockites, granulite-facies metamorphism, back-arc extension, generation two studied types best be explained context episode rollback slab late Cretaceous.