Origin and tectonic implications of Early Cretaceous high- and low-Mg series rocks and mafic enclaves in the Bomi–Chayu Fold Belt, SE Tibet

Early Cretaceous granitoids are widespread on the Tibetan Plateau and record the tectonic evolution of several Tethyan oceans. We describe Early Cretaceous high-Mg (Mg# > 50) and low-Mg (Mg# < 50) granitoids, minor diorites, and mafic enclaves from the Bomi–Chayu Fold Belt, SE Tibet. Zircon U-Pb dating reveals two episodes of granitoid emplacement at ~122 and ~117 Ma. High-Mg series rocks have higher Mg# and compatible element concentrations...