Generation of leucogranites via fractional crystallization: A case study of the Jurassic Bengbu Granite in the southeastern North China Craton

Abstract The magmatic processes that form leucogranites are closely related to plate collision. As the products of crustal anatexis, leucogranites provide clues to intracrustal differentiation and the regional tectonic evolution. The Bengbu area is located along the southeastern margin of the North China Craton (NCC), 150 km north of the Dabie Orogen, and is bounded by the Tancheng–Lujiang Fault Zone to the east. Late Jurassic leucogranites are widely distributed in the Bengbu area. We collected samples of the Bengbu leucogranite (BLG) and analyzed data on whole-rock geochemistry, zircon U–Pb geochronology, zircon in situ Lu–Hf isotopes, quartz in situ O isotopes, and total bulk Sr–Nd–Pb isotopes. Zircon U–Pb dating yielded formation ages for these leucogranites of ∼160 Ma. The samples are characterized by high SiO2 (72.4 wt.%−76.9 wt.%), alkali (7.3 wt.%−9.4 wt.%), and Al2O3 (13.4 wt.%−15.5 wt.%) contents. In addition to two samples exhibiting the rare-earth element tetrad effect, all rocks have high differentiation index values (95–99), extremely low iron–magnesium–titanium oxide contents (total Fe2O3