摘要
The Tianzhushan intrusive complex is one of the Late Yanshanian intermediate-felsic complexes in the Dabie orogenic belt, which was emplaced in two stages. The amphibole quartz monzonite of the earlier stage has larger SiO2 content variation ranging from 59.83% to 70.12%, with K2O+Na2O from 7.02% to 9.56%. Sr and Nd isotope geochemical characteristics suggest that the intermediate-felsic rocks were derived from the old lower crust which is similar in chemical composition to the metamorphic assemblage in North Dabie Mountains. New LA-ICP-MS zircon U-Pb dating suggests that the crystallization age of the Tianzhushan complex is (127±1)~(131±1) Ma, in agreement with the ages (120~135 Ma) of the large-scale intrusive intermediate-felsic and mafic-ultramafic rocks in the region.