LAUSR

Abstract The Miyun area is located in the western margin of the Eastern Block of the North China Craton (NCC), and granulite- to amphibolite facies tectono-metamorphic events occurred in the Precambrian. In this contribution, high-resolution secondary ion mass spectrometry (SIMS) U-Pb dating of metamorphic zircon from garnet-pyroxene amphibolite yielded the metamorphic age of 2507 ± 4 Ma. SIMS U-Pb dating of monazite from garnet-biotite gneiss yielded the metamorphic ages of 2496 ± 16 Ma and 1834 ± 21 Ma, respectively. Furthermore, 40Ar/39Ar dating of hornblende from amphibolite yielded plateau ages of 1817 ± 41–1795 ± 19 Ma, and the biotite yielded a plateau age of 1744 ± 12 Ma. Combined with previous studies and the closure temperatures of the dating minerals, it is inferred that the Miyun area experienced a late Neoarchean granulite-facies metamorphic event occurred at ~2.50 Ga, followed by a late Paleoproterozoic amphibolite-facies metamorphic event occurred at ~1.83–1.74 Ga. These two tectono-metamorphic events are ascribed to the Precambrian orogenic-related environments.