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.

中文翻译：

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华北克拉通密云地区晚新太古代和晚古元古代构造变质事件的年代学新证据

摘要 密云地区位于华北克拉通东地块西缘，前寒武纪发生麻粒岩-角闪岩相构造变质事件。在这项贡献中，来自石榴石-辉石角闪石的变质锆石的高分辨率二次离子质谱 (SIMS) U-Pb 定年产生了 2507 ± 4 Ma 的变质年龄。石榴石-黑云母片麻岩中独居石的 SIMS U-Pb 测年结果分别为 2496 ± 16 Ma 和 1834 ± 21 Ma。此外，角闪石角闪石的 40Ar/39Ar 测年得出的高原年龄为 1817 ± 41–1795 ± 19 Ma，黑云母得出的高原年龄为 1744 ± 12 Ma。结合以往的研究和测年矿物的闭合温度，