Abstract The Wutai Complex lies in the middle part of the Trans-North China Orogen, mainly consisting of metamorphosed volcanic-sedimentary rocks (named as “Wutai Group”) and Late Archean TTG gneisses. Garnet biotite schist from the northeastern part of the Wutai Group (lower Shizui Subgroup) mainly consists of garnet porphyroblast plus biotite, staurolite, kyanite, sillimanite / fibrolite, plagioclase, quartz as well as accessory minerals including ilmenite, magnetite, hematite, apatite, monazite and zircon. Petrographic observation and mineral chemistry indicate that these metapelites underwent the sequential prograde (M1), peak (M2) and retrograde (M3) metamorphic stages. Geothermobarometry computation and phase equilibrium modelling show that the representative samples record clockwise P-T paths passing from 3–7 kbar / 570–630 ℃ (M1) through 9–10 kbar / 615–660 ℃ (M2P) to 6–9 kbar / 655–680 ℃ (M2T) and finally to a speculated exhumation stage (M3), indicative of orogenic metamorphism. SRHIMP and LA-ICP-MS U-Pb dating on inherited detrital zircons yielded three age peaks of ∼ 2.7 Ga, ∼ 2.5 Ga and ∼ 2.1 Ga. The youngest 207Pb/206Pb age of 2064 ± 21 Ma of detrital zircon possibly constrains the maximum depositional age of the Shizui Subgroup. SIMS and SHRIMP U-Pb dating of metamorphic monazite and zircon constrain the metamorphic age of the garnet-bearing mica schist to be 1853–1823 Ma. Combined with previous data, the Wutai Complex was demonstrated to have been involved in a prolonged subduction-collision process (1.97–1.82 Ga) between the Western and Eastern Blocks in the Paleoproterozoic.

中文翻译：

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五台杂岩东北部变泥岩变质演化及U-Pb年代学：对华北造山带古元古代构造演化的意义

摘要 五台杂岩位于横贯华北造山带的中部，主要由变质火山沉积岩（简称“五台群”）和晚太古代TTG片麻岩组成。五台群东北部（下石嘴亚群）石榴石黑云母片岩主要由石榴石斑状体加黑云母、星柱石、蓝晶石、硅线石/纤纤石、斜长石、石英以及钛铁矿、磁铁矿、赤铁矿、磷灰石、独居石等副矿物组成和锆石。岩石学观察和矿物化学表明这些变泥质岩经历了连续的前行（M1）、高峰（M2）和逆行（M3）变质阶段。地热气压计计算和相平衡模型表明，代表性样品记录了从 3-7 kbar / 570-630 ℃ (M1) 到 9-10 kbar / 615-660 ℃ (M2P) 到 6-9 kbar / 655-的顺时针 PT 路径680 ℃ (M2T) 并最终达到推测的折返阶段 (M3)，表明造山变质作用。SRHIMP 和 LA-ICP-MS U-Pb 对继承碎屑锆石的定年产生了 ~2.7 Ga、~2.5 Ga 和 ~2.1 Ga 的三个年龄峰。最年轻的 207Pb/206Pb 年龄为 2064 ± 21 Ma 的碎屑锆石可能限制了最大石嘴亚群的沉积时代。变质独居石和锆石的 SIMS 和 SHRIMP U-Pb 定年将含石榴石的云母片岩的变质年龄限制在 1853-1823 Ma。结合之前的数据，