Abstract The Taihua Complex is exposed in the southern North China Craton (NCC), it has experienced a long and complicated history of multiple crustal growth, magmatism, metamorphism and deformation during the early Precambrian. Abundant leucosomes are widely distributed within the migmatites of the Taihua Complex, which occurred as irregular lenses, blocks, layers or dikes with several thickness of millimeters to tens of centimeters wide. Meanwhile, former presence of melt and typical microstructures related to partial melting also can be recognized in the thin sections under the microscope, those provide compelling evidences that the Taihua Complex was extensively suffered partial melting, and can be regarded as the best target to decipher multistage anatexis during metamorphism as well as assembly of the whole NCC. However, the timing and nature of the partial melting in the Taihua Complex have not been well studied up to now. In this contribution, we present an integrated in situ zircon U-Pb ages and Hf isotope compositions for the Paleoproterozoic migmatites from the Taihua Complex in the southern NCC. Both the metasedimentary and metamorphized plutonic rocks of the Taihua Complex have extensively suffered partial melting. The ca. 2.50 Ga magmatic zircons or inherited magmatic cores from the migmatites and leucosomes present similar Hf isotope composition to those of the contemporaneous depleted mantle at ca. 2.50 Ga, suggesting that ca. 2.50 Ga is a major period of crustal growth in the southern NCC as well as the whole NCC. The ages of metamorphic zircon obtained from leucosomes, melanosomes and migmatites show a large time interval of 1909-1798 Ma, indicating that the Taihua Complex has experienced a persistence of partial melting event during Late Paleoproterozoic that lasted more than 100 Ma. The crustal anatexis in the southern NCC probably occurred during the post-peak upper amphibolite- to granulite facies retrograde stage with a migmatization temperature of at least 652–753°C. The decompression melting and widespread migmatization of the Taihua Compelx are probably due to extension related to exhumation of the previously thickened crust during Paleoproterozoic collision between the Eastern and Western block or between the Southern Archean Block with other micro-continent. The main collision-related assembly and crustal thickening events in the southern NCC likely occurred at ca. 1.95 Ga, rather than ca. 1.85 Ga as previously believed.

中文翻译：

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华北克拉通南部部分熔融的持续性：来自太华杂岩古元古代混合岩的证据

摘要 太华杂岩出露于华北克拉通南部，在早前寒武纪经历了漫长而复杂的多次地壳生长、岩浆作用、变质作用和变形的历史。太华杂岩混杂岩内广泛分布着丰富的白质体，呈不规则透镜状、块状、层状或堤状，厚度为数毫米至数十厘米宽。同时，在显微镜下的薄片中也可以识别出熔体的存在和与部分熔融有关的典型微观结构，这些为太华杂岩体广泛遭受部分熔融提供了有力的证据，可作为破译多阶段的最佳目标。在变质过程中以及整个 NCC 的组装过程中都发生了厌氧反应。然而，迄今为止，对太华杂岩体部分熔融的时间和性质尚未得到很好的研究。在这个贡献中，我们提出了一个完整的原位锆石 U-Pb 年龄和 Hf 同位素组成，用于来自华北克拉通南部太华杂岩体的古元古代混合岩。太华杂岩的变沉积岩和变质深成岩都发生了广泛的部分熔融。约。来自混合岩和隐色体的 2.50 Ga 岩浆锆石或继承的岩浆核呈现出与约 10 年代同时期贫化地幔的 Hf 同位素组成相似的 Hf 同位素组成。2.50 Ga，表明约。2.50 Ga 是华北克拉通南部乃至整个华北克拉通地壳生长的主要时期。从白体、黑素体和混合岩中获得的变质锆石的年龄显示出较大的时间间隔，为 1909-1798 Ma，表明太华杂岩在晚古元古代经历了持续超过 100 Ma 的部分熔融事件。华北克拉通南部的地壳深熔可能发生在峰后上部角闪岩-麻粒岩相逆行阶段，混杂温度至少为652-753°C。太华岩层的减压熔融和广泛的混合作用可能是由于东、西地块或南太古代地块与其他微大陆之间的古元古代碰撞过程中先前加厚的地壳的剥露有关。NCC 南部的主要碰撞相关组装和地壳增厚事件可能发生在大约 1.95 Ga，而不是ca。之前认为的 1.85 Ga。