Ordovician-Silurian subduction, Early Devonian arc-contient collision and followed post-collision extension are recorded in the north of the North China Craton. Most previous research has focused on the first two processes. Discussion on the post-collisional extension and its tetonic regime is still limited. In this study, ⁴⁰Ar-³⁹Ar muscovite ages obtained from the central part of the northern North China Craton were analyzed to shed light on the timing of post-collision extension. Garnet muscovite schist and muscovite quartz schist in the Jianshan Formation yielded ⁴⁰Ar-³⁹Ar muscovite plateau ages of 412 ± 3 Ma and 391 ± 3 Ma, respectively. Two other ⁴⁰Ar-³⁹Ar muscovite plateau ages (389 ± 2 Ma and 397 ± 2Ma) were obtained for two Mesoproterozoic monzogranites intruding into the Jianshan Formation. Based on previous research, the northern North China Craton underwent a collision event with Bainaimiao arc at c. 415 Ma, followed by post-collision extension in early Late Paleozoic. Therefore, combined with the newly acquired muscovite ⁴⁰Ar-³⁹Ar dating results, the Jianshan Formation might go through regional metamorphism at c. 412 Ma during the collision process. Subsequently, the Jianshan Formation and monzogranites intruding into it went through rapid exhumation along with metamorphism at c. 397–389 Ma in a post-collision extensional setting. The muscovite ⁴⁰Ar-³⁹Ar ages provide new markers for the exhumation history and the post-collisional extension setting during Early-Late Devonian in the study area. Furthermore, slab breakoff as the cause for this extensional setting is argued by the emplacement of the Early-Late Devonian alkaline rocks.

中文翻译：

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沿华北克拉通北缘的板片折断制度引起的泥盆纪晚期碰撞后延展：白云母40Ar-39Ar约会的意义

在华北克拉通北部记录了奥陶纪-思陆纪俯冲，早期泥盆纪弧形碰撞以及随后的碰撞后伸展。以前的大多数研究都集中在前两个过程上。关于碰撞后延伸及其伸缩状态的讨论仍然有限。在这项研究中，分析了从华北克拉通北部中部获得的⁴⁰ Ar- ³⁹ Ar白云母年龄，以阐明碰撞后延伸的时间。尖山组的石榴石白云母片岩和白云母石英片岩分别产生⁴⁰ Ar- ³⁹ Ar白云母平台期，分别为412±3 Ma和391±3 Ma。另外两个⁴⁰ Ar- ³⁹两次侵入尖山组的中元古代独生花岗岩获得了Ar白云母高原年龄（389±2 Ma和397±2Ma）。根据先前的研究，华北克拉通北部与白奈庙弧在c发生了一次碰撞事件。415 Ma，后古生代晚期发生碰撞后延伸。因此，结合新获得的白云母⁴⁰ Ar- ³⁹ Ar测年结果，尖山组可能在c经历区域变质作用。在碰撞过程中为412 Ma。随后，尖山组和侵入其中的辉长花岗岩经历了快速的发掘和变质作用。397–389 Ma，处于碰撞后延伸环境中。白云母⁴⁰ Ar- ³⁹年龄为研究区早泥盆世时期的尸体发掘史和碰撞后的延伸环境提供了新的标记。此外，早泥盆世碱性岩的侵位也证明了板块破裂是这种伸展环境的原因。