A combined paleomagnetic and geochronological study was conducted on the red beds of the Zhesi Formation (ZSF) in the Xilinhot–Songliao Block (XSB) and the andesites and sandstones of the Qingfengshan Formation (QFF) in the North China Block (NCB). The ZSF tuffs and the QFF andesites were dated to 265.3 ± 1.8 Ma and 254.8–257.1 Ma, respectively, using the zircon U–Pb laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) method. A total of 246 paleomagnetic samples were subjected to stepwise thermal demagnetization. After removal of the low‐temperature viscous components acquired in the recent geomagnetic field, stable high‐temperature components (HTCs) were isolated from most samples. The HTC of the ZSF passed a fold test, and the HTC of the QFF passed both fold and reversal tests, indicating their primary origins. The corresponding paleomagnetic poles are 57.4°N/342.0°E (A ₉₅ = 4.3°) for the XSB at ~265 Ma and 54.3°N/20.2°E (A ₉₅ = 3.3°) for the NCB at ~255 Ma. Comparison of high‐quality Permian paleomagnetic poles of the XSB and NCB reveals a latitudinal convergence and relative rotation between them that led to a scissors‐like closure of the Solonker Ocean from west to east between ~265 and ~246 Ma, which controlled the mixing of the Cathaysian and Angara floras in space and time. The XSB and NCB moved rapidly northward between ~265 and ~255 Ma, which probably accelerated the end‐Guadalupian mass extinction in East Asia.

中文翻译：

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内蒙古新二叠纪晚古地磁和年代学结果及其古地理意义

在锡林浩特—松辽区块（XSB）的浙西组（ZSF）和华北区块（NCB）的青风山组（QFF）的安山岩和砂岩中，古地磁和年代学研究相结合。使用锆石U–Pb激光消融电感耦合等离子体质谱法（LA–ICP–MS），ZSF凝灰岩和QFF安山岩的日期分别为265.3±1.8 Ma和254.8–257.1 Ma。总共246个古磁性样品进行了逐步热退磁。除去最近地磁场中获得的低温粘性成分后，从大多数样品中分离出稳定的高温成分（HTC）。ZSF的HTC通过了折叠测试，而QFF的HTC通过了折叠测试和反向测试，这表明它们的主要来源。甲₉₅  = 4.3°）为XSB在〜265 Ma和54.3°N / 20.2°E（甲₉₅  = 3.3°）为NCB在〜255毫安。XSB和NCB的优质二叠纪古磁极的比较显示，它们之间存在纬向辐合和相对旋转，从而导致Solonker海洋从西向东呈剪刀状封闭，从〜265至〜246 Ma，控制了混合时空的Cathaysian和Angara植物区系。XSB和NCB在〜265和〜255 Ma之间迅速向北移动，这可能加速了东亚瓜达卢普期末的灭绝。