Abstract It is thought that the North China Block collided with Pangea earlier than the closure of the Mianlue Ocean between the South and North China Blocks. Therefore, the closure of the Mianlue Ocean, which induced the formation of the Qinling-Dabie Orogen, led to the amalgamation of the South China Block and Pangea. Yet, the timing of closure remains poorly constrained. We present detrital zircon U-Pb ages, trace element and Hf isotopic data for an upper Permian-lower Triassic sedimentary succession in the Western Hubei Basin, northern Yangtze Block, South China. One major age population of 250–330 Ma and four minor age populations of 400–650 Ma, 1030–1300 Ma, 1600–2000 Ma and 2300–2800 Ma were identified. Trace element and Hf isotopic data indicate zircons in the major age population may have sourced from active continental margins. When integrated with tectono-magmatic events of adjacent blocks, our data support that these detrital zircons were mainly sourced from the Qinling Orogen in the southern North China Block. Combined with continental subduction-related metamorphic events in the Dabie Terrane and syn-collisional granitoids in the West Qinling Belt, as well as the paleomagnetic data, our data support that the Mianlue Ocean experienced a scissors-like closure from the Late Permian in the east to the Middle Triassic in the west. In the middle of the Qinling-Dabie Orogen, the closure of the ocean took place earlier than ~255 Ma. This study supports the hypothesis that the South China Block became a part of Pangea during the Late Permian-Middle Triassic.

中文翻译：

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华南扬子地块北部晚二叠世-早三叠世沉积序列碎屑锆石U-Pb年龄、微量元素和Hf同位素：对盘古地区重建华南地块的启示

摘要 认为华北地块与盘古大陆发生碰撞的时间早于华南地块与华北地块之间的勉略海闭合。因此，绵略海的闭合导致了秦岭-大别造山带的形成，导致了华南地块和盘古大陆的合并。然而，关闭的时间仍然很有限。我们提供了华南扬子地块北部湖北盆地上二叠统-下三叠统沉积序列的碎屑锆石 U-Pb 年龄、微量元素和 Hf 同位素数据。确定了 1 个 250-330 Ma 的主要年龄人口和四个 400-650 Ma、1030-1300 Ma、1600-2000 Ma 和 2300-2800 Ma 的次要年龄人口。微量元素和 Hf 同位素数据表明主要年龄人群中的锆石可能来自活动大陆边缘。结合相邻块体的构造岩浆事件，我们的数据支持这些碎屑锆石主要来自华北地块南部的秦岭造山带。结合大别地块大陆俯冲相关变质事件和西秦岭带同碰撞花岗岩，以及古地磁资料，我们的数据支持棉略海在东部晚二叠世经历了剪刀状闭合到西部的中三叠世。秦岭-大别造山带中段闭海时间早于~255 Ma。这项研究支持了华南地块在晚二叠世-中三叠世成为盘古大陆一部分的假设。我们的数据支持这些碎屑锆石主要来自华北地块南部的秦岭造山带。结合大别地块大陆俯冲相关变质事件和西秦岭带同碰撞花岗岩，以及古地磁资料，我们的数据支持棉略海在东部晚二叠世经历了剪刀状闭合到西部的中三叠世。秦岭-大别造山带中段闭海时间早于~255 Ma。这项研究支持了华南地块在晚二叠世-中三叠世成为盘古大陆一部分的假设。我们的数据支持这些碎屑锆石主要来自华北地块南部的秦岭造山带。结合大别地块大陆俯冲相关变质事件和西秦岭带同碰撞花岗岩，以及古地磁资料，我们的数据支持棉略海在东部晚二叠世经历了剪刀状闭合到西部的中三叠世。秦岭-大别造山带中段闭海时间早于~255 Ma。这项研究支持了华南地块在晚二叠世-中三叠世成为盘古大陆一部分的假设。结合大别地块大陆俯冲相关变质事件和西秦岭带同碰撞花岗岩，以及古地磁资料，我们的数据支持棉略海在东部晚二叠世经历了剪刀状闭合到西部的中三叠世。秦岭-大别造山带中段闭海时间早于~255 Ma。这项研究支持了华南地块在晚二叠世-中三叠世成为盘古大陆一部分的假设。结合大别地块大陆俯冲相关变质事件和西秦岭带同碰撞花岗岩，以及古地磁资料，我们的数据支持棉略海在东部晚二叠世经历了剪刀状闭合到西部的中三叠世。秦岭-大别造山带中段闭海时间早于~255 Ma。这项研究支持了华南地块在晚二叠世-中三叠世成为盘古大陆一部分的假设。