Abstract The latest Proterozoic tectonic evolution of Avalonia, one of the largest peri-Gondwanan terranes, bears on the issue of Gondwana amalgamation during the transition from Rodinia to Pangea. New paleomagnetic results from mid–late Ediacaran strata in the Newfoundland sector of Avalonia confirm substantial apparent motion of that terrane between ca. 590 and 560 Ma, consistent with a true polar wander interpretation for that interval. When the Avalonian poles are mapped onto complementary paleomagnetic records from West Africa and Laurentia, the Avalonia terrane may occupy any of four possible positions, all of which are far-removed from those cratons. Choosing the most kinematically parsimonious location leading toward Gondwana assembly, we find that Avalonia was most likely proximal to Amazonia during the Ediacaran–Cambrian transition, with a substantial (∼3000 km) separation between Amazonia and West Africa at that time. Our results thus favor the existence of a wide Clymene Ocean and subsequent Cambrian final assembly of West Gondwana, providing a key snapshot onto the evolving Rodinia-Gondwana supercontinental transition.

中文翻译：

---

阿瓦隆尼亚晚期埃迪卡拉纪古地理与西冈瓦纳寒武纪集合

摘要 Avalonia 是最大的近冈瓦纳地体之一，其元古界的最新构造演化与 Rodinia 向 Pangea 过渡期间冈瓦纳大陆并合问题有关。来自阿瓦隆尼亚纽芬兰地区中晚期埃迪卡拉纪地层的新古地磁结果证实了约 590 和 560 Ma，与该区间的真实极地漂移解释一致。当阿瓦隆极地被映射到来自西非和劳伦西亚的互补古地磁记录时，阿瓦隆地体可能占据四个可能位置中的任何一个，所有这些位置都远离这些克拉通。选择导致冈瓦纳大陆组装的运动学上最简约的位置，我们发现在埃迪卡拉纪 - 寒武纪过渡期间，阿瓦隆尼亚最有可能靠近亚马逊河，当时亚马逊河和西非之间有很大的距离（约 3000 公里）。因此，我们的结果有利于广阔的克莱门洋的存在和随后的西冈瓦纳的寒武纪最终组装，为不断发展的罗迪尼亚-冈瓦纳超大陆过渡提供了关键快照。