Abstract This study presents the first zircon U-Pb LA-MC-ICP-MS ages and whole-rock Rb/Sr and Sm/Nd data from exotic blocks (Bugaj and Andrychów) from the Western Outer Carpathians (WOC) flysch. The CL images of the zircon crystals from both samples reveal typical magmatic textures characterized by a well-defined concentric and oscillatory growth zoning. A concordia age 580.1 ± 6.0 Ma of the zircons from the Bugaj sample is considered to represent the crystallization age of this granite. The zircon crystals from the Andrychów orthogneiss yield an age of 542 ± 21 Ma, interpreted as the uppermost Proterozoic, magmatic crystallization age of the granitoid protholith. The initial (at ca. 580 Ma) 87Sr/86Sr ratios of the Bugaj granitoids (0.72997 and 0.72874) are highly radiogenic, pointing to the assimilation of an older, possibly strongly Rb enriched source to the Bugaj melt. The Nd isotope systematics (εNd580 –1.4 and 0.4) also point to a significant contribution of such a distinct mantle source. On the basis of the sequence of magmatic events obtained from U-Pb zircon ages, we suggest that exotic mega blocks deposited to the WOC basins were related to the Brunovistulicum Terrane. They belong to the group of Vendian/Cambrian granitoids representing the latest, posttectonic expression of the Cadomian cycle.

中文翻译：

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来自 Bugaj 和 Andrychów（西外喀尔巴阡山脉，波兰）的奇异巨型块体的 Cadomian 原岩年龄及其古地理意义

摘要 本研究展示了来自西外喀尔巴阡山脉 (WOC) 复理石的奇异区块（Bugaj 和 Andrychów）的第一个锆石 U-Pb LA-MC-ICP-MS 年龄和全岩 Rb/Sr 和 Sm/Nd 数据。来自两个样品的锆石晶体的 CL 图像揭示了典型的岩浆结构，其特征是明确的同心和振荡生长分区。Bugaj 样品中锆石的协和年龄 580.1 ± 6.0 Ma 被认为代表了这种花岗岩的结晶年龄。来自 Andrychów 正方麻岩的锆石晶体的年龄为 542 ± 21 Ma，被解释为花岗岩类原岩的最上元古代、岩浆结晶年龄。Bugaj 花岗岩的初始（约 580 Ma）87Sr/86Sr 比率（0.72997 和 0.72874）具有高度放射成因，表明同化了更古老的、可能是 Bugaj 熔体的 Rb 富集源。Nd 同位素系统学（εNd580 –1.4 和 0.4）也指出了这种独特的地幔源的重要贡献。根据从 U-Pb 锆石年龄获得的岩浆事件序列，我们认为沉积到 WOC 盆地的奇异巨型块体与 Brunovistulicum Terrane 相关。它们属于代表 Cadomian 旋回的最新构造后表现形式的 Vendian/Cambrian 花岗岩类。