Abstract—

Detrital zircons of Ordovician terrigenous sequences are studied in various Southern Uralian tectonic units. The age of detrital zircons of the West Uralian and Transuralian megazones, Taganai–Beloretsk Zone, and Kraka allochthons spans from the Late Archean to the end of the Vendian– beginning of the Cambrian; Early Precambrian and Early–Middle Riphean zircons are the most abundant. Vendian–Cambrian detrital zircons are strongly dominant in the Uraltau Zone, Sakmara allochthons, and East Uralian Megazone; the zircons of other ages are absent or extremely rare. The Vendian–Cambrian detrital zircons of all Southern Urals zones probably derive from volcanic and granitic rocks of the marginal continental belt, which are part of the Uraltau Zone, Sakmara allochthons, and East Uralian Megazone. The Lu–Hf isotopic characteristics of Vendian–Cambrian detrital zircons indicate that their parental rocks formed on a heterogeneous basement that includes blocks of juvenile and ancient continental crust. According to a model of the pre-Ordovician tectonic evolution of the Southern Urals, at the end of the Late Riphean, the passive margin of the East European Platform collided with a block on a heterogeneous basement. The formation of the block terminated with the Grenville Orogeny. After collision, a volcano-plutonic belt originated in the Vendian–Cambrian at the actively evolved margin of the East European Platform.

中文翻译：

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乌拉尔南部的文迪-寒武纪活动大陆边缘的重建：从奥陶纪陆生岩石中研究碎屑锆石的结果

摘要—

在南乌拉尔构造单元中研究了奥陶纪陆源层序的碎屑锆石。西乌拉尔和Transuralian巨型带，Taganai–Beloretsk带和Kraka异体的碎屑锆石的年龄从太古宙晚期到Vandian末期-寒武纪开始。早前寒武纪和早中期的里菲安锆石最为丰富。Vendian-Cambrian碎屑锆石在Uraltau地带，Sakmara异源地带和East Uralian巨型地带中占主导地位。其他年龄的锆石不存在或极为罕见。所有南部乌拉尔地区的Vendian-Cambrian碎屑锆石可能来自边缘大陆带的火山岩和花岗岩岩，它们是Uraltau地带，Sakmara异位子和东乌拉尔大地带的一部分。Vendian-Cambrian碎屑锆石的Lu-Hf同位素特征表明，它们的母岩形成于一个非均质基底上，该基底包括未成年块体和古代大陆壳。根据南乌拉尔奥陶纪前构造演化的模型，在里菲安晚期，东欧平台的被动边缘与异质基底上的一个块相撞。格伦维尔造山运动终止了该块的形成。碰撞后，一个火山-火山成岩带起源于在东欧平台活跃演化的边缘的文迪安-寒武纪。在里菲安晚期，东欧平台的被动边缘与异质地下室的一个块相撞。格伦维尔造山运动终止了该块的形成。碰撞后，一个火山—火山成岩带起源于Ventian-Cambrian，处于东欧平台活跃演化的边缘。在里菲安晚期，东欧平台的被动边缘与异质地下室的一个块相撞。格伦维尔造山运动终止了该块的形成。碰撞后，一个火山—火山成岩带起源于Ventian-Cambrian，处于东欧平台活跃演化的边缘。