Abstract—

The U–Th–Pb (LA-ICP-MS) dating of detrital zircons from the Upper Precambrian metaterrigenous rocks of the Chetlas Group in the Middle Timan Range (Svetlinskaya, Novobobrovsk, and Vizingskaya formations) enabled the reconstruction of the provenance of detrital material and establishing the maximum depositional age (MDA) of these sediments (middle–terminal Middle Riphean). It was found that the studied terrigenous rocks contain Archean–Early Proterozoic and Early and Middle Riphean zircons. The possible sources of the pre-Riphean and Early Riphean zircons could have been the rocks of the basement of the East European Craton (Baltica). The presence of a significant proportion of Middle Riphean grains among detrital zircon populations in all three formations indicates a significant role of the Sveconorwegian–Grenvillian Orogen as a source of detrital material for the sedimentary deposits of the Middle Timan. The obtained data along with the published data on the ages of detrital zircons in the Upper Precambrian rocks of the Middle Timan and some other regions at the northern and eastern (in the present-day coordinates) peripheries of Baltica suggest a much wider extent of the Sveconorwegian–Grenvillian Orogen than is deemed to be at present.

中文翻译：

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中帝曼 Chetlas 群 Riphean 岩石的年龄和成因：U-Th-Pb (LA-ICP-MS) 碎屑锆石的年代测定

摘要-

对来自中蒂曼山脉（Svetlinskaya、Novoobobrovsk 和 Vizingskaya 地层）Chetlas 群上前寒武统变生岩的碎屑锆石进行 U-Th-Pb (LA-ICP-MS) 测年能够重建碎屑材料的来源并确定这些沉积物（中河末期）的最大沉积年龄（MDA）。研究发现，所研究的陆源岩石含有太古代—早元古代和早、中里弗世锆石。前Riphean和早Riphean锆石的可能来源可能是东欧克拉通（波罗的海）基底的岩石。在所有三个地层的碎屑锆石群中都存在相当大比例的中里弗阶颗粒，这表明 Sveconorwegian-Grenvilian 造山带作为中蒂曼沉积沉积物的碎屑材​​料来源具有重要作用。获得的数据以及已发表的关于中蒂曼上前寒武纪岩石和波罗的海北部和东部（在今天的坐标中）周边的一些其他地区的碎屑锆石年龄的数据表明，在更广泛的范围内Sveconorwegian-Grenvillian 造山带比目前认为的要高。