U–Pb dating of zircons from granitoids located within the Rassokha terrane show a Silurian age of their formation. Younger dates from one of the samples are related to radiogenic lead loss during secondary alteration of the rocks. Based on REE distributions as well as well-defined positive anomalies of K and Pb and negative anomalies of Ba, Sr, Nb, Ta, and Ti, the granitoids are comparable to rocks from supra-subduction environments. Combined with intrusive ages from adjacent areas, Silurian granitoid magmatism of the Rassokha terrane supports the existence of a back-arc basin and a long island arc in Ordovician-Silurian time.

中文翻译：

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Rassokha 地块的志留纪花岗岩岩浆作用（俄罗斯东北部）

来自位于 Rassokha 地块内的花岗岩的锆石的 U-Pb 定年显示其形成的志留纪时代。其中一个样品的较年轻日期与岩石二次蚀变期间放射性铅的损失有关。根据 REE 分布以及明确定义的 K 和 Pb 的正异常以及 Ba、Sr、Nb、Ta 和 Ti 的负异常，花岗岩类与来自超俯冲环境的岩石相当。结合邻近地区的侵入时代，Rassokha 地体志留系花岗岩类岩浆作用支持奥陶纪-志留纪时期存在弧后盆地和长岛弧。