Abstract—

The U–Pb dating and Hf isotope systematics of detrital zircons from a sandstone interbed in the section of the upper conglomerate sequence of the Mt. Southern Demerdzhi were carried out. The dominant populations of detrital zircons in the studied sample characterize episodes of magmatic activity within the source of the Upper Jurassic conglomerates. Magmatism was manifested in the Vendian-Cambrian, Carbon-Triassic, and Late Jurassic. The ε_Hf values of detrital zircons of these ages indicate the insignificant role of the ancient (Archean–Early Proterozoic) continental crust in the protolith of magmatic chambers. The similarity of the detrital zircons age distribution from the Middle Jurassic and Upper Jurassic conglomerate strata suggests that they are molasses of the Cimmerian orogen. The absence of products of Middle Jurassic magmatism in molasses of the Cimmerian orogen, which we fixed, limits position of the Cimmerian orogen in the southern part of the Scythian plate. It is shown that the primary source of the Precambrian detrital zircons were mobilized within the Cimmerian orogen the crustal fragments of the Peri-Gondwanan origin, rather than the basement complexes of the East European Platform, similar to the complexes of the Ukrainian shield. The reconstruction of the main stages of the accumulation of the coarse-grained strata of the Mountaineous Crimea in the context of the tectonic evolution of the southern margin of Laurasia during the Mesozoic is presented.

中文翻译：

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碎屑锆石的年龄，Hf同位素系统学和Mounatinous克里米亚南部Demerdzhi山的砾岩来源

摘要—

来自山顶砾岩层段的砂岩中碎屑锆石的U–Pb定年和Hf同位素系统。南部的Demerdzhi进行了。在研究的样本中，碎屑锆石的主要种群表征了上侏罗统砾岩源内的岩浆活动事件。岩浆岩表现在Vendian-寒武纪，碳三叠纪和晚侏罗世。该ε_铪这些年龄的碎屑锆石的值表明，古代（Archean –早元古代）大陆壳在岩浆室的原生质中的作用微不足道。中侏罗纪和上侏罗统砾岩层碎屑锆石年龄分布的相似性表明它们是西密尔造山带的糖蜜。我们已修复的Cimmerian造山带的糖蜜中没有侏罗纪岩浆作用的产物，这限制了Cimmerian造山带在Scythian板块南部的位置。结果表明，前寒武纪碎屑锆石的主要来源是在西密尔造山带内动员了Peri-Gondwanan起源的地壳碎片，而不是东欧平台的基底复合物，类似于乌克兰盾构的复合物。