Abstract

The paper presents the results of U-Pb and Lu-Hf isotope studies of detrital zircons from the terrigenous the Lan 410 Ma (Lower Devonian), Terrane in the eastern part of the Mongol-Okhotsk fold belt. The lower age rocks limits are for the Nivakh formation ~ for the Verkholan series ~332 Ma (Mississippian), for the Ugokhan series ~239 Ma (Middle Triassic). The evidences were obtained for the Lower Triassic (or Middle-Late Triassic) age of the sediments assigned to the Ugokhan series previously classified as Upper Paleozoic. These data indicate that the Lower Mesozoic sedimentary complexes in the structure of this belt are developed much wider than is currently believed. The main sources of clastic material for the Devonian, Carboniferous, and Triassic sedimentary rocks of the Lan terrane were mainly igneous and metamorphic complexes of the North Asian craton framing, along with island arcs. The Lan Terrane can be considered as a fragment of the accretionary complex formed in front of the southeastern margin of the North Asian craton.

中文翻译：

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蒙古-鄂霍次克褶皱带兰地层沉积岩的年龄和来源：锆石U-Pb和Lu-Hf同位素研究的结果

摘要

本文介绍了蒙古-鄂霍次克褶皱带东部陆源陆源Lan 410 Ma（下泥盆纪）碎屑锆石的U-Pb和Lu-Hf同位素研究结果。较低年龄的岩石界限为Nivakh组〜Verkholan系列〜332 Ma（密西西比山脉），Ugokhan系列〜239 Ma（中三叠纪）。获得了属于先前被归类为上古生界的Ugokhan系列的沉积物的下三叠世（或中晚三叠世）时代的证据。这些数据表明，该带结构中的下中生界沉积复合物比目前认为的要宽得多。泥盆纪，石炭纪，Lan地层的三叠纪和三叠纪沉积岩主要是北亚克拉通框架的火成岩和变质复合体，以及岛弧。Lan Terrane可被视为北亚克拉通东南缘前方形成的增生复合物的一部分。