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Sources of the Paleoproterozoic Terrigenous Rocks of the Nizhnekhani Graben-Syncline, Western Part of the Aldan Shield, According to the U–Th–Pb (LA-ICP-MS) Geochronological and Nd Isotopic Studies: To the Question of Correlation of the Udokan Complex Deposits

The results of U–Th–Pb (LA-ICP-MS) geochronological studies of detrital zircon and Sm–Nd isotopic studies of metaterrigenous rocks of the Udokan Complex of the Nizhnekhani graben-syncline in the western part of the Aldan Shield are discussed. On the basis of the data obtained, it was found that the accumulation of terrigenous deposits of the Nizhnekhani graben-syncline occurred after 2.65 and up to 1.9 Ga, probably at the Paleoproterozoic stage of the development of the region. The igneous and metamorphic rocks formed at ca. 2.65, 2.71, 2.82–2.86, 2.99, 3.10–3.21, and probably 3.26–3.42 Ga within the Chara–Olekma Geoblock, its junction zone with the West Aldan Megablock, and the Kurulta Block of the Stanovoi suture zone were the sources of detrital material. Metaterrigenous rocks of the Nizhnekhani graben-syncline were formed from crustal sources with the Paleo- and Mesoarchean Nd model ages, while a significant contribution of the Paleoproterozoic juvenile material was established for the metasedimentary rocks of the Kodar–Udokan Trough. Significant differences in the age and Nd isotopic characteristics of sources of terrigenous deposit of the Nizhnekhani graben-syncline and the Kodar–Udokan Trough suggest that they accumulated in isolated basins.

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