This article presents U–Th–Pb and Lu–Hf detrital zircon isotope data, as well as whole-rock Sm–Nd isotope data on metasedimentary rocks from the eastern part of the Tukuringra Terrane. Our analyses show that the zircons in metasedimentary rocks are mostly early Mesozoic. The Early Mesozoic, Early Paleozoic and Neoproterozoic zircons are predominant and Early Precambrian zircons are almost absent in these rocks. The age of the youngest zircon population places a lower age limit of sedimentation at 204 Ma for the Tungala Formation (Upper Triassic, Rhaetian), at 181 Ma for the Dugda Formation (Lower Jurassic, Toarcian), and at 189 Ma for the Tangomen Formation (Lower Jurassic, Pliensbachian). Practically all Mesozoic, Paleozoic, and Neoproterozoic zircons are characterized by Neo- and Mesoproterozoic Hf-model ages (t_Hf(DM)) = 1.41–0.46 Ga, t_Hf(C) = 1.55–0.49) and Mesoproterozoic Nd-model ages (t_Nd(DM) = 1.25–1.10 Ga, t_Nd(C) = 1.31–1.14). These results indicate that the sedimentary rocks were mainly sourced from the Amur continental superterrane, but not from the southern framing of the North Asian Craton.

本文介绍了 Tukuringra 地块东部变沉积岩的 U-Th-Pb 和 Lu-Hf 碎屑锆石同位素数据，以及全岩 Sm-Nd 同位素数据。分析表明，变沉积岩中的锆石多为早中生代。这些岩石中以早中生代、早古生代和新元古代锆石为主，早前寒武纪锆石几乎不存在。最年轻的锆石群的年龄将沉积年龄下限置于 Tungala 组（上三叠统，Rhaetian）为 204 Ma，Dugda 组（下侏罗统，Toarcian）为 181 Ma，Tangomen 组为 189 Ma （下侏罗纪，普林斯巴赫阶）。几乎所有的中生代、古生代和新元古代锆石都具有新和中元古代 Hf 模型年龄 (t _Hf(DM)) = 1.41–0.46 Ga，t _Hf(C) = 1.55–0.49) 和中元古代 Nd 模型年龄（t _Nd(DM) = 1.25–1.10 Ga，t _Nd(C) = 1.31–1.14）。这些结果表明，沉积岩主要来自阿穆尔大陆超地体，而不是来自北亚克拉通南部框架。