U-Pb dating of cassiterite and zircon from the Yazov granite (Transbaikalia region, Eastern Siberia, Russia) and cassiterite from spatially associated tin mineralization in the Tuyukan ore district in the Tonod uplift was conducted using in situ laser ablation inductively coupled plasma mass spectrometry. These analyses allow comparison of isotopic systematics for both minerals, especially related to transport in granitic magma. These data are also useful for understanding possible genetic links between the granite and the tin mineralization. Most of the U-Pb zircon analyses define a 206Pb/238U age of 719 ± 15 Ma for the granite; in addition, several zircon cores define an inheritance age of 1839 ± 21 Ma. U-Pb data for 10 nearly concordant analyses of disseminated cassiterite from the same samples yield a 206Pb/238U age of 1838 ± 34 Ma. This is the first documented evidence of cassiterite inheritance in granitic magma. These data indicate the robust character of U-Pb isotope systematics in cassiterite, comparable to that in zircon. The presence of numerous inclusions of cassiterite in zircon from the Yazov granite (revealed by nanotomography) supports the interpretation of inherited cassiterite included during Neoproterozoic zircon crystallization. The data indicate that high tin concentrations in the Yazov granite are due to the incorporation of older cassiterite crystals from country rock, not coeval cassiterite crystallization. Cassiterite samples from two ore occurrences spatially associated with the Yazov granite yield Pb-Pb isochron ages of 1.86–1.82 Ga, indicating that tin mineralization occurred in the Paleoproterozoic, nearly 1 Ga before emplacement of the Yazov granite. Tin mineralization of the ore region is probably related to ~ 1.85 Ga Chuya-Kodar tin-bearing granitic rocks that host tin deposits. These results have broad implications for understanding how critical elements, such as tin, may become enriched in rare-metal granites and how they are related to regional to global geodynamic processes.

中文翻译：

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LA-ICPMS U-Pb 测年揭示了东西伯利亚 Yazov 花岗岩中锡石的遗传：对锡矿化的影响

使用原位激光烧蚀电感耦合等离子体质谱法对 Yazov 花岗岩（俄罗斯东西伯利亚外贝加尔地区）的锡石和锆石以及 Tonod 隆起 Tuyukan 矿区空间伴生锡矿化的锡石进行 U-Pb 定年。这些分析允许比较两种矿物的同位素系统学，特别是与花岗岩岩浆中的输运有关的矿物。这些数据也有助于了解花岗岩和锡矿化之间可能的遗传联系。大多数 U-Pb 锆石分析确定花岗岩的 206Pb/238U 年龄为 719 ± 15 Ma；此外，几个锆石核定义了1839±21 Ma的继承年龄。对来自相同样品的播散锡石进行 10 次几乎一致分析的 U-Pb 数据得出 206Pb/238U 年龄为 1838 ± 34 Ma。这是花岗岩岩浆中锡石遗传的第一个文献证据。这些数据表明锡石中 U-Pb 同位素系统的稳健特征，与锆石中的相当。Yazov 花岗岩锆石中大量锡石包裹体的存在（通过纳米断层扫描显示）支持对新元古代锆石结晶过程中包含的继承锡石的解释。数据表明 Yazov 花岗岩中的高锡浓度是由于掺入了来自围岩的较旧锡石晶体，而不是同时期锡石结晶。来自与 Yazov 花岗岩空间相关的两个矿点的锡石样品产生 1.86-1.82 Ga 的 Pb-Pb 等时线年龄，表明锡矿化发生在古元古代，在 Yazov 花岗岩就位前近 1 Ga。该矿区的锡矿化可能与~1.85 Ga Chuya-Kodar 含锡花岗岩有关，这些花岗岩含有锡矿床。这些结果对于理解锡等关键元素如何在稀有金属花岗岩中富集以及它们如何与区域到全球地球动力学过程相关具有广泛的意义。