Abstract—

Based on Sm–Nd data, a crustal source of iron-ore fluid was substantiated and the probability of age estimation for hydrothermal–metasomatic siderite of the Bakal Group, Southern Urals, was shown for the first time. The εNd (Т) values of siderite (from –13.4 to –17.6) plot in the field of Riphean shale and not the Precambrian rift gabbro and granite of this region. The obtained Sm–Nd age of the Bakal siderite is 970 ± 40 Ma, which is consistent with the Pb–Pb age of siderite from the major ore phase (~1000 Ma). The established age boundary coincides with tectonic restructuring, including the formation of a number of barite–polymetallic deposits, as well as ferruginous magnesite and fluorite in the Riphean deposits on the western slope of the Southern Urals.

中文翻译：

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南乌拉尔最大巴卡尔矿床的矿石流体来源和菱铁矿的 Sm-Nd 年龄

摘要-

基于 Sm-Nd 数据，铁矿流体的地壳来源得到证实，并首次显示了南乌拉尔巴卡尔群热液交代菱铁矿年龄估计的可能性。菱铁矿的 εNd (Т) 值（从 –13.4 到 –17.6）绘制在 Riphean 页岩油田中，而不是该地区的前寒武纪裂谷辉长岩和花岗岩。获得的 Bakal 菱铁矿的 Sm-Nd 年龄为 970±40 Ma，与主矿相菱铁矿的 Pb-Pb 年龄（~1000 Ma）一致。确定的年龄界限与构造重组相吻合，包括在南乌拉尔西部斜坡上的 Riphean 矿床中形成了许多重晶石-多金属矿床，以及铁质菱镁矿和萤石。