Geological and mineralogical data are reported on the manganese occurrences of the Olkhon terrane (Western Baikal region), which are localized in metadolerites of the Ustkrestovsky Complex, high-temperature mafic hornfels, granites, calcitic marbles and calciphyres, and occasionally are developed as separate veins in gneiss granites or small lenses in quartzites. Most of them are made up of high-temperature mineral assemblages (Opx + Cpx + Pl + Ilm ± Grt ± Bt ± Amp), the main manganese carriers in which are ferrorhodonite (33–36 wt % MnO), orthopyroxene (6–12 wt % MnO), and ilmenite (3–16 wt % MnO). Obtained data are in conflict with traditional concepts that these rocks are gondites (manganese-rich metamorphosed sediments) or that manganese flux in carbonate sediments was related to the volcanic activity that occurred simultaneously with sedimentation at about 500 Ma. The diversity of manganese occurrences was produced by metasomatic processes that occurred almost simultaneously with regional metamorphism and emplacement of subalkaline mafic bodies during collisional tectonogenesis (about 470 Ma).

中文翻译：

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贝加尔湖西部地区Olkhon Terrane锰矿的成因

地质和矿物学数据报道了Olkhon地貌（西贝加尔地区）的锰矿床，这些矿床分布在Ustkrestovsky Complex的变质岩，高温黑铁质角铁，花岗岩，钙质大理石和钙锈石中，偶尔会形成单独的脉在片麻岩花岗岩中或在石英岩中的小透镜中。它们大多数是由高温矿物组成的（Opx + Cpx + Pl + Ilm±Grt±Bt±Amp），其中锰的主要载体为丝光辉石（33–36 wt％的MnO），邻苯二茂铁（6–12 wt％的MnO）和钛铁矿（3–16 wt％的MnO）。所获得的数据与传统观念相矛盾，传统观念认为这些岩石是冈底石（富含锰的变质沉积物），或者碳酸盐沉积物中的锰通量与在约500 Ma沉降同时发生的火山活动有关。锰发生的多样性是由交代过程产生的，这种交代过程在碰撞构造发生过程中（约470 Ma）几乎与区域变质作用和亚碱性镁铁质岩体的侵入同时发生。