Abstract Plutonic associations in orogenic belts are potent indicators of multi-stage fractionation of primitive arc magmas and growth of island-arc crust under evolving redox conditions in ancient subduction zones. Ildeus-Lucha ultramafic–mafic complex (ILC) was emplaced at 232–233 Ma within the Mesozoic Stanovoy convergent margin and subsequently underwent multi-stage hydrothermal alteration and greenschist to amphibolite facies metamorphism (~140 Ma), followed by adakite and K-lamprophyre magmatism (114–117 Ma). Dunite, wehrlite, pyroxenite and gabbro in the ILC are composed of olivine, clinopyroxene, orthopyroxene, plagioclase and late-magmatic amphibole. Mineral compositions in the ILC are typical of island-arc plutonic complexes characterized by early crystallization of orthopyroxene, plagioclase intercumulus and presence of magmatic amphibole. Ultramafic-mafic rocks display high-field strength (HFS) element depletions coupled with large-ion lithophile (LIL) element enrichments, indicating formation via crystal fractionation of mafic primary magma derived from a subduction-related mantle source. Some ultramafic rocks from the ILC contain native metals (W, Pt, Au, Ag, Zn, Bi) and intermetallic compounds (Cu-Au-Ag, Pt-Rh-Pd, Cu-Sn-Zn, etc.) included in silicate minerals, or observed as discrete phases in the finer-grained silicate-oxide-sulfide matrix. Textural evidence and association with either primary (magmatic) or secondary (metasomatic or metamorphic) mineral phases, suggest either magmatic (high-temperature) or metasomatic (low-temperature) origin of metals and metallic compounds. The following models of their formation can be proposed on the basis of the presented data: a) crystallization (W and, possibly, Pt) from metal-rich arc magmas under unusually reduced conditions in subduction-related lithosphere; b) formation from magmatic sulfides during pervasive serpentinization and release of abiogenic hydrocarbons and c) precipitation from chlorine-rich, saline aqueous fluids associated with collision-related metasomatism of the Stanovoy island arc crust.

中文翻译：

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Stanovoy 移动带（俄罗斯远东）俯冲相关超镁铁质岩石中的原生金属和金属间化合物：对俯冲带氧化还原非均质性的影响

摘要 造山带中的深成体组合是古俯冲带演化氧化还原条件下原始弧岩浆多阶段分馏和岛弧地壳生长的有力指标。Ildeus-Lucha 超镁铁质-镁铁质杂岩体 (ILC) 位于中生代 Stanovoy 收敛边缘内的 232-233 Ma 处，随后经历了多阶段热液蚀变和绿片岩至角闪岩相变质作用（~140 Ma），其次是埃达克岩和钾盐岩岩浆作用（114-117 Ma）。ILC中的纯辉石、辉石、辉石和辉长岩由橄榄石、单斜辉石、斜辉石、斜长石和晚岩浆角闪石组成。ILC 中的矿物成分是典型的岛弧深成岩复合体，其特征是斜方辉石的早期结晶，斜长石积云和岩浆闪石的存在。超基性-基性岩表现出高场强 (HFS) 元素耗尽和大离子亲石性 (LIL) 元素富集，表明通过源自俯冲相关地幔源的基性原生岩浆的晶体分馏形成。一些来自 ILC 的超基性岩含有天然金属（W、Pt、Au、Ag、Zn、Bi）和金属间化合物（Cu-Au-Ag、Pt-Rh-Pd、Cu-Sn-Zn 等），包含在硅酸盐中矿物，或在细粒硅酸盐-氧化物-硫化物基质中观察到的离散相。纹理证据以及与原生（岩浆）或次生（交代或变质）矿物相的关联，表明金属和金属化合物的岩浆（高温）或交代（低温）起源。根据所提供的数据，可以提出以下它们的形成模型： a) 在与俯冲相关的岩石圈中，在异常减少的条件下，富金属弧岩浆的结晶（W 和可能的 Pt）；b) 岩浆硫化物在普遍蛇纹石化和非生物碳氢化合物释放过程中的形成，以及 c) 与 Stanovoy 岛弧地壳碰撞相关交代作用相关的富氯咸水流体的沉淀。