The Rosen copper veins in southeastern Bulgaria are recognized for the first time as an iron oxide-copper-gold (IOCG) district. The veins are located in the East Srednogorie segment of the Carpathian-Balkan calc-alkaline volcano-plutonic arc and were formed during an end-stage interval of extreme slab rollback and intra-arc rifting, which gave rise farther east to seafloor spreading in the Western Black Sea basin. The resulting submarine volcano-sedimentary rift basin is dominated by intermediate to mafic shoshonitic to ultrapotassic volcanism and subsidiary gabbro to syenite intrusion. The E- to NE-striking veins define a NW-striking alignment along the western contact of the syenite-dominated Rosen pluton, inferred to be part of a large ring dike. More than 40 veins, the most important formerly mined to depths as great as 1,000 m, contain an early, pegmatoidal, calcic-potassic assemblage followed by predominant magnetite (including the mushketovite variety), chlorite, and carbonates but also quartz, chalcopyrite, pyrite, and numerous other metallic minerals, which combine to give an unusual Fe-Cu-Au-Mo-Co-Ni-U-light rare earth element (LREE)-W-Bi-Zn-Pb geochemical signature. The close correlation between Fe, Cu, U, and LREEs is evident even in the flotation tailings. Vein molybdenite was dated during this study at 80.6 ± 0.4 Ma, which is similar to a U-Pb zircon age for monzosyenite from the Rosen pluton. The mineralogic and compositional features of the Rosen district are comparable to those of well-known IOCG deposits worldwide and geometrically similar to the vertically extensive IOCG veins in the Coastal Cordillera province of northern Chile. The subsidiary granitophile signature that accompanies the characteristic siderophile IOCG suite was also recognized recently at the giant Olympic Dam deposit in South Australia and elsewhere. Although no exposed intrusion is definitively implicated in the genesis of the Rosen veins, coexisting gabbro and syenite fluid sources may be hypothesized at depth in or beneath the coeval ring dike.

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保加利亚罗森：新近认可的氧化铁-铜-金矿区

保加利亚东南部的罗森铜矿脉首次被公认为是氧化铁-铜-金（IOCG）区。这些脉位于喀尔巴阡-巴尔干钙碱性火山-深成弧的东斯雷德诺戈里部分，形成于极板回滚和弧内裂谷的末期，这使得海床向东延伸至海底扩展西部黑海盆地。形成的海底火山-沉积裂谷盆地以中，镁铁质岩浆岩，超钾质火山岩和次生辉长岩为正长岩侵入为主。从E到NE的撞击脉线定义了沿着以硒矿为主的Rosen子体的西接触的NW撞击路线，据推测这是大环形堤的一部分。40多个矿脉，最重要的是以前开采的深度达1,000 m，包含早期的柱状，钙-钾组合，然后是主要的磁铁矿（包括Mushketovite变种），绿泥石和碳酸盐，而且还包含石英，黄铜矿，黄铁矿和许多其他金属矿物，这些矿物组合在一起形成了不寻常的Fe-Cu-Au -Mo-Co-Ni-U-轻稀土元素（LREE）-W-Bi-Zn-Pb地球化学特征。即使在浮选尾矿中，Fe，Cu，U和LREE之间也存在密切的相关性。在这项研究中，脉状辉钼矿的年代定为80.6±0.4 Ma，这与Rosen岩体中的辉长岩的U-Pb锆石年龄相似。罗森地区的矿物学和组成特征与全球著名的IOCG矿床的矿物学和组成特征相当，并且在几何上类似于智利北部沿海科迪勒拉省垂直延伸的IOCG矿脉。最近，在南澳大利亚州和其他地区的巨型奥林匹克大坝矿床中也发现了具有特色的嗜铁生物IOCG套件附带的亲嗜谷粒的辅助标志。尽管在罗森静脉的起源中没有明确地暗示裸露的侵入，但是可以假设在同时存在的辉长岩和正长岩脉源位于该先祖环堤的深处或下方。