The Actively forming seafloor Sulfide mineralization in the Kolumbo volcano (ASK): source of metals in an arc-related magmatic-hydrothermal system

全球人口的快速增长以及能源和技术向低碳排放社会的重大转变，都极大地增加并深刻地改变了我们对原材料的需求。尽管循环经济有所改善，但获得新的初级原材料，包括关键原材料至关重要。确保获得新原料的可能目标之一是在浅海底火山弧中形成的岩浆热液矿床，通常称为混合浅成热液火山成因块状硫化物矿床。这些矿床均富集贵金属（Ag、Au）、贱金属（Cu、Pb和Zn）和临界/痕量金属（As、Bi、Ga、Ge、Hg、Sb、Se、Te和Tl）。尽管具有经济意义，但它们的起源仍然没有得到很好的描述。一个长期存在的问题是矿床中富集的金属的来源。与岩浆分异有关的挥发性损失通常被解释为火山弧中金属流动的有效机制，但在地壳中源自海水的热液循环过程中也会流动大量金属，可能是另一种金属来源。这些过程在何种程度上有助于混合浅成热液-VMS矿床的矿化尚不清楚。对一个活跃形成的存款的研究将提供有关金属来源及其地球化学路径的重要信息，位于希腊5 Ma至现在爱琴海火山弧中的Kolumbo浅海底弧火山，是一个活跃的热液系统，目前形成高As，Ag，Au，Hg，Sb和Tl含量的多金属VMS矿化。Kolumbo热液系统代表了与大陆边缘火山作用有关的极少数已知的混合活性类似物类型的浅成热液-VMS矿化。此外，基底岩石，代表潜在的金属源区，在邻近的岛屿露头。因此，它是一个完美的天然实验室，可以从源头到水槽研究整个系统。该项目旨在采用一种创新方法，重点关注Kolumbo多金属VMS存款的金属汇和金属来源，以确定Kolumbo硫化物矿化中富集的金属的来源。将利用最先进的整体岩石和现场分析，结合数值模拟，对Kolumbo火山的矿化烟囱、火山岩和基底岩性进行彻底研究。该项目是矿石地质学领域的开创性项目，因为它采用了大陆边环境中活跃形成存款的整体方法，并符合DOME特别优先方案的范围。所产生的独特数据库将提供对地壳尺度金属通量的深入了解。能够精确地描述金属来源将对理解矿石存款形成具有重要意义，不仅对Kolumbo，而且对混合低温VMS。

Rapid global population growth and major energy and technological shifts towards low carbon emission society both highly increase and deeply modify our needs for raw materials. Despite improvement of a circular economy, access to new primary raw materials, including critical raw materials, is crucial. One of the possible targets to secure access to new raw materials are magmatic-hydrothermal ore deposits which form in shallow submarine volcanic-arcs and which are often referred to as hybrid epithermal-volcanogenic massive sulfide (VMS) deposits. These deposits are variably enriched in precious metals (Ag, Au), base metals (Cu, Pb and Zn) and critical/trace metals (As, Bi, Ga, Ge, Hg, Sb, Se, Te and Tl). Despite the economic significance, their genesis is still not well characterized. A long standing question is the source of the metals enriched in the deposits. Volatile loss associated with magmatic differentiation is commonly interpreted as an efficient mechanism for mobilizing metals in volcanic arcs but large mass of metals is also mobilized during seawater-derived hydrothermal fluid circulation in the crust and could represent an alternative metal source. The extent to which either of these processes contributes to mineralization in the hybrid epithermal-VMS deposits is not known. Investigation of an actively forming deposit will provide essential information about the sources of metals and their geochemical path. The Kolumbo shallow submarine arc-volcano, located in the 5 Ma-to-present Aegean volcanic arc in Greece, hosts an active hydrothermal system currently forming polymetallic VMS mineralization with high As, Ag, Au, Hg, Sb and Tl contents. The Kolumbo hydrothermal system represents one of the very few known hybrid active analogue style of epithermal-VMS mineralization associated with continental margin volcanism. Furthermore, basement rocks, representing the potential metal source areas, outcrop in the neighboring islands. As such, it is a perfect natural laboratory to investigate the entire system from source to sink. This project aims to characterize the sources of the metals enriched in Kolumbo sulfide mineralization using an innovative method which focuses both on the metal sink and the metal sources of Kolumbo’s polymetallic VMS deposit. Mineralized chimneys, volcanic rocks and basement lithologies from Kolumbo’s volcano will be thoroughly studied using state-of-the art whole rock and in-situ analyses coupled to numerical modelling. This project is ground breaking in the field of ore geology due to the holistic approach of an actively forming deposit in a continental margin environment and fits within the scope of the DOME Special Priority Programme. The unique database generated will provide insight into of metal fluxes at a crustal scale. Being able to precisely characterize the metal sources will have important implications on the understanding of ore deposit formation, not only for Kolumbo but also for hybrid epithermal-VMS.