Mobilization of Metals in Oceanic core complex (MOMO): source to sink investigation of gabbroic-ultramafic hosted VMS deposits

大洋核心复合体 (MOMO) 中金属的流动：辉长岩-超镁铁质 VMS 矿床的源到汇研究

• 批准号: 460092619
• 负责人: Dr. Malte Junge, Ph.D.
• 金额: --
• 依托单位: Institute of Mineralogy and Petrography
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/460092619?language=en
• 关键词: Mobilization; Metals; Oceanic; core; complex

Mineral resources are of major importance for many industrial sector supply chains. Developing further mineral extraction within the European Union will be a necessity in the next decades. Classic ore deposits, however, are harder to discover, especially in Europe, despite worldwide massive exploration budgets, and unconventional ore deposits appears as new potential alternative. Among these are gabbroic-ultramafic hosted volcanogenic massive sulfide (VMS) deposits, which are part of the larger group of VMS deposits. These deposits are associated with Oceanic Core Complexes (OCC), uplifted, dome-like exposures of the lower oceanic crust that have been exhumed by tectonic extension along slow to ultra-slow oceanic spreading centers. These peculiar deposits show specific enrichment in Au-Cu-Co-Ni and are future potential polymetallic ore deposits mined either from land or from the seafloor. They have been, however, poorly characterized on-land partly because they were misclassified as hydrothermally altered magmatic ore deposits and partly because their genetic model remains poorly understood. In this project we propose to locate the source of the metals enriched in gabbroic-ultramafic hosted VMS deposits by investigating the ocean drilling program (ODP) Hole 735B located on the Atlantis Bank OCC, in the southwest Indian ridge and the Troodos ophiolite in Cyprus. The ODP Hole 735B recovers gabbroic rocks down to 1508 meters below seafloor (mbsf) and shows evidence for high temperature alteration zones where possible metal mobilization occurred during high temperature hydrothermal fluid circulation. Similarly, the Troodos ophiolite shows evidences for relics of OCC with seafloor-related high temperature hydrothermal alteration and associated massive sulfide mineralization. We also propose to determine the characteristics, extent and intensity of alteration halos and element dispersion related to ultramafic-hosted VMS mineralization from the western Limassol Forest complex within the Troodos ophiolite. The combined study areas are the perfect natural laboratories for implementing a mineral system approach from source to sink; essential for developing the genetic model of gabbroic-ultramafic hosted VMS deposits. Additionally, we will develop a preliminary exploration model for this deposit type.

矿产资源对许多工业部门的供应链至关重要。在未来几十年内，在欧洲联盟内进一步开发矿物开采将是必要的。然而，经典矿床很难发现，特别是在欧洲，尽管世界范围内有大量的勘探预算，非常规矿床似乎是新的潜在替代品。其中包括辉长岩-超镁铁质火山成因块状硫化物（VMS）矿床，这是VMS矿床的一部分。这些矿床与大洋核杂岩（OCC）有关，OCC是大洋下地壳隆起的圆顶状暴露，是沿着慢速至超慢速大洋扩张中心的构造伸展作用所挖出的。这些特殊的矿床显示出Au-Cu-Co-Ni的特定富集，是未来从陆地或海底开采的潜在多金属矿床。然而，它们在陆地上的特征很差，部分原因是它们被错误地归类为热液蚀变岩浆矿床，部分原因是它们的成因模式仍然知之甚少。在这个项目中，我们建议通过调查位于亚特兰蒂斯银行OCC的海洋钻探计划（ODP）孔735 B，在西南印度洋脊和塞浦路斯的特罗多斯蛇绿岩，来定位富集在辉长岩-超镁铁质VMS矿床中的金属的来源。ODP孔735 B恢复辉长岩深至海底（mbsf）以下1508米，并显示高温蚀变区的证据，在高温热液流体循环期间可能发生金属活动。同样，Troodos蛇绿岩显示了OCC遗迹的证据，与海底相关的高温热液蚀变和相关的块状硫化物矿化。我们还建议确定特罗多斯蛇绿岩内西部利马索尔森林杂岩中与超镁铁质岩托管VMS矿化相关的蚀变晕和元素分散的特征、范围和强度。合并后的研究领域是实施从源到汇的矿物系统方法的完美天然实验室;对于开发辉长岩-超镁铁质VMS矿床的成因模型至关重要。此外，我们还将为该存款类型建立初步的勘探模式。