Metallogeny of convergent and collisional plate margins through geological time

地质时期汇聚和碰撞板块边缘的成矿作用

• 批准号: RGPIN-2017-05082
• 负责人: Richards, Jeremy
• 金额: $ 2.33万
• 依托单位: Laurentian University of Sudbury
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=663325
• 关键词: Metallogeny; convergent; collisional; plate; margins; Metallogeny; convergent; collisional; plate; margins

Metallogeny of convergent and collisional plate margins through geological time:***Convergent and collisional tectonic plate margins, where one plate subducts beneath or collides with another, are the only locations where crustal materials are returned to the mantle. These materials include volatiles such as water, sulfur, and chlorine, which are critical for the solubilization and transport of metals in mantle-derived magmas, and which are exsolved again as hydrothermal fluids from those magmas upon emplacement in the upper crust. Porphyry Cu±Mo±Au and epithermal Au±Cu ore deposits are formed where the flow of these fluids is sufficiently focused and voluminous to result in precipitation of ore minerals in economic concentrations. While major advances have been made in recent years relating to ore depositional processes, the underlying magmatic and tectonic processes that give rise to “fertile” magmas (i.e., magmas with the potential to form ore deposits) are less well understood, and less well integrated into metallogenic models. The objective of this proposal is to draw together and extend research on subduction and collision zone tectonics and magmatism, with a focus on constraining the processes that affect the behaviour of metals. This is a large endeavour, and I will work collaboratively with other researchers with specialist expertise to achieve these goals. Specific areas of research will be: Phanerozoic subduction and post-subduction ore-forming processes at an Earth-system scale; the metallogeny of the lower crustal roots of magmatic arcs, where evidence for deep processing of mantle-derived metals can be observed in rare exposures; and rare Precambrian porphyry deposits that may preserve evidence of changing tectonomagmatic processes over geological time, and their effects on metallogeny.******This research has significance for the exploration and discovery of new resources of Cu, Mo, Au, and other metals, which are critical for the maintenance and growth of modern society. Discovery rates of economic deposits of these metals are falling despite increased exploration expenditures, and the industry is looking for new concepts and better models that can help predict the occurrence of ore deposits, especially in previously overlooked or covered terranes. The regional scope of the proposed research provides fundamental information about the prospectivity of magmas and volcanic arcs, which can be used to develop novel exploration strategies in mature mineral belts, and to prioritize and focus exploration in new regions. Parallel research (not part of this proposal) takes this a step further to also consider the environmental and socioeconomic impacts of mining.

通过地质时间的收敛和碰撞板边缘的金属质量：***收敛和碰撞构造板缘，其中一个板块在下面或与另一个撞击物相撞，是返回地壳材料的唯一位置。这些材料包括挥发物，例如水，硫和氯，这对于地幔衍生的岩浆中的金属的溶液和运输至关重要，并且在上壳中降落后，从这些岩浆中再次被溶解为氢液体。形成斑岩铜±mo±au和焦酸矿石沉积物，在这些烟道的流动充分集中和大量以导致经济浓度下矿石矿物质的沉淀。尽管近年来已经取得了与矿石沉积过程有关的重大进展，但引起“肥沃”岩浆（即具有形成矿床潜力的岩浆）的潜在岩浆和构造过程的理解较少，并且不太良好地集成到金属级别中。该提案的目的是结合俯冲和碰撞区构造和岩浆的研究，重点是限制影响金属行为的过程。这是一项艰巨的努力，我将与其他具有专业知识的研究人员合作，以实现这些目标。研究的特定领域将是：以地球系统量表为单位的原生代俯冲和造成后矿石形成过程；岩浆弧的下层地壳根的金属生成，可以在罕见的暴露中观察到地幔衍生金属的深度加工的证据；以及罕见的前寒武纪斑岩沉积物，这些沉积物可能保留在地质时代改变构造工艺及其对金属基质的影响的证据。这些金属的经济矿床发现率正在下降，增加了勘探支出，该行业正在寻找新的概念和更好的模型，以帮助预测矿床的发生，尤其是在先前被忽视或覆盖的地形中。拟议研究的区域范围提供了有关岩浆和火山弧的前途的基本信息，这些信息可用于制定成熟矿物带中的新型勘探策略，并在新地区优先考虑和重点探索。并行的研究（不是本提案的一部分）进一步考虑采矿的环境和社会经济影响。