Source-Transport-Trap Models for Base and Precious Metals in Basins

盆地中贱金属和贵金属的源-传输-陷阱模型

• 批准号: RGPIN-2014-05000
• 负责人: Olivo, Gema
• 金额: $ 2.19万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683637
• 关键词: Source; Transport; Trap; Models; Base

Many economic resources such as energy (petroleum & uranium) and metals (lead, zinc, copper & gold) are products of basin-scale fluid flow systems operating over long periods of time and at distinct stages of basin evolution. The potential for sedimentary basins to host economic resources is a function of the environment in which they formed, how they were deformed and how and when fluids migrated and interacted with the rocks over time. Most mineralized basins normally host only one major type of economic deposit, however, the Vazante basin in central Brazil is one of the rare examples that hosts a variety of lead and zinc deposit types and minor gold occurrences. Although it is generally recognized that processes related to sedimentation, diagenesis, deformation, fluid-rock interaction and exhumation are relevant in the formation and preservation of the various types of lead and zinc deposits, there are still important open questions about the processes responsible for the formation of economic concentrations of these metals. This is due in part to the fact that most of the previous research on basins focused only on one major aspect of the entire ore-forming process: either the metal sources, or the fluid composition or fluid flow dynamics, or the depositional mechanisms. My research program will address the unresolved issues by applying a holistic and innovative approach to investigate all aspects of the source, transport and deposition of the metals. In the next five years, my research team will focus on establishing (a) the mechanisms by which zinc and lead are liberated from possible source rocks where they occur in low concentrations; (b) how and when they are transported by hot fluids and (c) what causes the metals to precipitate in economic ore deposits. The Vazante Basin hosts an unusual type of silicate zinc deposit, as well as the typical lead-zinc sulphide deposits formed by hot fluids interacting with sedimentary rocks in the basin. Therefore, it is an ideal setting in which to investigate the mechanisms responsible for the formation of these distinct types of deposits and develop exploration models to be used in similar settings (e.g., Mackenzie Basin in Canada). We would like to test the hypothesis that the source of metals and the nature of the fluids for both types of base metal deposits are similar, but the depositional processes are different, producing the major differences in the mineralogy and composition of the mineralized areas. To attain these objectives, we will integrate robust field and laboratory work, including the state-of-the art techniques, in collaboration with experts from the various fields of geoscience, geochemistry and geophysics. The expected impacts of this research are: (1) Identification of the critical factors that control the formation of large lead and zinc deposits in sedimentary basins, and the establishment of conceptual genetic models and exploration strategies. These findings will lead to the identification of basins that are more likely to host world-class base metal deposits, particularly large silicate zinc deposits which are still rare and poorly understood; (2) Elaboration of innovative approaches integrating various disciplines, and developing new techniques to understand the processes of metal liberation from source rocks, and their transport and deposition (possibly also applicable to environmental studies); (3) Finally, it will allow for the training of highly qualified professionals (1 M.Sc and 3 Ph.D students and undergraduate students) who will learn to acquire and integrate data from various subdisciplines and to develop new methodologies and analytical techniques in a highly collaborative environment, preparing them to work in academia, government and industry.

许多经济资源，如能源（石油和铀）和金属（铅，锌，铜和金）是盆地规模的流体流动系统在盆地演化的不同阶段长期运作的产物。沉积盆地承载经济资源的潜力取决于它们形成的环境、它们如何变形以及随着时间的推移流体如何以及何时迁移并与岩石相互作用。 大多数矿化盆地通常只有一种主要的经济存款类型，然而，巴西中部的Vazante盆地是一个罕见的例子，拥有各种各样的铅和锌存款类型和小金矿点。虽然人们普遍认识到，与沉积、成岩作用、变形、流体-岩石相互作用和折返作用有关的过程与各类铅和锌矿床的形成和保存有关，但关于这些金属的经济富集的形成过程，仍然存在着重要的未决问题。这部分是由于以前对盆地的研究大多只集中在整个成矿过程的一个主要方面：金属来源，或流体成分或流体流动动力学，或沉积机制。我的研究计划将通过应用整体和创新的方法来解决尚未解决的问题，以调查金属的来源，运输和沉积的各个方面。在今后五年中，我的研究小组将着重于确定：（a）锌和铅从可能的低浓度源岩中释放出来的机制;（B）它们如何以及何时被热流体搬运;（c）是什么原因导致这些金属沉淀在经济矿床中。瓦赞特盆地拥有一种特殊类型的硅酸盐锌存款，以及典型的铅锌硫化物矿床形成的热流体与沉积岩在盆地。因此，这是一个理想的环境，在其中调查的机制，负责形成这些不同类型的矿床和开发勘探模型，用于类似的设置（例如，加拿大的麦肯齐盆地）。 我们想测试的假设，金属的来源和流体的性质为两种类型的基本金属矿床是相似的，但沉积过程是不同的，产生的主要差异的矿物学和组成的矿化区。为了实现这些目标，我们将与地球科学，地球化学和地球物理学各个领域的专家合作，整合强大的实地和实验室工作，包括最先进的技术。本研究的预期影响是：（1）识别控制沉积盆地中大型铅锌矿床形成的关键因素，并建立概念性的成因模式和勘探策略。 这些发现将有助于查明更有可能蕴藏世界级贱金属矿床的盆地，特别是大型硅酸盐锌矿床，这些矿床仍然罕见，而且人们对其了解甚少;（2）发展综合各学科的创新方法，开发新技术，以了解金属从源岩中释放的过程及其迁移和沉积（可能也适用于环境研究）;（3）最后，它将允许培训高素质的专业人员，（1名理科硕士和3名博士生和本科生）世卫组织将学习获取和整合来自各个分支学科的数据，并在高度合作的基础上开发新的方法和分析技术。环境，准备他们在学术界，政府和工业界工作。