Fluids in the continental crust: decrypting geological processes using noble gases

大陆地壳中的流体：利用稀有气体解密地质过程

• 批准号: RGPIN-2015-05378
• 负责人: Pinti, Daniele
• 金额: $ 1.6万
• 依托单位: Université du Québec à Montréal
• 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=662234
• 关键词: Fluids; continental; crust; decrypting; geological

The research program will focus on the origin and evolution of fluids in the lithosphere and the critical role they play in the geodynamical evolution of the continental crust. It will address fundamental questions about i) the duration and length of cross-formational fluid flow and its role in the crustal degassing; ii) the existence of fossil water as geological archives of the continental crust evolution; iii) the genesis and evolution of crustal fluids of economic interest, particularly geothermal fluids and shale gas.****To meet these objectives, a series of projects will be undertaken in sedimentary and hydrothermal environments - at different spatial and temporal scales. Some focus will be put on the processes responsible for vertical migration of gaseous species (methane, helium.) in aquifers, and the genesis of seepage on continents, with natural laboratory being the St. Lawrence Lowlands (QC). Studies will be aimed at quantifying methane fluxes and model the process of transport from Utica shale. These models will be translated to the Island of Anticosti where tight gas exploitation is sought. Another important aspect that will be explored is the occurrence of hundreds millions to billions years old fluids in deep mining environments and their role in mineralization along the Cadillac fault in Abitibi-Temiscamingue. Parallel to this NSERC research program, we are carrying out a detailed study of the evolution of hydrothermal fluids in the largest active geothermal systems of Mexico in order to assess their lifetime and power capacities. These hydrothermal environments are the modern analogue of the fossil epithermal ore deposits. The large chemical and isotopic database that will be acquired will be crucial to understand the relation between metals and fluid sources in these environments, a premise to future ore genesis models. The tremendous and unique expertise we are developing on geothermal systems will be also applied to the study of the geothermal capacity of some Canadian Provinces, in particular the genesis of the Banff's geothermal area.****The methodological approach to trace the origin and evolution of these "geofluids" is based on the isotopes of conservative elements, namely noble gases, for which I have a unique expertise in Canada. Being chemically inert, scarce and sourced from isotopically distinct reservoirs, noble gases are ideal fluid tracers. Several isotopes are products of radioactive decay, opening opportunities of dating fluids on timescales going to a few years to billions of years.****This research program represents a unique opportunity for young HQP to acquire a multi-disciplinary scientific, analytical and professional experience, in the study of the water cycle and its dynamic (behavior) in the continental crust, while specializing in a challenging and rewarding scientific discipline that is the noble gas geochemistry.**

该研究计划将重点介绍岩石圈中流体的起源和演变，以及它们在连续地壳的地球动力学演化中所起的关键作用。它将解决有关i）跨形成液流量的持续时间和长度及其在地壳脱气中的作用的基本问题； ii）化石水作为连续地壳进化的地质档案； iii）在不同的空间和临时量表下，将在沉积和热液环境中实现一系列项目，将在沉积和热液环境中进行一系列项目。含水层中气态物种（甲烷，氦）的垂直迁移的过程以及在大陆上的渗透发生的过程将放在垂直迁移的过程上，其中自然实验室是圣劳伦斯·低地（QC）。研究将旨在量化甲烷通量，并建模这些模型将转化为Anticosti岛，并在该岛上施加了严格的气体利用。将要探讨的另一个重要方面是，在深层采矿环境中发生了数亿至数十亿至数十亿年历史的景象及其在Abitibi-Temiscamingue沿凯迪拉克断层矿化中的作用。与该NSERC研究计划平行，我们正在详细研究墨西哥大型活跃地热系统中热液漏斗的演变，以评估其寿命和功率能力。这些热液环境是化石表现矿石沉积物的现代类似物。将获得的大型化学和同位素数据库对于了解这些环境中金属和流体源之间的关系至关重要，这是对未来矿石创世纪模型的前提。我们在地热系统上开发的巨大和独特的专业知识也将应用于研究某些加拿大省的地热能力，尤其是班夫地热区的起源。高贵的气体是化学惰性，稀缺和从同位素不同的储层中采购的，是理想的流体示踪剂。几种同位素是放射性衰减的产物，在时间尺度上约会到几年到数十亿年的开放机会。地球化学。**