Earth's codependent siblings: studying dynamic interactions between crust and mantle in ancient and modern continents

地球相互依存的兄弟姐妹：研究古代和现代大陆地壳和地幔之间的动态相互作用

• 批准号: RGPIN-2015-04080
• 负责人: Smit, Matthijs
• 金额: $ 1.75万
• 依托单位: University of British Columbia
• 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=679671
• 关键词: Earth; codependent; siblings; studying; dynamic

The continental crust is the cradle of our modern ecosystem, and the cornerstone of Earth's present day geochemical and plate-tectonic cycles. Over the course of its 4.0-4.5 billion-year lifetime, the continental crust has changed shape and volume through addition of new material to its roots and margins, and removal by erosion and subduction. The chemical and physical interactions between the crust and sub-continental lithospheric mantle (SCLM) are by far the most important in controlling the way continents develop. The strong mutual influence between these reservoirs causes their fate to be intimately tied together; they are truly co-dependent siblings. My research focusses on critical interface regions where the crust and mantle are in direct contact: subduction zones, and the roots of cratons and mountain belts. Through analytical geochemistry, petrology and fabric analysis, I provided new constraints on how, when and how fast geochemical and tectonic processes occur in these regions. In addition, I developed new methods for constraining these aspects. This new research program builds on these advances and investigates 5 key topics: 1) the stabilization of ancient cratonic roots, 2) orogenesis and plateau formation in the Himalaya-Tibet orogen; 3) the role of subduction in Earth's earliest tectonics; 4) eclogitization of the crust buried to mantle depth; and 5) the magmatic processes leading to kimberlite eruption. Each topic forms the basis for a clearly defined research stream, each with clear research questions, adequate approaches to answer these, and well-defined projects for training highly qualified personnel (HQP). The overall program is heavily analysis-based and particularly distinguishes itself through the breadth of methods used, which will allow broad insight and impact. The HQP will greatly benefit from this, as it will allow them to get hands-on training in cutting-edge analytical methods and develop the skills to creatively use these in answering fundamental geological questions. To ensure analytical and educational success, the project relies on a combination between my personal analytical expertise, and the leading analytical infrastructure and excellent research staff at the Pacific Centre for Isotopic and Geochemical Research (PCIGR). The program thus provides a solid and coherent framework for advancing the knowledge of our lithosphere and for fostering future research excellence.

大陆地壳是我们现代生态系统的摇篮，也是地球现今地球化学和板块构造循环的基石。在其40亿至45亿年的生命过程中，大陆地壳的形状和体积发生了变化，其根源和边缘增加了新的物质，并因侵蚀和俯冲而消失。地壳与陆下岩石圈地幔（SCLM）之间的化学和物理相互作用是迄今为止控制大陆发展方式的最重要因素。这些水库之间强烈的相互影响使他们的命运紧密联系在一起;他们是真正相互依赖的兄弟姐妹。我的研究主要集中在地壳和地幔直接接触的关键界面区域：俯冲带，以及岩石圈和山脉带的根部。通过分析地球化学，岩石学和组构分析，我提供了新的限制如何，何时以及如何快速地球化学和构造过程发生在这些地区。此外，我开发了新的方法来约束这些方面。这项新的研究计划建立在这些进展的基础上，并调查了5个关键主题：1）古代金伯利岩根的稳定性，2）喜马拉雅-西藏造山带的造山作用和高原形成; 3）俯冲在地球最早期构造中的作用; 4）埋藏至地幔深度的地壳榴辉岩化; 5）导致金伯利岩喷发的岩浆过程。每个主题都构成了一个明确定义的研究流程的基础，每个主题都有明确的研究问题，回答这些问题的适当方法，以及用于培训高素质人才（HQP）的明确定义的项目。整个计划在很大程度上是基于分析的，特别是通过所使用的方法的广度来区分自己，这将允许广泛的洞察力和影响。HQP将从中受益匪浅，因为这将使他们能够获得尖端分析方法的实践培训，并发展创造性地使用这些方法来回答基本地质问题的技能。为了确保分析和教育的成功，该项目依赖于我个人的分析专业知识，以及太平洋同位素和地球化学研究中心（PCIGR）领先的分析基础设施和优秀的研究人员。因此，该计划为推进我们的岩石圈知识和促进未来的卓越研究提供了一个坚实而连贯的框架。