Geodynamics of the continental mantle lithosphere: Investigations into active and ancient evolution of continental plate boundaries and interiors

大陆地幔岩石圈的地球动力学：大陆板块边界和内部的活跃和古代演化研究

• 批准号: RGPIN-2014-06003
• 负责人: Pysklywec, Russell
• 金额: $ 3.79万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611969
• 关键词: Geodynamics; continental; mantle; lithosphere; Investigations

The proposed research will investigate the dynamics of the continental mantle lithosphere and its relationship to crustal tectonics. The mantle lithosphere is the sub-crustal portion of the Earth’s lithosphere and makes up the largest component member of the continental tectonic plates. Compared to the overlying crust and fluid mantle below, its evolution is little studied and poorly understood. The research program will make tangible advancements in our understanding of this part of the Earth by answering important outstanding questions in three targeted environments where continental mantle lithosphere is/was tectonically active: (1). How and why does mantle lithosphere get completely/partially removal in some regions and what are consequences at the surface?; (2) What happens when continental mantle lithosphere collides at a plate boundary zone?; (3) What causes episodes of “intraplate” tectonics where plate deformation occurs distant from plate boundaries? The research will explore these questions in tectonically strategic field areas including the Eurekan Orogeny in Canada’s high arctic, the alpine plate boundary zone of the South Island of New Zealand, the plateaus of Anatolia, and the Apennine orogen of Italy. We use computational geodynamics for research and are developing advanced new 4-dimensional tools for this work, where we consider evolution of the models through time and in three spatial dimensions. The modelling tools are distinguished from others used for global tectonics as they incorporate viscous-plastic rheologies, multi-component systems, and boundary conditions that allow for the thermomechanical exploration of the complex coupled mantle-mantle lithosphere-crust-surface. The research will also be innovative and distinct among geodynamics studies by using a multidisciplinary top-down methodology where observational constraints--geological, geophysical, geodetic--are integrated directly into the computational analyses. With the new geodynamics tools and methodology and the targeted field studies, the research will make significant progress in our knowledge of lithospheric dynamics and how continental tectonics works. The proposed research is significant for exploring what is a fundamental gap in our understanding of plate tectonic processes—how and why continental plates are geologically active. The mantle lithosphere is the bridge between the mantle thermal engine and tectonically active crust and this research will help reveal what drives plate tectonics on our active Earth. Also, as the site for the genesis of diamond bearing volcanic kimberlite pipes, the study of the evolution of the continental mantle lithosphere has direct implications for understanding the development of important resources within Canada’s mineral industry. Across a broader frontier, the research will help decipher the geologic evolution of terrestrial bodies such as Venus, Mars, Io, and Europa that display much different surface tectonic activity compared to Earth.

拟议的研究将调查大陆地幔岩石圈的动力学及其与地壳构造的关系。地幔岩石圈是地球岩石圈的亚地壳部分，是大陆构造板块中最大的组成部分。与上覆地壳和下伏流体地幔相比，它的演化研究很少，了解也不多。该研究计划将通过回答三个目标环境中重要的悬而未决的问题，使我们对地球这一部分的理解取得切实的进展，其中大陆地幔岩石圈是/是构造活动：（1）。地幔岩石圈在某些地区是如何和为什么被完全/部分地移走的，在地表有什么后果？(2)当大陆地幔岩石圈碰撞到板块边界带时会发生什么？(3)是什么导致了板块变形发生在远离板块边界的“板内”构造事件？这项研究将探讨这些问题的构造战略领域，包括尤里卡造山运动在加拿大的高北极，新西兰南岛的高山板块边界区，安纳托利亚高原，和亚平宁造山带的意大利。 我们使用计算地球动力学进行研究，并正在为这项工作开发先进的新四维工具，我们考虑模型在时间和三维空间中的演变。建模工具与其他用于全球构造的工具不同，因为它们结合了粘塑性流变学，多组分系统和边界条件，允许复杂耦合的地幔-地幔岩石圈-地壳-表面的热机械勘探。这项研究还将采用多学科自上而下的方法，将地质、地球物理、大地测量等观测制约因素直接纳入计算分析，从而在地球动力学研究中具有创新性和独特性。随着新的地球动力学工具和方法以及有针对性的野外研究，该研究将在我们对岩石圈动力学和大陆构造如何运作的认识方面取得重大进展。 这项研究对于探索我们对板块构造过程的理解中的一个根本性空白--大陆板块如何以及为什么地质活动--具有重要意义。地幔岩石圈是地幔热动力和构造活动地壳之间的桥梁，这项研究将有助于揭示是什么驱动了我们活动地球上的板块构造。此外，作为含金刚石的火山金伯利岩管的成因的网站，大陆地幔岩石圈的演化的研究有直接的影响，了解加拿大的矿产工业内的重要资源的发展。在更广泛的领域，这项研究将有助于破译金星、火星、木卫一和木卫二等地球天体的地质演化，这些天体与地球相比显示出非常不同的表面构造活动。