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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633773
• 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.

拟议的研究将研究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地壳下部分，与上覆地壳相比，构成了大陆构造板块的最大组成部分。在下面的流体地幔中，它的演化很少被研究和了解，该研究项目将通过回答三个目标环境中的重要的悬而未决的问题，在我们对地球这部分的理解方面取得切实的进展。大陆地幔岩石圈现在/曾经是构造活跃的：（1）地幔岩石圈如何以及为何在某些区域被完全/部分去除以及在地表产生什么后果？；（2）当大陆地幔岩石圈在板块边界碰撞时会发生什么。 ；（3）是什么导致板块变形发生在远离板块边界的区域？该研究将在包括尤里卡在内的构造战略领域探讨这些问题。加拿大高纬度北极、新西兰南岛高山板块边界区、安纳托利亚高原和意大利亚平宁造山带的造山运动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型 4 维工具。我们考虑模型随时间和三个空间维度的演变，这些建模工具与用于全球构造的其他工具不同，因为它们结合了粘塑性流变学、多组分系统和该研究通过使用多学科自上而下的方法，在地质、地球物理、大地测量等观测约束下，对复杂耦合的地幔-地幔-岩石圈-地壳-表面进行热机械勘探的边界条件也将是地球动力学研究中的创新和独特之处。 ——通过新的地球动力学工具和方法以及有针对性的实地研究，该研究将在我们对岩石圈动力学和大陆构造如何运作的知识方面取得重大进展。对于探索我们对板块构造过程的理解中的一个根本差距——大陆板块如何以及为何具有地质活动性——地幔岩石圈是地幔热机和构造活动地壳之间的桥梁，这项研究将有助于揭示板块的驱动因素。此外，作为含金刚石火山金伯利岩管的成因地，研究大陆地幔岩石圈的演化对于了解重要地质的发育具有直接意义。在更广泛的领域，这项研究将有助于破译金星、火星、木卫一和木卫二等与地球相比表现出截然不同的表面构造活动的地球体的地质演化。