The bridge between a convecting mantle and tectonic crust: Geodynamics of the mantle lithosphere

对流地幔和构造地壳之间的桥梁：地幔岩石圈的地球动力学

• 批准号: RGPIN-2019-06803
• 负责人: Pysklywec, Russell
• 金额: $ 4.44万
• 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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739116
• 关键词: bridge; between; convecting; mantle; tectonic

My proposed research will explore the dynamics of the mantle lithosphere as the important bridge zone between the tectonically energetic crust and fluid convecting mantle below. 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. My research program will make tangible advancements in our understanding of this subsurface horizon of the Earth by answering key outstanding questions in three targeted environments where continental mantle lithosphere is/was tectonically active: (1) Do pre-existing "scars" control the tectonic response of the lithosphere?; (2) How and why does mantle lithosphere get completely/partially removed in some regions and what are the consequences at the surface?; (3) What happens when the deep mantle lithosphere collides to form mountains at a tectonic plate boundary zone? The research will explore these questions in tectonically strategic field areas including the plateaus of Anatolia, the Eurekan Orogeny in Canada's high arctic, the Zagros fold-thrust belt in Iran, and the alpine plate boundary zone of the South Island of New Zealand. The research will be carried out by a diverse team made up of undergraduate and graduate students, and a post-doctoral fellow and research associate. We use computational geodynamics for our investigations and the research group is developing advanced new 4-dimensional tools where we consider evolution of the models through time and in three spatial dimensions. In addition, we will be using physical scaled analogue modelling that give us a unique and detailed view of the tectonics from a laboratory benchtop (a significant challenge in studying planetary-scale geodynamics!). As a new and novel application in geosciences we will experiment with approaches in artificial intelligence (AI)-namely, machine learning and neural network techniques to identify governing Earth parameters and classify the Earth's various observed modes of tectonic behaviour. This application of AI to the geosciences is not an established practice, but it is genuine discovery-based research with potential far-reaching impact. The mantle lithosphere is the bridge between the mantle thermal engine and tectonically mobile crust and this research will help reveal what drives global plate tectonics-one of the primary enigmas of our energetic planet. 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.

我提出的研究将探索地幔岩石圈的动力学，这是构造构成富含构造的地壳和在下面对流地幔的液体之间的重要桥梁区域。地幔岩石圈是地球岩石圈的亚地壳部分，是大陆构造板中最大的成分。与下面的地壳上衣和液体地幔相比，其进化很少研究且理解不足。我的研究计划将通过在三个目标环境中回答大陆地幔岩石圈是/是构造活动的三个目标环境中的关键问题，从而在我们对地球的地下地面上的理解中取得了切实的进步：（1）预先存在的“疤痕”控制着岩石圈的构造反应？ （2）地幔岩石圈如何以及为什么在某些地区完全/部分去除？表面有什么后果？ （3）当深陆岩岩石圈在构造板边界区域形成山脉时会发生什么？该研究将在构造战略性的田野区域中探索这些问题，包括安纳托利亚的高原，加拿大高北极的尤里坎造山基因，伊朗的扎格罗斯褶皱带和新西兰南岛的高山板边界区。 这项研究将由由本科生和研究生组成的多元化团队以及博士后研究员和研究助理进行。我们使用计算地球动力学进行调查，研究小组正在开发高级新的4维工具，在该工具中，我们考虑了通过时间和三个空间维度的模型演变。此外，我们还将使用物理缩放的模拟建模，从而为我们提供了实验室台式构造学的独特而详细的看法（研究行星尺度的地球动力学！）。作为地球科学中的一种新颖新颖的应用，我们将尝试使用人工智能（AI）的方法（即机器学习和神经网络技术）来识别统治地球参数并对地球各种观察到的构造行为模式进行分类。 AI在地球科学上的应用不是既定的实践，而是真正的基于发现的研究，具有潜在的深远影响。地幔岩石圈是地幔热发动机和构造移动地壳之间的桥梁，这项研究将有助于揭示驱动全球板块构造的原因 - 我们能量行星的主要谜团之一。同样，作为钻石轴承木材金伯利特管的起源的地点，对大陆地幔岩石圈的演变的研究对理解加拿大矿物工业内重要资源的发展具有直接的影响。在更广泛的边界，这项研究将有助于解读与地球相比的地面构造活动，如金星，火星，IO和欧罗巴等地质的地质演化。