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: 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=691081
• 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 tectonicsone 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，作为构造高能地壳和下方流体对流地幔之间的重要桥梁地带。地幔岩石圈是地球岩石圈的次地壳部分，是大陆构造板块的最大组成部分。与下面的上覆地壳和流体地幔相比，对其演化的研究很少，也了解得很少。我的研究计划将通过在大陆地幔岩石圈构造活跃的三个目标环境中回答关键的悬而未决的问题，在我们对地球的这一地下地平线的理解方面取得切实的进展：(1)先前存在的“伤疤”是否控制着岩石圈的构造反应？(2)在某些地区，地幔岩石圈如何以及为什么被完全/部分地移走，在地表产生什么后果？(3)当深地幔岩石圈在构造板块边界地带碰撞形成山脉时，会发生什么？这项研究将在具有构造战略意义的地区探索这些问题，包括安纳托利亚高原、加拿大北极高地的尤里坎造山带、伊朗的扎格罗斯褶皱冲断带和新西兰南岛的高山板块边界带。*这项研究将由一个由本科生和研究生以及博士后研究员和助理研究员组成的多元化团队进行。我们使用计算地球动力学进行研究，研究小组正在开发先进的新的四维工具，其中我们考虑了模型在时间和三维空间维度上的演变。此外，我们将使用物理尺度的模拟模型，让我们从实验室的工作台上获得独特和详细的构造视图(这是研究行星尺度地球动力学的一个重大挑战！)作为地球科学中的一种新的和新颖的应用，我们将试验人工智能(AI)的方法，即机器学习和神经网络技术，以确定主导地球参数并对地球各种观测到的构造行为模式进行分类。将人工智能应用于地球科学并不是一种既定的做法，但它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机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全球板块构造--这是我们这个高能星球的主要谜团之一。此外，作为含金刚石火山金伯利岩管的产地，研究大陆地幔岩石圈的演化对了解加拿大矿产行业内重要资源的开发具有直接意义。在更广阔的前沿，这项研究将有助于破译金星、火星、木卫一和欧罗巴等陆地天体的地质演化，这些天体的表面构造活动与地球相比有很大不同。