Exploring plate tectonic force balances and plate boundary forces in the South Atlantic from plate motion histories and coupled global and regional geodynamic models

从板块运动历史和耦合的全球和区域地球动力学模型探索南大西洋的板块构造力平衡和板块边界力

• 批准号: 80283908
• 负责人: Professor Dr. Hans-Peter Bunge, Ph.D.
• 金额: --
• 依托单位: Department für Geo- und Umweltwissenschaften
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/80283908?language=en
• 关键词: Exploring; plate; tectonic; force; balances

The South Atlantic preserves a crucial archive of past plate motion due to its passive margin environment. Particularly important are rapid plate motion changes recorded in the spreading history of the mid-Atlantic ridge, and the Scotia and Sandwich back-arc system. Their short duration makes these changes sensitive probes into the force balance of plate motion, especially for plate boundary forces, as mantle related processes evolve on longer time-scales. We will investigate the mantle/lithosphere force balance using coupled mantle circulation and neo-tectonic models. We will pay particular attention to far-field effects which must be studied with global models to avoid influence from artificial boundary conditions. Far-field effects are expected to be relevant as indicated by preliminary modelling results suggesting that South Atlantic spreading variations are affected by near surface processes in the adjacent continents. We will assemble high-resolution (spatial and temporal) compilations of the South Atlantic spreading history, and exploit their detailed kinematic constraints to test the hypothesis that topography variations in the adjacent continents, such as the rise of the Andes or the topographic high stand of South Africa, are important factors in the tectonic evolution of the South Atlantic. Evolution of the Scotia back-arc basin will be studied with a combination of regional and global mantle flow models. Funds from this proposal will support the post-doctoral training of Stuart Clark, who brings a unique background of regional mantle flow modelling and plate reconstructions through his PhD work with Dietmar Müller, so that advanced plate reconstruction and geodynamic models can be made available to the broader SAMPLE effort.

由于其被动的边缘环境，南大西洋保留了过去板块运动的重要档案，特别重要的是大西洋中脊扩张历史中记录的快速板块运动变化以及其短暂的弧后系统。随着地幔相关过程在更长的时间尺度上演化，这些变化使得板块运动的力平衡变得敏感，特别是板块边界力，我们将使用耦合的地幔循环和新构造模型来研究地幔/岩石圈的力平衡。我们将特别关注远场效应，必须使用全球模型来研究远场效应，以避免人工边界条件的影响，初步模拟结果表明，南大西洋扩散变化受到近场影响，预计远场效应是相关的。我们将收集南大西洋扩张历史的高分辨率（空间和时间）汇编，并利用其详细的运动学约束来检验邻近大陆的地形变化的假设，例如大西洋的崛起。安第斯山脉或地形高地南非的地幔是南大西洋构造演化的重要因素，将结合区域和全球地幔流模型来研究斯科舍岛弧后盆地的演化，该提案的资金将支持博士后培训。 Stuart Clark 博士通过与 Dietmar Müller 的博士合作带来了区域地幔流建模和板块重建的独特背景，以便可以为更广泛的 SAMPLE 工作提供先进的板块重建和地球动力学模型。