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.

由于其被动边缘环境，南大西洋保留了过去板运动的关键档案。特别重要的是在大西洋山脊的扩散历史以及斯科舍省和三明治背面系统中记录的快速板运动变化。它们的短持续时间使这些变化的问题敏感到板运动的平衡，尤其是对于板边界力的平衡，随着地幔相关的过程在较长的时间尺度上演变。我们将使用耦合的地幔循环和新建筑模型研究地幔/岩石圈力平衡。我们将特别注意远场效应，必须使用全球模型研究，以避免对人工边界条件的影响。如初步建模结果所表明的那样，远场效应有望与之相关，表明南大西洋的扩展变化受相邻大陆近表面过程的影响。我们将组装南大西洋传播历史的高分辨率（空间和临时）汇编，并利用其详细的运动学约束，以检验以下假设：相邻大陆的地形变化，例如安第斯山脉或南非地形的崛起，是南非地形高架的重要因素，是南方人的建立阶级进化的重要因素。斯科舍省后弧盆地的演变将与区域和全球地幔流模型的结合进行研究。该提案的资金将支持斯图尔特·克拉克（Stuart Clark）的博士后培训，他通过与DietmarMüller的博士学位合作，为区域性地幔流程建模和板块重建提供了独特的背景，因此可以为更广泛的样本提供了高级板块重建和地球动体模型。