Earth Sciences Postdoctoral Research Fellowship Award

EAR-9505217 Lithgow-Berelloni这位研究员建议根据简单的地幔流动模型和详细的板块构造重建来计算地球历史最后65年的全球板内应力场。方法是通过仔细比较现有的各种地质和地球物理数据集(例如，板内应力数据、古应力指标、地震、重力和热流剖面等)，首先检验全球尺度地幔环流可以解释相对大范围(500公里)的板内应力状态和地质变化的假设。这一结果将作为评估小尺度动态特征的重要性的基线，例如局部上升流和区域尺度地壳非均质性。将使用详细的地震层析成像模型对北美西部进行区域研究，以了解全球动力学过程对落基山脉挤压区、盆地和山脉伸展以及加州走滑变形三种应力体制发展的影响。这项工作在破译神秘的板内构造特征的机制方面具有远远超出地方性应用的潜力；应力场的演变是理解地幔对流的一个缺失的关键。

EAR-9505217 Lithgow-Bertelloni The Fellow proposes to calculate the global intraplate stress field for the last 65 My of EarthOs history based on simple models of mantle flow and detailed plate tectonic reconstructions. The approach is to test first the hypothesis that global scale mantle circulation can explain relatively large-scale (500 km) intraplate variations in stress regimes and geology, by carefully comparing a large variety of existing geological and geophysical data sets (e.g., intraplate stress data, paleostress indicators, seismic, gravity, and heat flow profiles, etc.). The results will serve as a baseline for assessing the importance of smaller scale dynamic features, such as localized upwellings, and of regional scale crustal heterogeneities. A regional study using detailed seismic tomography models will be carried out for Western North America, to understand the influence of global dynamic processes on the development of the three types of stress regimes represented by the Rocky Mountains compressional region, the Basin and Range extension and the strike-slip deformation in California. This work has the potential to reach far beyond parochial applications in deciphering the mechanics of enigmatic intraplate tectonic features; evolution of the stress field is one missing key to understanding mantle convection.