Discrete Element Simulations of Cohesive Contractional Wedges: Kinematics and Mechanics of Fold and Thrust Belts

粘性收缩楔的离散元模拟：折叠带和推力带的运动学和力学

• 批准号: 1145263
• 负责人: Julia Morgan
• 金额: $ 15万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1145263&HistoricalAwards=false
• 关键词: Discrete; Element; Simulations; Cohesive; Contractional

The research will conduct numerical simulations of fold and thrust belts using the discrete element method in order to develop a refined understanding of the controls and mechanisms responsible for their structural geometries and evolution under a range of conditions. Forward modeling of this sort is an important tool for testing and refining interpretations of fold and thrust belts observed in the field, which often have limited exposure, are highly eroded, and are preserved under conditions far from those in which they were formed. Specific questions to be addressed include: (1) What physical and mechanical parameters control fault vergence in fold and thrust belts, with particular attention to the origin and evolution of the most frontal structures which are common traps for hyrocarbons? (2) What is the role of decollement and basement heterogeneity in the mechanical state and structural evolution of fold and thrust belts? And (3) What are the structural consequences of specific basement configurations and stratigraphy on fold and thrust belts? The simulations will be carried out using RICEBAL, a code developed at Rice University; 2D and 3D simulations will be carried out to examine the effects of mechanical stratigraphy, heterogeneous decollement properties and structure, and indentation. Results will be compared with natural examples, in particular, the classic Canadian cordillera and the northern Appalachians in Canada.Fold and thrust belt development represents a fundamental mountain building process and is also responsible for the formation of rich oil and gas reservoirs. Understanding the conditions responsible for distinctive frontal structures that favor hydrocarbon accumulations allow first-order predictions of locations of future prospects. The simulations carried out in this project will provide a unique, and yet safe, way to explore the associated geodynamic processes, with broad applications to many other problems. In addition, this project will enable further refinement of the discrete element method code RICEBAL, developed at Rice University, which will be made available for broader distribution for education and research through the Computational Infrastructure for Geodynamics.

该研究将使用离散元方法对褶皱带和冲断带进行数值模拟，以便深入了解在一系列条件下负责其结构几何形状和演化的控制和机制。此类正演模型是测试和完善对现场观察到的褶皱和冲断带解释的重要工具，这些褶皱和冲断带通常暴露程度有限，受到高度侵蚀，并且在远离其形成条件的条件下保存。需要解决的具体问题包括：（1）哪些物理和力学参数控制褶皱带和冲断带的断层辐合，特别关注作为碳氢化合物常见圈闭的最锋面构造的起源和演化？ （2）滑脱和基底非均质性在褶皱冲断带的力学状态和结构演化中起什么作用？ (3)特定的基底构造和地层对褶皱带和冲断带的结构影响是什么？模拟将使用莱斯大学开发的代码 RICEBAL 进行；将进行 2D 和 3D 模拟，以检查机械地层学、异质滑脱特性和结构以及压痕的影响。结果将与自然实例进行比较，特别是加拿大经典的山脉和加拿大北部的阿巴拉契亚山脉。褶皱和冲断带的发育代表了基本的造山过程，也是丰富油气藏形成的原因。了解有利于碳氢化合物聚集的独特锋面结构的条件，可以对未来前景的位置进行一阶预测。该项目中进行的模拟将提供一种独特且安全的方式来探索相关的地球动力学过程，并广泛应用于许多其他问题。此外，该项目还将进一步完善莱斯大学开发的离散元方法代码 RICEBAL，该代码将通过地球动力学计算基础设施广泛用于教育和研究。