Evolution of fault zones in layered sand-clay sequences

断层是地球上地壳中普遍存在的结构。了解它们的力学和输运性质的演变是基础和应用地球科学许多领域的一个重要挑战。这个跨学科的研究项目旨在了解沉积盆地中层状砂粘土序列中断层带的演化，从初始应变局部化的模式到高应变断层泥的形成。在我们以前工作的基础上，我们将整合三种方法：- 实地观察层状砂-粘土序列中的断层，以测量位移梯度并确定断层泥的特征和机械特性（NRW的褐煤采石场，马来西亚沙捞越美里机场路露头），-水饱和实验中砂-粘土层饼中应变局部化的比例物理模型，使用具有准确已知属性的材料，用粒子图像测速法量化位移场，和-数值模拟，使用具有自适应网格化的有限元模型（ELFEN）来模拟我们的沙箱模型和离散元模型中的局部化发展，以研究断层泥的演化。最后，通过比较数值模型和物理模型中的位移场和应力进行验证后，将数值模型外推到地质相关的长度尺度和边界条件，以便将结果直接与现场观测结果进行比较。

Faults are ubiquitous structures in the Earth’s upper crust. Understanding the evolution of their mechanical and transport properties is an important challenge in many areas of basic and applied geosciences. This interdisciplinary research project aims to understand the evolution of fault zones in layered sand-clay sequences in sedimentary basins, from the patterns of initial strain localization to the formation of a highly strained fault gouge. Building on our previous work, we will integrate three approaches: - Field observations of faults in layered sand-clay sequences to measure displacement gradients and characterize fault gouges together with mechanical properties (Lignite quarries in NRW, Airport Road outcrop, Miri, Sarawak, Malaysia), - Scaled physical models of strain localization in sand- clay layercakes in water-saturated experiments, using materials with accurately known properties, quantifying the displacement field with Particle Image Velocimetry, and - Numerical modelling, using Finite Element models with adaptive remeshing (ELFEN) to model the development of localization in our sandbox models and discrete element models to study the evolution of fault gouge. Finally, after validation by comparison of displacement fields and stresses in the numerical and physical models, the numerical models will be extrapolated to geologically relevant length scales and boundary conditions so that the results can be directly compared with field observations.