Modelling of noncylindrical folds

非圆柱屈曲褶皱是重要的结构，可用于约束变形岩石的运动学、有限应变和流变学。单相3D带扣褶皱可以通过不同的工艺形成，而这些工艺很难通过建模验证。它们的几何形状由以下因素控制：（i）主管层的厚度，（ii）体积有限应变的几何形状和大小，以及（iii）基质和层的流变性。在本研究中，我们将使用线性和非线性粘性岩石类似物进行规模化实验，以模拟纯收缩和一般收缩下的 3D 折叠。 3D 表面扫描和计算机断层扫描将展示非圆柱形褶皱如何生长以及它们的几何参数（波长、振幅等）如何随着渐进应变而变化。特别令人感兴趣的是几何参数和流变参数之间的关系，它可以用作古粘度计。由于非圆柱形褶皱在盐丘中很常见，因此从事碳氢化合物勘探和危险废物处置现场前研究的工作人员也应该对本项目的结果感兴趣。

Noncylindrical buckle folds are important structures, which can be used to constrain the kinematics, finite strain, and rheology of deformed rocks. Singlephase 3D buckle folds can develop by different processes which are hardly verified by modelling. Their geometry is controlled by: (i) the thickness of the competent layer(s), (ii) the geometry and magnitude of bulk finite strain, and (iii) the rheology of matrix and layer. In the present study we will carry out scaled experiments using linear- and nonlinear-viscous rock analogues to simulate 3D folding under pure and general constriction. 3D surface scans and computer tomography will demonstrate how noncylindrical folds are growing and how their geometrical parameters (wavelength, amplitude etc.) are changing with progressive strain. Of particular interest is the relation between geometrical and rheological parameters, which can be used as a paleoviscometer. As noncylindrical folds are frequent in salt domes, the results of the present project should also be of interest for workers dealing with hydrocarbon exploration and pre-site studies for disposal of hazardous waste.