Modelling of non-cylindrical boudins

非圆柱状石香肠是天然变形岩石中常见的变形构造，其发育过程各不相同。这些过程几乎没有实验研究。在本研究中，我们将进行规模的单相和多相实验，使用天然岩石（硬石膏层在岩盐基质）和岩石模拟物（橡皮泥），以产生非圆柱形撕裂和拉伸石香肠，这是由于脆性断裂和粘性颈缩，分别。增量运行结合计算机断层扫描分析将证明通过空间和时间的非圆柱形石香肠的增长。实验的目的是约束几何参数，这是固有的不同类型的非圆柱形石香肠，并可用于识别这种结构的性质。由于石香肠的几何形状受基质和层的流变行为控制，因此其几何参数可作为古粘度计。这些新结果将引起全世界构造地质学家的兴趣，尤其是岩石中的石香肠对于矿床的形成、石油和天然气的迁移以及盐丘中核废料的沉积可能很重要。

Noncylindrical boudins are common deformation structures in naturally deformed rocks which can develop by different processes. These processes have been hardly investigated experimentally. In the present study we will carry out scaled single-phase and polyphase experiments using natural rocks (anhydrite layer in halite matrix) and rock analogues (plasticine) to produce non-cylindrical torn and drawn boudins, which result from brittle fracture and viscous necking, respectively. Incremental runs in combination with computer-tomographic analyses will demonstrate the growth of non-cylindrical boudins through space and time. The aim of the experiments is to constrain geometrical parameters which are inherent in distinct types of non-cylindrical boudins and can be used to identify such structures in nature. As the geometry of boudins is controlled by the rheological behavior of matrix and layer, the geometrical parameters can be used as a paleoviscometer. The new results will be of interest to structural geologists worldwide, the more so as boudinage in rocks could be important for the formation of ore deposits, the migration of oil and gas, and the deposition of nuclear waste in salt domes.