RELAX – Crustal relaxation below large impact craters inferred from novel imaging of analogue experiments

超高速撞击是太阳系的一个基本地质过程。认识大型撞击坑的一个突出问题是大型撞击坑下地壳粘性松弛对地壳流动和撞击坑底结构改变的影响。通过在模拟实验中实施新的物质流成像实验技术，该项目有望将模型陨石坑的深度、直径和形态以及模型上地壳的厚度与地壳流动和陨石坑底部裂缝的模式联系起来。通过引入高频探地雷达与数字图像相关相结合的方法来可视化地壳流动，将大大提高模拟模拟的能力，拓宽实验构造学的研究领域。这项研究可能会填补行星地质学的重要知识空白。例如，关于陨石坑底部压裂的知识直接关系到评估陨石坑下撞击后热液细胞平流热输运的持续时间、空间范围和机制，以及地球上最具经济价值的矿床的形成。此外，由模拟实验得出的陨石坑底裂缝的模式和类型可能有助于推断除地球以外的岩石行星体的地壳厚度。

Hypervelocity impact is a fundamental geological process of the solar system. An outstanding problem in understanding large-scale impact cratering concerns the effect of viscous relaxation of crust below large impact craters on crustal flow and structural modification of crater floors. By implementing novel experimental techniques of imaging material flow in analogue experiments, the project promises to relate depth, diameter and morphology of model craters as well as thickness of model upper crust to crustal flow and patterns of crater floor fractures. By introducing high-frequency ground penetrating radar in combination with digital image correlation to visualize crustal flow, the capabilities of analogue modelling will be advanced significantly and will broaden the field of experimental tectonics. The study may close important knowledge gaps in planetary geology. For example, knowledge on crater floor fracturing pertains directly to assessing the duration, spatial extent and mechanisms of advective heat transport of post-impact hydrothermal cells below impact craters as well as the formation of the economically most valuable ore deposits on Earth. Moreover, the patterns and types of crater floor fractures resulting from the analogue experiments may well aid in inferring crustal thicknesses of rocky planetary bodies other than Earth.