The similarity of fluidized ejecta blankets of double-layer ejecta (DLE) craters and long run-out landslides: morphometry and modeling

对火星和地球撞击坑的综合对比分析是研究撞击坑形成过程中挥发物对开挖过程影响的一种合理而成功的方法。可以回答前一份申请中提出的主要问题。通过三维重建可以证明，里斯陨石坑的喷出物覆盖层包含一个巨大的中间壁垒，并且在形态上与火星双层喷出物（DLE）陨石坑相似。在里斯喷出物毯的两个钻孔中发现了沉积和流动过程中水存在的丰富指标。该方法可以求解DLE陨石坑的基本流体运动学以及喷出物层沉积的时空关系。在项目的过程中，很明显，内部和外部喷出物层以不同的滑坡模式移动。虽然内部喷出物层是由一个平移幻灯片，从火山口边缘和溢出的近端部分的外部喷出物相的外部更丰富的流体层移动的泥石流或碎片雪崩模式。我们观察到一个强大的地形和形态之间的相似之处，这些喷出物相，火星滑坡以及陆地上的长期运行的岩石雪崩。DLE喷出物层和滑坡的内层的一阶特征是平行于流动方向的径向（纵向）脊和槽。虽然这样的条纹似乎是快速质量运动的基本现象，但到目前为止，对它们的形成知之甚少。我们认为，它们的形成是理解流动机制的关键。它们的几何形状和间隔甚至可以允许约束流动的物理参数。在后续项目中，我们将开发一个基于Voellmy方程的数学模型，旨在模拟它们的形成。一个严格的形态分析提供了输入参数的基础，该模型。同样的特征是形成垂直于流动的延伸沟和压缩脊，其使径向/纵向脊和槽偏移。这些特征是在流动的最后增量期间，当运动的物质恢复强度时发展起来的.我们的形态测量分析包括这些特征。该提案的结果具有双重意义且影响深远：（i）DLE陨石坑和山体滑坡喷出物覆盖层表面特征的比较定量形态测量分析将证明或反驳DLE陨石坑的山体滑坡特征。(ii)将解释在快速移动的岩体上形成纵向脊和槽的基本现象。

The combined and comparative analysis of impact craters on Mars and Earth was a reasonable and successful way to investigate the effects of volatiles on the excavation process during impact cratering. Main questions raised in this former application could be answered. It could be demonstrated via three-dimensional reconstruction that the Ries crater´s ejecta blanket contains a massive intermediate rampart and is morphometrically similar to the Martian double layer ejecta (DLE) craters. Abundant indicators for the presence of water during deposition and flow were found in two boreholes of the Ries ejecta blanket. The fundamental flow kinematics as well as the spatial and temporal relationship of the ejecta layer deposition of DLE craters could be solved. In the course of the project it became obvious that the inner and outer ejecta layers move in different landslide modes. While the inner ejecta layer is formed by a translational slide that emanates from the crater rim and overruns the proximal parts of the outer ejecta facies the outer more fluid-rich layer moves in a debris flow or debris avalanche mode. We observed a strong topographic and morphologic resemblance between these ejecta facies, and Martian landslides as well as terrestrial long run-out rock avalanches. A first-order feature of the inner layer of DLE ejecta layers and landslides are radial (longitudinal) ridges and grooves parallel to the flow direction. Although such striations appear to be a fundamental phenomenon of fast mass movements their formation is so far poorly understood. We believe that their formation is key to understand the flow mechanism. Their geometry and spacing may even allow to constrain physical parameters of the flow. In the continuation project we will develop a mathematical model based on Voellmy´s equations that is aimed to simulate their formation. A rigorous morphometric analysis provides the basis of input parameters to that model. Likewise characteristic is the formation of extensional furrows and compressive ridges perpendicular to the flow that off-set the radial/longitudinal ridges and grooves. These features develop during the final increments of the flow when the moving masses regain strength. Our morphometric analysis includes these features. The outcome of this proposal is twofold and far-reaching: (i) The comparative quantitative morphometric analysis of surface features of ejecta blankets of DLE craters and landslides will prove or disprove the landslide characteristics of DLE craters. (ii) The fundamental phenomenon of the formation of longitudinal ridges and grooves on fast moving rock masses will be explained.