Mars has several different types of slope feature that resemble aqueous flows. However, the current cold, dry conditions are inimical to liquid water, resulting in uncertainty about its role in modern surface processes. Dark slope streaks were among the first distinctive young slope features to be identified on Mars and the first with activity seen in orbital images. They form markings on steep slopes that can persist for decades, and the role of water in their formation remains a matter of debate. Here I analyse the geomorphic features of new slope streaks using high-resolution orbital images. Comparison of images before and after streak formation reveal how this process affects the surface and provides information about the cause. These observations demonstrate that slope streaks erode and deposit material in some instances. They also reveal that streaks can jump slopes and may be erosive very near their termini. These observations support a formation model where dark slope streaks form as ground-hugging, low-density avalanches of dry surface dust. Such streaks need not be treated as Special Regions for planetary protection.

火星具有类似于水流的几种不同类型的坡度特征。然而，当前的寒冷，干燥条件不利于液态水，导致不确定其在现代地表工艺中的作用。暗坡条纹是火星上最早发现的独特年轻斜坡特征之一，也是在轨道影像中发现的首个活跃特征之一。它们在可以持续数十年的陡坡上形成标记，而水在其形成中的作用仍是一个有争议的问题。在这里，我使用高分辨率轨道图像分析了新的斜坡条纹的地貌特征。比较形成条纹之前和之后的图像，可以发现此过程如何影响表面并提供有关原因的信息。这些观察结果表明，在某些情况下，斜坡条纹会腐蚀并沉积材料。他们还发现，条纹可能会跳下斜坡，并且在靠近终点的地方可能会腐蚀。这些观察结果支持了一个地层模型，在该模型中，深色的斜坡条纹形成为地面拥抱的低密度干燥表面粉尘雪崩。这样的条纹不必视为行星保护的特殊区域。