Carbon dioxide glaciers on Mars: Products of recent low obliquity epochs (?)

Three localized sets of small arcuate ridges associated with slopes in the northern polar area of Mars (∼70°N latitude) are morphologically similar to sets of drop moraines left by episodes of advance and retreat of cold-based glaciers. Comparison with other glacial features on Mars shows that these features differ in important aspects from those associated with water–ice flow. Instead, we interpret these features to be due to perennial accumulation and flow of solid carbon dioxide during recent periods of very low spin-axis obliquity.