Genetic Types of Mud Volcanism in the Cydonia and Acidalia Regions of Mars

Small cone/mound-shaped structures are widespread on the northern plains of Mars. They are usually interpreted as mud volcanoes because of their close morphological similarity to the Earth’s mud volcanoes (for example, in Azerbaijan and near the Sea of Azov). If this interpretation is correct, small cones/mounds could be evidence of the existence of a vast subsurface source of mud. The mud source could be formed by bottom sediments of a large water reservoir (ocean) that existed on the northern plains of Mars in the past eras of its geological history. Compared to the mud volcanoes on Earth, the morphology of the small mounds on Mars varies over a wider range. This may be due to a greater variety of mechanisms of the formation of the Martian cones/mounds. We studied the morphology of the small mounds in the Cydonia and eastern Acidalia regions, which are located near the dichotomous boundary within the northern plains of Mars. We distinguished five types of mounds, whose morphology probably characterizes the features of the water-mud reservoir.