Abstract
Poleward-facing slopes are preferentially flattened more than equatorward-facing slopes in the middle latitudes of Mars. In this study, we confirm whether the process of the preferential flattening were active during the Amazonian, based on statistical investigation of impact craters on the relatively new surface of the Alba Patera region. In most cases, the angle of the poleward-facing wall is lower than that of the equatorward-facing wall of each crater at latitudes from 35 N to over 50 N. Shallow craters have both poleward-facing walls, the surface of which seems to be covered with ice-rich material, and floors which tend slightly to incline toward poleward. This may suggest that repeated formation and downward deformation of ice-rich mantling on poleward-facing walls, which is interpreted to have been formed at high obliquity, result in the formation of thick ice-rich infilling. Poleward-facing slopes may be preferentially flattened by the ice-rich deposits rather than erosional modification.
