Do large impact basins in the Southern Hemisphere of Mars control the distribution of polar structures and deposits?

Among the problems in Martian geology are the cause of the off-axis and asymmetric distribution of the southern polar layered terrain and residual ice deposits and the cause of the orientation of scarps, valleys, and reentrant canyons that occur. A problem region is the small number of large (D greater than 500) impact basins seen in the relatively well preserved cratered terrain of the south polar region. This region was mapped in detail, searching for evidence of ancient, highly degraded impact basins for two reasons: To determine whether the apparent absence of large impact basins is due to incomplete mapping and recognition or a fundamental characteristic of the Martian crust related to the origin of the Martian crustal dichotomy, and whether ancient impact basins exert some control on the distribution of volcanic and polar deposits in the Southern Hemisphere and on the topography on which these deposits lie. The possible influence is examined of the candidate basins in localizing the asymmetric distribution of polar deposits and in controlling the orientation of structures found within these deposits.