The geology of the Viking Lander 2 site

Abstract

Viking Lander 2 landed on a flat plain of fine-grained sediment overlain by dispersed, evenly distributed boulders. The fine-grained material is probably part of a high-latitude mantle comprising material swept south from the polar regions. The boulders, which have distinctive deep pits, or vesicles, may be the residue of an ejecta deposit from the crater Mie. Alternatively, they may be the remnants of lava flows which formerly covered the region. Polygonal sediment-filled cracks may have been formed by ice wedging, similar to the process that occurs in terrestrial permafrost regions. Alternatively, they may be desiccation polygons.