Supporters of the subglacial volcanism origin hypothesis note that the Ganges Mensa's horizontally-oriented cap rock is morphologically consistent with the cap rock seen in tuyas in the Azas Plateau. Various domes and arcuate ridges have been observed across the cap rock of Ganges Mensa, leading some to speculate that these likely volcanic landforms are actually evidences of magmatic dikes, volcanic vents, or the erosional remnants of volcanic necks that may have intruded underlying layers to deposit the cap rock.