The presence of snail shells on a high-rise plateau suggests that the plateau was once at a lower elevation, and has since been uplifted. Snails are terrestrial gastropods, meaning that they live on land and breathe air. They are unable to survive underwater, so their presence on the plateau indicates that it was once dry land. The uplift of the plateau would have caused the snails to become extinct, as they would have been unable to adapt to the new environment. The snail shells that are found on the plateau are therefore a reminder of its past geological history.