Médanos (geology)

For example, the médanos of La Pampa Province in Argentina are mostly vegetated dunes with occasional blowouts.

On the other hand, the dunes of Médanos de Coro National Park in Venezuela are mostly unvegetated.

The smaller and lighter ones move quickly forwards before the larger ones; but the latter soon overtake and crush them, whilst they are themselves shivered by the collision.

These medanos assume all sorts of extraordinary figures, and sometimes move along the plain in rows forming most intricate labyrinths, whereby what might otherwise be visible in the distance is withdrawn from the view of the traveller.

A plain often appears to be covered with a row of médanos, and some days afterwards it is again restored to its level and uniform aspect.