Gelderland push moraines: ice that pushed river deposits upwards
The Veluwezoom and the hills near Nijmegen are not wind-blown dunes. They are push moraines: frozen river deposits that the land ice pushed aside during the Saalian glaciation.
More than one hundred and fifty thousand years ago, Scandinavian ice advanced into the central Netherlands. In front of the ice lay sand and gravel that rivers had deposited earlier. These frozen layers fractured into slices and were tilted upwards. What you cycle over as a ‘mountain’ is that tilted stack. The Gelderse Vallei between them is the basin carved out by the ice.
On the Veluwezoom you can see the steep southern edge: the river later eroded it there. Near Nijmegen-Kleve, the same arc was cut through by the Rhine. That differs from the Utrechtse Heuvelrug, which forms a long ridge to the west, although the driving force was the same. Meltwater valleys cut into the flanks. During the following ice age, the land ice no longer reached the Netherlands, but wind and cold, dry conditions did; coversand and river dunes accumulated at the foot of the ridge.
Read the landscape from low to high. First clay or river, then coarse sand, then a view. A ridge like the Posbank is not a dune ridge. Dune sand was blown there. Push-moraine sand was pushed there.
Take a road that climbs from the low-lying land. The difference in elevation suddenly makes the ancient push moraine tangible: what looks like a line on a map, you can feel here in your legs.
A fresh perspective
The push moraines of the Veluwe and Utrechtse Heuvelrug embrace the same glacial basin: the Gelderse Vallei.
Compare a steep river-facing slope with a gentler inland flank of the same ridge.