We are now in Moab, Utah and have spent the day at the magnificent Arches National Park where water and ice, extreme temperatures and underground salt movement are responsible for sculpting the landscape.

On clear, blue-sky days, like today, it is difficult to imagine such violent forces, or the 100 million years of erosion that have created this jaw-dropping vision that boasts one of the world’s greatest densities of naturally-created arches!

The arches are formed of Entrada Sandstone which was deposited in the area more than 150 million years ago. Over time it was buried by new layers, hardened into rock and shaped by the powerful forces of erosion.

A series of uplifts and collapses caused severe cracking in the 300-foot (91 metre) layer of buried Entrada Sandstone.

When overlying rock layers eroded away, the sandstone was exposed to weathering; cracks slowly widened and parallel rock walls were formed.

Rainwater continually dissolves the natural cement that holds sandstone together. This process combines with the pressure from water freezing in tiny cracks and causes the sandstone to flake and crumble. Eventually, enough rock falls out so that an opening is formed.

Turret Arch.

Arches known as Windows North and South.

This series of rock formations is known as Park Avenue as early park visitors thought that they looked like buildings of a big city!

Balanced Rock: the forces of erosion are sculpting more than just arches. The caprock of the hard Slick Rock Member of the Entrada Sandstone is perched on a pedestal of mudstone.