What is flysch and molasse?

In some parts of the world, windblown dust and silt blanket the land. This layer of fine, mineral-rich material is called loess.

Loess is mostly created by wind, but can also be formed by glaciers. When glaciers grind rocks to a fine powder, loess can form.
Streams carry the powder to the end of the glacier. This sediment becomes loess.

Loess ranges in thickness from a few centimeters to more than 91 meters (300 feet).
Unlike other soils, loess is pale and loosely packed. It crumbles easily;
in fact, the word “loess” comes from the German word for “loose.”
Loess is soft enough to carve, but strong enough to stand as sturdy walls.
In parts of China, residents build cave-like dwellings in thick loess cliffs.