Koen's point about how the dunes are formed by wind is a good one.
Different materials have different ways of eroding or shaping themselves depending on whether they are acted upon by wind, water, gritty materials, or time. Not every kind of material (or composite) can shape itself into specific curves or layers like those in the VMS. There are characteristic shapes and patterns that help geologists identify and date the various kinds of materials and layers.
The ones that form into curved peaks or helical shapes tend to be softer materials like sand and sandstone (as illustrated by the links above). Even more specific shapes are dependent on whether it's a build-up or break-down process.
Different materials have different ways of eroding or shaping themselves depending on whether they are acted upon by wind, water, gritty materials, or time. Not every kind of material (or composite) can shape itself into specific curves or layers like those in the VMS. There are characteristic shapes and patterns that help geologists identify and date the various kinds of materials and layers.
The ones that form into curved peaks or helical shapes tend to be softer materials like sand and sandstone (as illustrated by the links above). Even more specific shapes are dependent on whether it's a build-up or break-down process.
