Some scanning on google earth shows a vast area of the Nevada desert, about 100km NW of Las Vegas, dotted with craters. These are scars from the Nevada Test Site, established for the testing of nuclear devices in 1951.
The Sedan Crater, measuring 390m x 100m (less than half the diameter of the hole I am creating), has even been listed on the National Register of Historic Places – over 10,000 people visit it each year. It can supposedly be seen from earth with unaided eye. The craters also have similar features to the topography of the moon so American astronauts train here before missions.
I won’t be using nuclear explosions to create my hole, but it does give a good indicator to how the sand holds once excavated, and perhaps my somewhat romanticised idea of the strata and rock needs a bit of a rethink (different kinds of polishing?)