Yet more interesting dirt facts.
What an alluvial fan looks like after it is recaptured and returned to its cell.
Definition 1. A pile of dirt in the desert.
These occur everywhere that dirt has escaped from the hills and gotten out into the wide open spaces where it can live free. Or so it thinks. Mainly, it's out there for you to step in. As if you needed that.
Definition 2. A pile of desert dirt that has been flattened and spread out in a fan shape over the centuries.
It gets this particular shape by being run down every decade or two by panicked water rushing to get out of the hills as fast as it can. (Water is afraid of heights.)
Definition 3. The pleasant, cool and welcome nighttime breeze flowing down out of the desert hills and through your campsite after dark just before the rainstorm, and the flood, and your sudden, unpleasant death.