Everybody has seen those “B” movies where an explorer (usually in the jungle) steps into an innocent-looking pool, and finds himself sinking into soft sand and water. No matter how he struggles, he sinks…usually the scene ends with a hand held up, sinking into the swamp. I’ve always wondered-is this stuff (quicksand) for real? Do people really sink like a stone into it? And, where do you usually find it?
I had little idea about it myself, but the following link does a good job of explaining all you ask about.
In brief, it is sand saturated with water rising from below. It is rarely more than a few feet deep. You do not sink into it unless you struggle, in which case you dig yourself into it (ironic, no?). Basically, it forms near water, so don’t expect much in the desert.