Searches:Empty Quarter. Rub al-Khali, + geology, desertification, history,
I found on reference to desertification in wikipedia- that it used to be easier to get across the Empty Quarter. But nothing substantive. The geology hits talk about it's formation and the shifts in the humidity of the region in Precambrian times.
What I want to know is- has it always be sand seas, or has it changed in human history?
This is one of those questions that result from following too many links while doing research.