Kiwi ch(u)ck (note my clever impersonation of a kiwi accent), its an opal mining area at Coober Pedy in northern SA. This one puts a bit more perspective on it.
My understanding is that the little white piles of dirt are where they have put a drilling rig down to see what's there - and found nothing to get excited about. Where they have found something, there will be a mine shaft or more substantial digging.
Dr 