Flames can displace and transmute earth into ash (another form of earth), but only seldom obliterate it (bombs don't count. they're man made, not elemental
) . Floods can erode earth.. but when the water evaporates what's left over? Wind can weather earth, but only very, very slowly(talking about stone).
Very good points, grasshopper, but for each one could make a counterpoint. ^_^