I've recently read a book by Dr Robert Scoch, Voyages Of The Pyramid Builders. Schoch is a geologist/geophysist and he is the one who dated the Sphinx at over 9,000 years old based on weathering patterns, etc.
He believes that a civilization existed on the Sunda Shelf (maybe Atlantis) in the Ice Age period and as their land sank below the waves at the end of the Ice Age, they spread out over the world taking their custom of pyramid building with them. He thinks the Sumerians were descendents of these people. It's a decent book. (The Sunda Shelf is the area around and including Indonesia)