The ancient Sumerians had Gods (plural).You can look at the longevity of the kings (kingship sent from heaven) of legend during antediluvian compared to post diluvian (Biblical patriarchs are said to have had long life spans).Sumeria in now Iraq goes back 6,000 years,and Gobleki Tepe in Turkey goes back 12,000 years.
http://en.wikipedia.org/wiki/Sumerian_kings_list (Wiki base reference only)
The presence of nanodiamonds (created by comet/meteor impacts) in the 11,000 ish B.C.E. soil layer suggests a North American comet/meteor impact.The near 2 mile thick ice sheet could have had lakes from black soot (volcanoes erupting elsewhere) settled on the surface absorbing solar heat.This impact causing water,and ice going everywhere must have looked like a flood of both water,and salt?Every pillar of the community would talk of this catastrophe for millenia to come,and the cities lost.
http://www.youtube.com/watch?v=f1GCgOI3B1o