When I was in Teotihuacan I meet a guide who show us the Mica layer. It was the 5th stage out of 7th. I saw it. He told me that all the city was covered with it. Not only the pyramide. I saw the layer on a house not pyramid. They dated the last layer not the first one. Who knows when they were built. I figure before the deluge. Do you know about Pangé the first continent. Is it possible that in that time all the people have the similar technologie. World existed before the bible.