I have a geography question. Just why do they call the area between Memphis and Vicksburg the Delta? There is some blues info here. But I always thought a delta was where a river ran into a larger body of water, like the Mississippi River at New Orleans. I'm currently reading a book, North Toward Home whose author, Willie Morris, was from Yazoo City. In it he talks a little about the "floor of the sea" and the "primordial forests." Amybody know what this means?