The Layer Cake

If this is cake it ain’t got a lot of fruit. At www.sciencedaily.com/releases/2010/08/100825185121.htm … research has found the North American continent is a layer cake (see Nature August 26th). Exploration of seismic factors at the interior of the earth illuminate how the continents formed. The continental land masses have been broken into pieces, joined back together, and then broken up again – but some old pieces of the lithosphere have existed over very long periods of time.