Well I wish somebody would acknowledge the strangeness. It's hard to put into words any better than I have done already, but some honest contemplation of the facts should make it apparent. There is just no way to rationally explain how discreet time periods over the history of the earth got marked by clearcut sediment depositions that start at the beginning of the period and end at the end of it.
Well, they don't do that...
As many of us have said, there are a number of unconformities in the GC record.