From: MYSTERIES OF ATLANTIS REVISITED. Edgar Evans Cayce et. al. Harper & Row Publishers, San Francisco, 1988, pp. 143-4
"The date 10,000 BC is central to the Cayce story of Atlantis and Egypt... the idea to Carbon date the pyramids originated from an A.R.E. group in Egypt in November 1982... Several A.R.E. members expressed an interest in putting the 10,000 BC date for the Great Pyramid to the test through Carbon-14 dating and agreed to finance the testing through the ECF (Edgar Cayce Foundation) if it could be done. Mark Lehner presented the idea... ECF agreed to sponsor the program at an estimated cost of $ 17,000... Retrieving of samples from as deep within the core of the Great Pyramid was ideal... Another possibility was mortar in the series of stress-relieving chambers above the King's Chamber..."