Money Pit in cross section

The following image comes from the book Marvels and Mysteries of the Unexplained. It is a UK book and is the first place I read about Oak Island. The following image captured my imagination as a child, and even today I enjoy that same childlike wonder when looking at it.

money_pit_diagram

Image from Ed. Blundell, N. & Hall, A. Marvels and Mysteries of the Unexplained (1989) St. Michael P.36