basalt layering and flood deposits

As well as being somewhat out of date (late 19th century), Donelly was, I am afraid, something of a crank.

Donnelly also wrote a book on Atlantis (as a real place) and argued that Francis Bacon was the author of Shakespeare's pkays based on the prexence of "codes" in the works. Of course these "codes" rested on rather arbitrary manipulations of the text - which could equally well produce quite different "messages". As his critics at the time showed.