An Early Geological Map of Ireland: A Collaboration of Richard John Griffith and George Bellas Greenough

Abstract: In the second decade of the 1800s Richard John Griffith was preparing a geological map of Ireland. This was to finally be published in 1838 on a small scale with a larger quarter-inch map appearing in the following year. Recently, a water-coloured manuscript geological map of Ireland has been located in the George Bellas Greenough collection of the Geological Society of London. It represents a collaborative trans-Irish Sea effort between Griffith and Greenough to display Ireland’s geological structure, and probably dates from 1814. On a copy of Alexander Taylor’s 1793 map of Ireland Greenough provided marginal notes, delineated some geological boundaries with particular attention paid to County Donegal, and provided the names of nine lithological types in no apparent stratigraphic order. He then sent the otherwise blank map to Griffith, who applied the watercolour wash to show the distribution of those lithologies, before he returned the map to London. This manuscript geological map of Ireland may pre-date that attributed to Alexander Nimmo, which dates from no later than 1822.