The carboniferous formation is the chief repository of coal in Britain.
"Geology"
James Geikie
Here and there we found pieces of lignite coal, and as we neared Svartevoeg the carboniferous formation became more evident.
"My Attainment of the Pole"
Frederick A. Cook
So again, in his famous lecture on Coal, Professor Huxley depicts what might have been the reflections of a giant reptile of the carboniferous Epoch, suggested by the seemingly senseless waste of nature's powers in the production of the primeval forests, that have furnished the coal measures, to which so much of our progress and civilization is directly due.
"The Old Riddle and the Newest Answer"
John Gerard