Note 111 — Chapter XXXII · PERMIAN VOLCANOES OF ENGLAND

On the composition of the Devonshire breccias see Mr. R. N. Worth, Quart. Journ. Geol. Soc. vol. xlvi. (1890), p. 69. This author has adopted the view that the granite of Dartmoor represents the neck of a great volcano from which these later volcanic materials were ejected. But all the evidence seems to me in favour of numerous small vents situated not far from the outcrops of the lavas, as stated in the text. See Mr. B. Hobson, Quart. Journ. Geol. Soc. vol. xlviii. (1892), p. 498. The Dartmoor granite is later than the surrounding Carboniferous rocks, but no good evidence has been obtained to connect it with the Permian volcanic phenomena of Devonshire.