Note 116 — Chapter XXXII · PERMIAN VOLCANOES OF ENGLAND
Reading edition
The Coalbrookdale coal-field has been described by Sir Joseph Prestwich, Trans. Geol. Soc. (2) v. p. 428; and Prof. E. Hull, Quart. Jour. Geol. Soc. xxxiii. (1877), p. 629. The minute structure of the sill at Little Wenlock is referred to by Mr. Allport, op. cit. p. 550. The ground is mapped on Sheet 61 N.E. of the Geological Survey, and its structure is shown on Sheet 54 of the Horizontal Sections.