Note 117 — Chapter XXXII · PERMIAN VOLCANOES OF ENGLAND
Reading edition
Jukes, "South Staffordshire Coal-field," Mem. Geol. Surv. 2nd edit. (1859). The area is embraced in Sheet 62 N.W. and S.W. of the Geological Survey, and is illustrated in Sheets 23, 24 and 25 of the Horizontal Sections.