Note 197 — Chapter XIII · THE ERUPTIONS OF LLANDEILO AND BALA AGE
Reading edition
Estimated at from 6000 to 7000 feet, Mem. Geol. Surv. vol. iii. 2nd edit. p. 131.
Reading edition
Estimated at from 6000 to 7000 feet, Mem. Geol. Surv. vol. iii. 2nd edit. p. 131.