Note 93 — Chapter XI · TO HEKLA AND THE GEYSIR IN HAUKADALR.[87]
Reading edition
Mr Judd, examining Western Scotland, opines that the felspathic (acid) rocks have been erupted from the Eocene volcanoes, and the augitic (basic) from those of the Miocene age. In Iceland, however, both seem to have been discharged by the Post-tertiary, as well as by the Tertiary epochs.