Scope and Contents Letter to Sir Archibald Geikie from Capt Clarence Edward Dutton telling him that he is undertaking field work in New Mexico. He is concentrating on the plateau country aided by good topographic maps of the region. He tells Geikie that there are landforms and cliffs similar to those in Utah and Arizona with exposures of Triassic, Permain and Cretaceous strata. These are overlain with evidence of volcanic activity, ancient basalt of 50-200 feet depth on the plateau. Young basalt, in vast lava...

Scope and Contents Letter to Sir Charles Lyell from Carlo Gemmellaro answering a list of questions that Lyell had evidently posed to him in a previous letter. Topics covered include volcanic strata, inaccuracies in maps of the area around Mount Etna drawn by Wolfgang Sartorius Von Waltershausen, and Lyell's theory that the 2 craters of Mount Etna were contemporary. Gemmellaro disputes this theory as each crater ejected different types of rock, Felspatic and Pyroxenic, with no mixing of the two. Gemmellaro...