Scope and Contents
Letter to Sir Archibald Geikie from Capt Clarence Edward Dutton discussing the fossiliferous Upper Cambrian metamorphosed sandstone shales found at Lake Superior and the Grand Canyon. At Lake Superior these beds overlie 1400 feet of unfossiliferous sandstone and shale, interspersed with layers of copper bearing metamorphosed volcanic ash. These are the same as the Huronian metamorphic beds at Lake Huron which are possibly of the Lower Cambrian age due to an unconformity (as identified by Alfred...
05 May 1883