Mount Elden (foreground), sometime referred to as Elden Mountain, is an exogenous volcanic dome complex of the San Francisco volcanic field. Pleistocene-age lavas at Mount Elden are dacites - to be more precise, biotite-hornblende-hypersthene dacite. While largely an effusive vent complex, nearby pyroclastic flow deposits evince some explosive activity. For a geologic map and detailed rock unit descriptions, see Dick Holm's 'Geologic map of San Francisco Mountain, Elden Mountain, and Dry Lake Hills, Coconino County, Arizona (USGS Map I-1663). https://pubs.er.usgs.gov/publication/i1663
Photographer: Wayne Ranney
Photo Date: circa 2010