Mount Sanford lava flows (Pleistocene). Chiefly andesite flows from central shield of Sanford, shields (?) related to three subsidiary centers, and postulated Sanford caldera. Unit also includes domes, pyroclastic deposits, and a variety of shallow intrusive rocks that are exposed on south and southeast faces of Mount Sanford. Local accumulations of cinders, scoria, and bombs (stippled areas) indicate location of small parasitic vents. Lenses of light colored silicic air-fall tuff are also present.
Geologic map of the Gulkana A-1 Quadrangle, south-central Alaska