Click on image to view larger version.
Fig. 16. Structure contour and isopach map for the Otowi Member of the Bandelier Tuff. Structure contours are for base of Guaje Pumice Bed and show the paleotopography before eruption of the Otowi Member. Otowi ash-flow tuffs filled a broad north-trending paleovalley bound by the Sierra de los Valles highlands on the west and the Cerros del Rio basaltic highland on the east. The variable thickness of the Otowi Member on the western side of the plateau represents deep erosion of these poorly consolidated nonwelded tuffs before eruption of the Tshirege Member.
