FIG. 8. (a). Simplified topographic map of the Quellaveco prospect area, showing locations of dated ignimbrite flows on the northern flank of the Río Asana valley. The northwest-southeast (A-A') line indicates the approximate location of the cross section. (b). Schematic northwest-southeast cross section along the axis of the Quellaveco orebody, illustrating the interrelationships of present topography, dated Miocene ash-flow tuffs, inferred Pampa Sitana terrace pediment, and the Quellaveco sulfide enrichment zone (modified after Clark et al., 1990b). Vertical scale is exaggerated.