FIG. 4. Late Tertiary stratigraphy of southern Perú (Tosdal et al., 1981). Solid circles indicate the approximate locations of dated volcanic rocks, the ages of which are shown on the right (in Ma). Minerals dated: bi = biotite and pl = plagioclase. The K-Ar dates are from Tosdal et al. (1981). Relative positions of Moquegua landforms are indicated in the left-hand column. AdC = Altos de Camilaca, CdlC = Cerro de las Chulpas, CS = Cerro Sagollo, PL = Pampa Lagunas, PS = Pampa Sitana.