FIG. 2. Summary of previously proposed landform and supergene chronologies in northern Chile and southern Perú. References for northern Chile: A.H. Clark, unpub. short course notes for Rio Tinto Mining and Exploration Ltd.: Mendoza (1999), Nishiizumi et al. (1998), Mortimer (1973), Sillitoe et al. (1968), and Clark et al. (1967a-b), and for southern Peru: Tosdal (1978), Tosdal et al. (1981, 1984), and Clark et al. (1990b)