FIG. 9: Porphyry copper deposits and major geological traits of the Andean belt. 1- Ocean trench. 2- Thick continental crust. 3- Paleozoic tecto-magmatic belts. 4- Andean magmatism. 5- Precambrian massifs. 6- Gravimetric contour lines. 7 to 12- Order of magnitude of ore deposits, expressed in metallic Cu content; 7: 50 M.t., 8: 20 M.t., 9: 5-10 M.t., 10: 2.5-5 M.t., 11: 1-2.5 M.t., 12: < 1 M.t.. 13- Paleozoic ore deposits. 14- Mesozoic and Cenozoic ore deposits. 15- Pampean Massif. 16- Patagonean Massif. 17- Limits of the Andean geosynclinal basin. 18- Limits of the Paleozoic geosynclinal basin. Slightly modified after Oyarzún and Frutos, 1980.