The metalliferous deposits of Chile tend to be restricted to well denned metallogenetic provinces, each characterized by a dominant mineral or mineral assemblage. The most important ore deposits are those of copper, iron, silver, gold, and manganese. The primary minerals are few in number and most are simple sulfides and oxides; more complex sulfosalts are scarce. Secondary minerals in great variety are important constituents of the ores. Many of the ore deposits are situated along well defined structural lines, several hundred kilometers long, that parallel the structural grain of the Andes.The deposits, with few exceptions, are found in sedimentary or volcanic rocks that range in age from Jurassic to Late Cretaceous or in intrusive rocks of Late Jurassic to Late Cretaceous age. Most deposits are genetically related to intrusive bodies, which have an average composition within the range of granite-diorite.The metalliferous deposits can be classed as hydrothermal, sedimentary, contact-metasomatic and magmatic. Copper deposits are typically hydro-thermal, manganese deposits are sedimentary, and most of the iron ore deposits are contact-metasomatic. A unique group of iron ore deposits apparently formed by near-surface intrusion and surface flows of a magma consisting of iron oxides. Hydrothermal deposits, the most abundant and most important economically, were formed under conditions ranging from low to high temperature and pressure. © 1962 Society of Economic Geologists, Inc.
