New metallogenic approaches to the Coastal Batholith, Arequipa segment between 15° and 16°30' South latitude, Peru

The mapping of intrusive rocks from the Arequipa segment of the Coastal Batholith was complemented by detailed petrographic studies and U-Pb zircon ages. The results were analyzed and grouped into seven stages and four cycles. Each stage shows unique magmatic volumes, and the landform finds expression in batholiths and stocks. Cycles Ⅰ and Ⅱ represent the stages of Jurassic magmatism (201~145Ma), the magmatic differentiation grades from gabbros to granites. Cycles Ⅲ and Ⅳ represent the stages of Cretaceous magmatism, the magmatic differentiation varies from tonalites to monzogranites, diorites to granodiorites and from tonalites to granodiorites. In relation to the amphibole and biotite crystal population, the intrusives of the Cycle Ⅰ have abundant pyroxene and amphibole crystals, associated with Au-Fe mineralization; those of Cycle Ⅱ have abundant clustered amphibole crystals and in some cases are aligned or grouped biotite crystals and eventually hexagonal, associated with Cu-Au-Fe mineralization; those of Cycle Ⅲ have well developed isolated amphibole and biotites, and the intrusive rocks are associated with Au-Cu and Fe; those of Cycle Ⅳ have some amphibole and hexagonal biotite in separated form, and the intrusive rocks are more felsic and are associated with Cu-ZnAu-Ag-Fe and Cu-Au-Mo mineralization.