Base Metals Division - Aurora
The Aurora property is within the emerging Yauri-Andahuaylas metallogenic belt which hosts several large gold-copper-molybdenum porphyry deposits including Antapaccay and Los Chancas, as well as copper-skarn deposits Tintaya and Las Bambas.
Mineralization is centred on a complex, multiphase intrusion of granodiorite to quartz monzonite composition that may be of Oligocene age. Host rocks for the intrusion are hornfels and phyllites—metamorphosed sands and silts of Silurian age.The contact hornfels are andalusite-cordierite hornfels, and muscovite-cordierite-andalusite hornfels.Foliation in the metamorphic host rocks trends N60-70W and may have influenced control on shape of the stock and distribution of mineralization.
Primary mineralization consists of chalcopyrite, bornite, molybdenite with pyrite and pyrrhotite disseminated in altered porphyry and in quartz veinlets cutting the porphyries. Better grade mineralization appears to be associated with an increase in over-all sulfide content and with abundant silicification. Copper sulfides also are associated with abundant sericite alteration. Total sulfides generally are elevated, from three to five volume percent in mineralized porphyry. Presence of abundant phyllic alteration and apparent high pyrite to chalcopyrite ratio in drill core suggests that drill holes cut mainly pyrite-rich zone of the porphyry.