Structural and petrophysical formation environments of porphyry copper stockworks

Structural and petrophysical environments of porphyry copper deposit formation are discussed. The paper analyzes deformation host environment effect on porphyry intrusion and breccia pipe morphology, form and structure of associated stockworks and metal ore grades. It is shown that major and giant deposit formation primarily depends on poorly permeable rocks, carbonate sequences suffering plastic deformation at high temperatures and pressure, present above ore-bearing intrusive, or basic and intermediate volcanogenic and intrusive lava facies and highly resilient and strong metamorphic rocks. The presence of such structural and petrophysical “screens” resulted in fluid plume emergence and extensive ore accumulation. Dolomites, limestones and Fe-rich basite assemblages hosted by these sequences also acted as geochemical barriers for hydrothermal solutions facilitating high-grade ore deposition.