Petrology and mineralogy of the Fenghuanshan granodiorite, Anhui Province, China: implications for petrogenesis and metallogenesis implication

The Fenghuangshan copper deposit, in the Tongling area of Anhui Province, China, is genetically associated with the Fenghuangshan granodiorite, which contains amphiboles that can be used to determine the pressure and temperature history of the magmas that formed this intrusion. Here, we investigate the petrography and mineralogy of the Fenghuangshan granodiorite, focusing on variations in amphibole composition and determining the conditions of amphibole crystallization. The data are used to determine the petrogenetic history and metallogenic significance of the hosting granodiorite. The amphiboles within the intrusion can be divided by texture into phenocryst, matrix, and poikilocrystal amphiboles. Electro model, combined with the barometry and thermometry and the stratigraphy of the study area, indicates that the Fenghuangshan copper deposit has not undergone any significant changes since its formation, thereby indicating that both the granodiorite and the associated mineralization are well preserved. This also suggests that the final depth of emplacement of the magma (3–6 km) represents the depth of formation of the associated copper deposit. This inference, combined with the fact that the current depth of exploration and mining in the study area is <1 km, indicates the great potential for discovering significant copper mineralization by deep exploration in this area.