The Chiwawu copper-molybdenum-tungsten deposit in northern Taihang Mountains: Petrogeochemistry, Sr-Nd-Pb isotopic characteristics and geological implication

The Chiwawu Cu-Mo-W deposit, occurred in the central facies porphyritic granodiorite of Chiwawu rock mass, is a typical porphyry deposit in northern Taihang Mountains, belonging to the high-K calc-alkaline series. With the decrease of σ value, the content of SiO₂ increases. The oxides such as CaO, MgO, Fe₂O₃, TiO₂, and P₂O₅ are negatively correlated with the SiO₂ content, showing the characteristics of quasi-aluminous calc-alkaline I-type granite. Elements of Rb, Ba, Th, U, La, and Nb are relatively depleted, with a slightly positive Eu anomaly. The ⁸⁷Sr/⁸⁶Sr ratio of Chiwawu rock mass is averagely 0.7068, with the initial ratio ε_Nd(t) of -20.9 to -16.1, the ²⁰⁶Pb/²⁰⁴Pb ratio of 16.5, the ²⁰⁷Pb/²⁰⁴Pb ratio of 15.2 and the ²⁰⁸Pb/²⁰⁴Pb ratio of 36.8, indicating that the magma is primarily derived from the lower crust mixed with minor mantle materials. Combined with the regional geological background, it is concluded that under the influence of subduction of Paleo-Pacific Plate, the large-scale remelting of lower crust and upper mantle materials occur in North China Craton, leading to the upward invasion along the deep fault zone of Taihang Mountains, eventually forming the Chiwawu Cu-Mo-W deposit. The Chiwawu rock mass and magmatic rock belt in northern Taihang Mountains are promising targets for future mineral exploration.