岩浆熔融体性质及演化在成矿过程中的作用——以西藏玉龙斑岩铜(钼)矿床为例

The nature and evolution of magmatic melts in mineralization: An example from the Yulong porphyry copper (molybdenum) deposit, Xizang

玉龙斑岩铜 (钼 )矿床是亚洲最大的斑岩型铜矿床 ,包含多种矿化类型 ,成矿作用复杂。作为典型的斑岩型矿床 ,岩浆熔融体的性质在玉龙铜矿床的形成过程中起到了至关重要的作用。本文将分别从岩浆熔融体的物理和化学性质出发 ,解释玉龙矿床为何能成为玉龙成矿带中唯一一个超大型矿床的原因。在熔体演化方面 ,笔者主要通过对熔体密度、粘度的计算获得有关数据 ,以了解熔体运移、含矿流体分离的过程 。

The Yulong porphyry copper (molybdenum) deposit in Xizang is the largest one in China and even in Asia. As a representative supergiant porphyry copper deposit comprising varying mineralization types, the nature of magmatic melts may play the most important part in the mineralization of the Yulong copper deposit. The study of physical and chemical properties and evolution of the magmatic melts was made on the basis of the calculated data on the density and viscosity of the magmatic melts to explain the formation of the Yulong copper deposit. Abundant ore forming elements and volatile components (mineralizers) in the magmas from which the Yulong copper deposit may serve as the principal sources of the ore forming matter in the deposit. The viscosity (56.43 Pa·s) and density (2.09g/cm 3) of the magmatic melts suggest a kind of low viscosity and high density of magmas. The physical and chemical properties of the magmas facilitate the enrichment of ore forming matter and the generation of abundant mineralizing fluids.