The origin of hypogene alteration and mineralization features in the Escondida porphyry Cu deposit resulted from intense overprinting related to three main hydrothermal stages. The beginning of each stage is recorded by deposition of bright quartz crystals on vein walls that precipitated from high-temperature fluids. In the deepest zones of the deposit, the earliest stage started with exsolution of intermediate-density fluids, which transported high concentrations of Cu, whereas Mo was not detected. However, in the shallow zones, the early stage began with depressurization and unmixing of intermediate-density fluids, which generated both a hypersaline and vapour-rich fluid phase, producing an important geochemical segregation between both phases. The transitional stage also started with circulation of intermediate-density fluids but never experienced unmixing. These fluids transported the highest Mo concentrations in the deposit; however, Cu displays lower concentrations relative to intermediate-density fluids from the early stage. The beginning of the late stage was also associated with intermediate-density fluids; however, Cu and Mo were below the detection limits in most of the analysed fluids. During the evolution of the three stages, the fluids experienced gradual cooling, which promoted the precipitation of euhedral and zoned quartz crystals that overgrew the early high-luminescence quartz generations. Sometimes, sulfide minerals display euhedral crystal boundaries with zoned quartz, suggesting that mineralization started during these phases. The latest events detected in each main stage are linked to cooler and low-salinity fluids, from which dark quartz and hypogene sulfides precipitated along microfractures and interstitial spaces developed in the earlier quartz generations.

Escondida 斑岩铜矿床的下成因蚀变和矿化特征的起源是由与三个主要热液阶段相关的强烈叠印引起的。每个阶段的开始都是通过在高温流体沉淀的脉壁上沉积明亮的石英晶体来记录的。在矿床最深的区域，最早的阶段开始于中等密度流体的出溶，这些流体输送了高浓度的 Cu，而没有检测到 Mo。然而，在浅层，早期阶段开始于中密度流体的降压和解混，产生了高盐度和富蒸汽的流体相，在两相之间产生了重要的地球化学分离。过渡阶段也开始于中等密度流体的循环，但从未经历过分离。这些流体输送了矿床中最高的 Mo 浓度；然而，相对于早期的中等密度流体，Cu 显示出较低的浓度。晚期的开始也与中等密度流体有关；然而，在大多数分析的流体中，Cu 和 Mo 均低于检测限。在这三个阶段的演化过程中，流体经历了逐渐冷却，促进了自形和分带石英晶体的沉淀，这些晶体过度生长了早期的高发光石英世代。有时，硫化物矿物显示出带分带的石英的自形晶界，表明在这些阶段开始矿化。