Why are mineral deposits often found around the perimeter of igneous intrusions?

Mineral deposits are often found around the perimeter of igneous intrusions due to the process of hydrothermal alteration, where hot, mineral-rich fluids generated by the cooling magma migrate through fractures in the surrounding rock. As these fluids cool and react with the surrounding rocks, they can precipitate valuable minerals. Additionally, the temperature and pressure conditions around the intrusion create a favorable environment for the concentration of certain minerals, leading to the formation of ore deposits. This spatial relationship is commonly observed in various mining districts worldwide.