Gneiss Formation:Gneiss is a metamorphic rock formed when existing rocks (igneous, sedimentary, or other metamorphic rocks) undergo significant heat and pressure, causing mineral recrystallization and the development of characteristic banding. Intrusions:The white and pink intrusions seen in the image are likely composed of minerals like feldspar or quartz, which have crystallized and formed layers or veins within the darker gneiss. Canadian Shield:Rocks similar to the one shown, with white and pink intrusions into gray gneiss, are characteristic of the Canadian (Precambrian, Laurentian) Shield, where they represent some of the oldest exposed rock formations. Metamorphism:The process of metamorphism can lead to the reorganization of minerals and chemical changes in rocks over long periods, resulting in new rock types with different physical and chemical properties.
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