Final answer:
During continental collisions and mountain building, regional metamorphism is expected, which forms high-grade metamorphic rocks near the collision's center, becoming exposed through erosion.
Step-by-step explanation:
During continental collisions and mountain building, the type of metamorphism typically expected to occur is regional metamorphism. This process is driven by the intense pressure and heat generated as a result of the collision of tectonic plates. The pressure rearranges the minerals in rocks, potentially leading to foliation, while the heat may contribute to the recrystallization of minerals, producing new metamorphic rocks.
As part of the Barrovian sequence, the grade of metamorphic rocks increases closer to the center of the collision, reaching the highest grade at the center and then decreasing symmetrically on the opposite side. Moreover, these high-grade metamorphic rocks become exposed at the Earth's surface through the process of erosion, particularly in uplifting mountain belts.