looking glass rock
As blocks of continental crust rode across one another, some rocks became so hot that they melted. Molten rock at the Earth's surface erupts to form either volcanoes or quiet lava flows. When molten remains deep below ground, it cools crystallizes to form bodies of rock that is called igneous plutons. Plutons are scattered throughout the Southern Appalachians like plums in a pudding. Some plutons are now exposed at the land surface due to erosion of overlying rock; they weather to form unusual, smooth-sided domes like Looking Glass Rock, south of Asheville, North Carolina. The plutons are composed of granite and similar rocks.