How Are Rocks Made?

Video Transcript

"Hi I'm Jane Stammer from the Colorado School of Mines and I'm here to answer questions on how rocks are made. Depending on the type of rock you're interested in, they're made in different ways. Sedimentary rocks are made from the erosion and deposition of preexisting rocks. They are deposited in low lying areas either in a valley or a stream or in the sea and over time they accumulate different sediments and get buried and compacted and form rocks. Igneous rocks are formed both under the ground and above ground by pools of magma and when these magmas cool down, they crystallize and form minerals which later coalesce and form rocks. Finally metamorphic rocks are made deep under the ground at very high temperatures and pressures and preexisting rocks remelt, recrystallize and form new metamorphic rocks. And that is how rocks are made."