Summary
Highlights
Understanding rock types is important for activities like rock climbing, as seen at Red River Gorge's Corbin sandstone. Knowing about rocks also makes you sound knowledgeable when discussing natural formations like arches and canyons, even if your explanation isn't perfectly accurate.
Igneous rocks are formed from molten magma or lava. An example is new rock forming in Hawaii. When magma cools slowly, it produces large crystals, such as those observed in the Grand Tetons.
Sedimentary rocks are formed from the cemented parts of other rocks. You can often see the original grains. The Grand Canyon is a prime example, showcasing exposed sedimentary layers spanning millions of years and an active river depositing new sediment.
Metamorphic rocks are created when existing rocks are subjected to intense heat and pressure, causing them to twist and meld. A climbing spot in Golden, Colorado, provides an example of metamorphic rock that was originally granite, displaying a twisted, melded structure.
The rock cycle demonstrates how rocks continuously transform. Any rock type can break down into pieces to form sedimentary rocks, melt and cool to become igneous rocks, or undergo heat and pressure to become metamorphic rocks. This illustrates that almost any rock can become another kind of rock.