There are two Unit 4 GeoMations (animations) and three GeoClips (movies) linked below. We hope they help you understand and enjoy Unit 4.
In the text, you read about changes in subduction as North America neared and overran the spreading ridge in the Pacific, with the increasingly warm downgoing slab rubbing along the bottom of the continental lithosphere and squeezing and wrinkling the rocks far inland. The Front Range of the Rockies is the most dramatic evidence of the "wrinkling" from that squeezing, but many other ranges and smaller features have the same origin. All sorts of different shapes of folds and wrinkles are observed. One spectacular one, which few relatively few people visit, is the Waterpocket Fold in Capitol Reef National Park. The diagram here, from the Capitol Reef website of the National Park Service, shows the fold (of a type called a monocline, although you don't have to worry about memorizing fold types) both before and after erosion along the lovely Fremont River. You will see more of the fold with Kym Kline and Dave Janesko in the short video. (Note that the Park Service diagram and Dave-and-Kym’s demonstration are of the same thing, but viewed from opposite sides, so that Dave-and-Kym’s fold slopes down to your right and the Park Service’s slopes down to your left.)
CAUSE 2004 - Capitol Reef Monocline
Metamorphic rocks—those cooked and squeezed deep inside a mountain range—are often especially pretty. At the bottom of the Grand Canyon, you can see such rocks. They were formed long ago and many miles down, and then reached the surface as erosion removed the mountains above and the deep roots of those mountains floated upward. Later, these rocks were buried again under sediments from oceans, rivers and wind, and finally revealed to us as the Grand Canyon was carved by the Colorado River. Some people—including Dr. Alley—think that these rocks are so beautiful that they're worth the overnight hike into the canyon all by themselves!
Toothpaste Rocks / Grand Canyon National Park
The Great Smokies are geologically attached to the whole Appalachian mountain range, including the ridges near Penn State’s University Park campus. There, if you’re so inclined, you can visit the beach in the mountains—all thanks to Africa.