Source: Edward. “Geology Rocks: The Rock Cycle.” Educational Resources K12 Learning, Physical Science, Science Lesson Plans, Activities, Experiments, Homeschool Help, www.elephango.com/index.cfm/pg/k12learning/lcid/11103/Geology_Rocks:_The_Rock_Cycle.
This is a video from youtube, describing what the rock cycle is all about. Students can visually see the different kinds of rocks that are apart of the rock cycle.
This text is excerpted from an original work of the Core Knowledge Foundation.
Rocks you see in the world around you might seem like permanent fixtures. Given enough time, however, all rocks change. They are created, destroyed, and recreated in a continuous cycle. Geologists call this ongoing process the rock cycle.
The rock cycle has no starting or ending point. You can jump in anywhere to see how it works. Let’s begin with magma erupting from a towering volcano. The magma (now lava) cools and hardens into igneous rock. Over the course of thousands of years, sun, wind, rain, and freezing temperatures cause the rock to weather, or break down into smaller pieces. The pieces continue to weather, slowly breaking down into sediments. Howling winds, flowing water, and gravity gradually move the sediments down the sides of the volcano and beyond. Movement of sediments from place to place is called erosion.
Imagine that the sediments end up in a lake, where they settle to the bottom. Over long periods of time, more layers of sediments are deposited on top of them. Compacting and cementing processes eventually turn the deeply buried sediments into sedimentary rock.
Now imagine that the sedimentary rock is near the edge of a tectonic plate. The plate collides with another plate—very slowly, of course. Tremendous heat and pressure generated by the collision gradually turn the sedimentary rock into metamorphic rock. As the plates continue colliding, their rocky edges crumple. The metamorphic rock is slowly pushed up higher onto Earth’s surface. Think mountains! Exposed to air, rain, and snow, the rock begins to weather and erode.
Alternatively, one tectonic plate might be sliding beneath another. The metamorphic rock along the edge of the descending plate gets hotter and hotter as it nears the mantle. At some point it melts into magma—magma that someday might erupt from a volcano again.
Understanding how rocks change helps geologists understand how Earth has changed over time
Source: “The Rock Cycle.” ReadWorks, www.readworks.org/article/The-Rock-Cycle/18512bfe-311e-4374-84a4-383a17aa1713#!articleTab:content/.
