Earth+Materials

Rock Cycle This may seem hard to believe, but rocks go through a cycle of change and renewal. We call it the rock cycle. It goes something like this: magma flows deep inside the Earth. It erupts as lava from a volcano. It cools and becomes igneous rock. Weathering and erosion break the igneous rock down and carry away the sediment. The sediment is deposited in layers, building up over the years. Pressure changes it to sedimentary rock. (Sedimentary rock can also erode and weather, returning to sediment again.) Sedimentary rock gets pressed deeper into the Earth. It changes into metamorphic rock. (Metamorphic rock, if it comes to the surface, can also erode and weather away.) It gets pressed still deeper into the Earth. Heat and pressure cause the rock to melt. It is magma once again, and the cycle continues.

"The Rock Cycle" is a song about two interrelated subjects. First, it is about the theory of "plate tectonics". This theory explains that Earth's crust

is made up of many plates, which float on the molten rock beneath them. There are cracks, or faults, where these plates meet and here earthquakes and volcanoes often appear when the plates move.

The second related topic in this song is, of course, where it gets its name. The lyrics explain how rocks are formed, and identify the three different types of rocks (igneous, sedimentary, and metamorphic) and differences in how each type is formed. Voilá - the Rock Cycle!!

**Now Plate Tectonics is the theory**

**That crust is movin' under me**

**Continents they drift apart**

**'Cause molten rock is in Earth's heart**

**Scientists say there are three ways**

**That plates can move around these days**

**Convergent, Divergent, and Transform-Fault**

**Is what this rumbling's all about**

**Chorus:**

**Let it rock! the rock cycle**

**Let it rock! the rock cycle**

**The rock cycle, the rock cycle, let it rock!**

**Two hundred million years ago**

**Pangaea was the land below**

**Continents they drift apart**

**Heat and pressure is the start**

**Check the seismograph it shakes!**

**Plates are moving - EARTHQUAKES!**

**Rumble underground below**

**Better run, she's gonna BLOW!**

**Chorus**

**Now magma pushes through the crust**

**And when it cools it's Igneous**

**The next in line is elementary**

**Weathering makes it Sedimentary**

**Then heat and pressure make rocks change**

**The stuff inside can rearrange**

**The final rock, you can't ignore it,**

**Yeah, you know, it's Metamorphic!**

**Chorus**