Rock Your Knowledge

What causes igneous rocks to form?

• Pressure

• Cooling magma and lava

• Compaction

• Cementation

Pumice has holes in it because . . .

• it cooled slowly underground.

• it cooled quickly above ground before the bubbles in the lava could burst.

• they were carved by the volcano.

• Worms crawl in and out of the rock, creating the holes.

Sandstone is a type of . . .

• igneous rock

• sedimentary rock

• metamorphic rock

• magma

If you were to go exploring and find basalt, you could infer that . . .

• There may have been magma in that area at some point in the past.

• It was once shale, but changed over time.

• Seashells built up in the area long ago.

• There may be fossils in the basalt.

Metamorphic rocks were once . . .

• igneous rocks that cooled too quickly.

• sedimentary rocks that were changed by time, heat, and pressure under the surface of the Earth.

• Seashells that sank to the bottom of the sea and were pressed together.

• Layers of mud and sand that built up over a long period of time.

What is the effect of squeezing and heating rock for a few million years?

• Nothing happens to the rock.

• It can turn into a new kind of rock.

• It will eventually push up through cracks in the Earth's surface.

• It will dissolve.

Sammy found limestone in the creek bed behind his house. What can Sammy infer about the creek bed?

• It was once a large volcano.

• He will probably find granite nearby.

• The creek bed was once at the bottom of the sea.

• The limestone was once sandstone, but turned into a new rock after being squeezed and heated for millions of years.

Shale is related to slate, as limestone is related to . . .

• Quartzite

• Marble

• Pumice

• Basalt

Which of the following people are using rocks?

• Bob is heating up his barbecue pit with coal.

• Susie is writing her name on the sidewalk with chalk.

• Ann and John are making a border around their garden with bricks.

• They are all using rocks.

Based on what you know about the different kinds of rock, you can infer that the word morph in metamorphic means . . .

• same

• different

• change

• heat