How rocks change from one kind to another
Grade 6 Science Worksheet
Circle the best answer.
Bo compares two igneous rocks. Granite has large crystals; basalt has tiny ones. Which one cooled slowly, deep underground?
- Granite, because pressure squeezed its crystals big
- Granite, because slow cooling grows large crystals
- Basalt, because slow cooling makes tiny crystals
- Basalt, because darker rock cools more slowly
Obsidian looks like smooth black glass, with no crystals Esme can see. What does that show about how it formed?
- Layers of sand were pressed together
- Heat and pressure changed it without melting
- Lava cooled so fast that crystals could not grow
- It cooled very slowly, deep underground
Jun drops a light, bubbly rock called pumice into water, and it floats. It formed from frothy lava that cooled very quickly. What are its crystals like?
- Large, because gas holes make room to grow
- Tiny or none, because it cooled fast
- Lined up in layers, like sedimentary rock
- Large, because it cooled fast
A metamorphic rock deep underground gets so hot that it melts, then cools again. What does Milo say it becomes?
- A sedimentary rock
- Nothing; metamorphic rock is the last step
- An igneous rock
- A new metamorphic rock
Noah finds a rock with flat layers and a leaf fossil pressed between them. Which clue points to sedimentary rock?
- It must have melted to hold a leaf
- It was squeezed into wavy bands
- Its color is gray
- Layers holding a fossil
Pia sees a rock with light and dark minerals lined up in wavy bands that formed under great pressure. Which type of rock is it?
- Lava rock full of gas holes
- Igneous, because it melted into bands
- Metamorphic, from heat and pressure
- Sedimentary, because bands are sand layers
Near an old volcano, Ren finds a dark rock full of small holes left by gas bubbles. Which story fits the clues?
- Sand grains were pressed and cemented
- Magma cooled slowly and grew big crystals
- Heat and pressure squeezed it underground
- Lava cooled fast at the surface, trapping gas
Can a sedimentary rock become an igneous rock? Tala checks the rock-cycle diagram. Which answer is right?
- Yes, if it melts into magma and then cools
- Yes, if it is pressed and cemented again
- No; it has to become metamorphic first
- No; sedimentary rock just wears away
A metamorphic rock is lifted up to the surface by moving rock. What could happen to it next, by Zee's diagram?
Use the picture in question 8.
- It must melt before it can change again
- It turns straight into igneous rock in the air
- It could weather into sediment and become sedimentary rock
- It stays exactly the same at the surface
“Rock-cycle diagram with an arrow from” Granite gets buried deep in a mountain range and is heated and squeezed, but it does not melt. What does Ari say it becomes?
- Magma
- Sedimentary rock
- Metamorphic rock, such as gneiss
- Nothing, since igneous rock cannot change
