Earth Science: Types of Rocks: Igneous, Sedimentary, Metamorphic
Classifying rocks by how they form
Earth Science: Types of Rocks: Igneous, Sedimentary, Metamorphic
Classifying rocks by how they form
Earth Science - Grade 4-5
- 1
A rock forms when melted rock cools and hardens. What type of rock is it?
Think of magma or lava cooling into solid rock.
It is an igneous rock because igneous rocks form when melted rock cools and hardens. - 2
Sand, mud, and small rock pieces settle in layers at the bottom of a lake. Over a long time, the layers are pressed and cemented together. What type of rock forms?
A sedimentary rock forms because sedimentary rocks are made from layers of sediment that are pressed and cemented together. - 3
A rock is changed by heat and pressure deep inside Earth, but it does not melt. What type of rock is it?
The word metamorphic means changed form.
It is a metamorphic rock because metamorphic rocks form when existing rocks are changed by heat and pressure without melting. - 4
Circle the rock that is most likely igneous: granite, sandstone, or marble. Explain your choice.
Granite is most likely igneous because it forms when magma cools and hardens underground. - 5
A student finds a rock with many thin, flat layers and tiny pieces of shell inside. Which rock type is it most likely to be?
Fossils are most often found in rocks that form from layers of sediment.
It is most likely a sedimentary rock because sedimentary rocks often have layers and may contain fossils or shell pieces. - 6
Complete the sentence: Igneous rocks can form from magma below Earth's surface or from lava on Earth's surface.
Igneous rocks can form from magma below Earth's surface or from lava on Earth's surface because both are melted rock that can cool and harden. - 7
Explain one way sedimentary rocks and metamorphic rocks are different.
Compare how each rock type begins and what changes it.
Sedimentary rocks form from layers of sediment, while metamorphic rocks form when existing rocks are changed by heat and pressure. - 8
Pumice is a rock with many holes that can form when lava cools quickly with gas bubbles trapped inside. What type of rock is pumice?
Pumice is an igneous rock because it forms from cooling lava. - 9
Limestone can form from the remains of ocean animals, such as shells, that build up and harden over time. What type of rock is limestone?
Think about shells and sediments collecting on the ocean floor.
Limestone is a sedimentary rock because it forms from materials that collect in layers and harden over time. - 10
Marble forms when limestone is changed by heat and pressure. What type of rock is marble?
Marble is a metamorphic rock because it forms when limestone is changed by heat and pressure. - 11
Look at this rock cycle situation: A sedimentary rock is buried deep underground. Heat and pressure change it into a new rock. Name the new rock type and explain what happened.
The rock changed form, but it did not melt.
The new rock type is metamorphic rock. The sedimentary rock was changed by heat and pressure while it stayed solid. - 12
Which rock type is most likely to contain fossils: igneous, sedimentary, or metamorphic? Explain why.
Sedimentary rock is most likely to contain fossils because sediments can cover and protect plant and animal remains as layers build up. - 13
A rock has ribbon-like bands of light and dark minerals. It formed when another rock was squeezed and heated. What type of rock is it most likely to be?
Heat and pressure can make minerals line up in bands.
It is most likely a metamorphic rock because bands can form when minerals are changed and squeezed by heat and pressure. - 14
Sort these rocks into the correct groups: basalt, sandstone, slate. Write igneous, sedimentary, or metamorphic next to each rock.
Basalt is igneous because it forms from cooled lava. Sandstone is sedimentary because it forms from cemented sand grains. Slate is metamorphic because it forms when shale is changed by heat and pressure. - 15
Write one example of each rock type and describe how each one forms: igneous, sedimentary, and metamorphic.
Use examples from the worksheet if you need help.
One possible answer is granite for igneous because it forms when magma cools, sandstone for sedimentary because it forms from cemented sand, and marble for metamorphic because it forms when limestone is changed by heat and pressure.