Instructions
Read the information below about the three main types of rocks: igneous, sedimentary, and metamorphic. Then, answer the questions that follow.
Types of Rocks
There are three main types of rocks:
- Igneous Rocks: These rocks are formed from molten magma or lava. When magma cools and solidifies beneath the Earth’s surface, it creates intrusive igneous rocks (like granite). When lava cools and solidifies on the surface, it creates extrusive igneous rocks (like basalt).
- Sedimentary Rocks: These rocks are formed from the accumulation of sediments. Over time, sediments are compacted and cemented together. Common sedimentary rocks include sandstone, limestone, and shale. They often contain fossils and are usually laid down in layers.
- Metamorphic Rocks: These rocks are formed from existing rocks that are changed due to heat, pressure, or chemical processes. Examples include schist and marble. Metamorphic rocks often have a layered or banded appearance due to the alignment of mineral grains.
Questions
- Describe how igneous rocks are formed.
- What are sedimentary rocks mostly made of, and how are they formed?
- Explain the process that leads to the formation of metamorphic rocks.
- Name two examples of igneous rocks and two examples of sedimentary rocks.
- Which type of rock often contains fossils? Why?
- List one way that metamorphic rocks are different from igneous rocks.