Classifying Rocks by Formation
Learning Objective
I can classify rocks based on their formation.
Key Concepts
Igneous rocks are formed from hot molten rock that cools and solidifies from either magma or lava.
Extrusive igneous rocks form on the surface, cool quickly, and have small or no crystals, while intrusive rocks form inside the Earth, cool slowly, and have larger crystals.
Igneous rocks can be classified as either mafic, which are dark in color and contain magnesium and iron, or felsic, which are lighter and contain feldspar and silica.
Practice Questions
This lesson includes 3 practice questions to reinforce learning.
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1. Igneous rocks are classified based on their formation. What are the two main types of igneous rocks based on their formation environment?
2. Explain how the cooling rate affects the crystal size and texture of igneous rocks. Provide examples of rocks with different crystal sizes.
3. Describe the difference between mafic and felsic rocks in terms of their composition, color, and silica content.
Educational Video
All about Igneous Rocks
MooMooMath and Science