15 Questions
What is the definition of igneous rocks?
Rocks formed when magma cools and crystallizes or solidifies
What is the meaning of the word 'igneous'?
Fire
What is the process where a solid of highly organized atoms or molecules are formed into a solid structure known as a crystal?
Crystallization
What determines the type of crystals formed in igneous rocks?
The atoms and molecules contained in the magma
What are the two types of igneous rocks?
Intrusive igneous rocks and extrusive igneous rocks
Where do igneous rocks form when magma cools?
At the surface of a volcano or while still inside Earth's crust
What is magma?
Molten rock under Earth's surface
What type of rock is granite?
Intrusive
What causes the formation of obsidian?
Rapid cooling of lava
What type of texture does pumice exhibit?
Glassy
Which type of rock is characterized by a bubbly texture?
Pumice
What mineral content classification do gabbro and basalt fall under?
Mafic
What is the silica content in felsic rocks?
More than 65%
What cooling process results in a porphyritic texture?
Slow cooling
What is the main factor determining the texture of igneous rocks?
Cooling rate
Study Notes
Igneous Rocks
- Igneous rocks are rocks that are formed from the cooling and solidification of magma or lava.
- The word 'igneous' comes from the Latin word 'ignis', meaning fire.
Crystal Formation
- Crystallization is the process where a solid of highly organized atoms or molecules are formed into a solid structure known as a crystal.
- The rate of cooling determines the type of crystals formed in igneous rocks.
Types of Igneous Rocks
- There are two main types of igneous rocks: intrusive and extrusive.
- Intrusive rocks form when magma cools beneath the Earth's surface.
- Extrusive rocks form when lava cools above the Earth's surface.
Magma
- Magma is a mixture of molten rock, gas, and minerals that forms beneath the Earth's surface.
Rock Types
- Granite is a type of felsic rock.
- Obsidian is formed when lava cools rapidly, resulting in a glassy texture.
- Pumice exhibits a porous texture due to the rapid cooling of lava.
Texture
- Rocks with a bubbly texture are characteristic of pumice.
- The rate of cooling is the main factor determining the texture of igneous rocks.
- Porphyritic texture is formed when magma cools slowly, resulting in a mixture of large and small crystals.
Mineral Content
- Gabbro and basalt fall under the mafic mineral content classification.
- Felsic rocks have a high silica content, typically above 65%.
Test your knowledge of igneous rocks with this quiz. Explore the formation, characteristics, and types of igneous rocks, and learn about their significance in the rock cycle.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
