Igneous intrusion

High school (ages 12+)
Environment & Earth

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Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/igneous-intrusion

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the rock texture?Typically phaneritic due to slow subterranean cooling, allowing large crystal growth
2. What is the classification basis?Mineralogical composition, particularly quartz, feldspar (alkali and plagioclase), and feldspathoid content
3. What are igneous intrusions?They are bodies of melted rock that cool slowly deep inside the Earth's crust. Because they cool so slowly, the crystals grow big enough to see with the naked eye.
4. Why do intrusive rocks have big crystals?The slow cooling deep underground gives ions time to move and line up into large, interlocking crystals. This makes the rock look like a big puzzle of visible grains.

Phaneritic: An igneous rock texture characterized by large, visible mineral crystals formed by slow cooling.
Country Rock: The pre-existing rock formations into which magma intrudes and solidifies.
Pluton: A general term for an igneous intrusion, often referring to large, irregularly shaped bodies formed at depth.
Batholith: A very large mass of intrusive igneous rock formed deep within the crust.