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Questions and Answers
Which type of rock is formed from magma that solidifies underneath the Earth's crust?
Which type of rock is formed from magma that solidifies underneath the Earth's crust?
What is a characteristic of extrusive igneous rocks due to the rapid cooling of lava on the Earth's surface?
What is a characteristic of extrusive igneous rocks due to the rapid cooling of lava on the Earth's surface?
Which intrusive igneous body is composed of several smaller plutons and can reach hundreds of kilometers in length?
Which intrusive igneous body is composed of several smaller plutons and can reach hundreds of kilometers in length?
What is the example of a dike mentioned in the text?
What is the example of a dike mentioned in the text?
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What type of magma forms pumice, a light-colored, low density, and vesicle-rich extrusive igneous rock?
What type of magma forms pumice, a light-colored, low density, and vesicle-rich extrusive igneous rock?
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What is the example of a sill mentioned in the text?
What is the example of a sill mentioned in the text?
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What is the term for large igneous bodies that solidify near the Earth's surface and are only exposed when overlying rocks erode?
What is the term for large igneous bodies that solidify near the Earth's surface and are only exposed when overlying rocks erode?
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What may displace intrusive bodies and change their original orientation?
What may displace intrusive bodies and change their original orientation?
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What are igneous rocks formed from?
What are igneous rocks formed from?
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What causes magma to rise to the Earth's surface?
What causes magma to rise to the Earth's surface?
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What are the conditions required for rocks to melt and form magma?
What are the conditions required for rocks to melt and form magma?
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What type of rocks are formed when magma is trapped underneath the surface and slowly cools?
What type of rocks are formed when magma is trapped underneath the surface and slowly cools?
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Where are melts commonly found?
Where are melts commonly found?
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What is the source of heat that partially melts small amounts of rocks in the upper mantle?
What is the source of heat that partially melts small amounts of rocks in the upper mantle?
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What is the characteristic of extrusive igneous rocks due to the rapid cooling of lava on the Earth's surface?
What is the characteristic of extrusive igneous rocks due to the rapid cooling of lava on the Earth's surface?
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What are the three main types of rocks observed on the Earth's surface?
What are the three main types of rocks observed on the Earth's surface?
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How are igneous rocks formed?
How are igneous rocks formed?
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What makes magma rise to the Earth's surface?
What makes magma rise to the Earth's surface?
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Where are the rising melts commonly found?
Where are the rising melts commonly found?
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What conditions are required for rocks to melt?
What conditions are required for rocks to melt?
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What type of rocks are formed when magma is trapped underneath the surface and slowly cools?
What type of rocks are formed when magma is trapped underneath the surface and slowly cools?
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What is the source of heat that partially melts small amounts of rocks located in the upper mantle?
What is the source of heat that partially melts small amounts of rocks located in the upper mantle?
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Study Notes
Intrusive vs Extrusive Igneous Rocks
- Volcanic rocks are formed when molten material, called lava, is extruded onto the Earth's surface through volcanic vents and fissures.
- The rapid cooling of lava on the surface results in fine-grained or glassy-textured rocks with trapped gases known as vesicles.
- Pumice is an example of extrusive igneous rock, characterized by its light-colored, low density, and vesicle-rich appearance, formed from felsic magma.
- Plutonic rocks, or intrusive rocks, form from magma that does not reach the Earth's surface and solidifies slowly underneath the crust.
- Granite is an example of intrusive igneous rock, formed by slow cooling of viscous felsic magma, resulting in coarse-grained, light-colored crystalline texture.
- Plutons are large igneous bodies that solidify near the Earth's surface and are only exposed when overlying rocks erode, forming batholiths, dikes, and sills.
- Batholiths are irregularly shaped plutons composed of several smaller plutons, such as granite, quartz monzonite, or diorite, and can reach hundreds of kilometers in length.
- Dikes and sills are formed when magma intrudes pre-existing rock bodies and crystallizes as sheet intrusions, with dikes cutting across rock layers and sills occurring parallel to bedding planes.
- An example of a dike is the Mackenzie dike swarm in the Northwest Territories, Canada, while a sill example is the Dolerite sills in Karroo, South Africa.
- Plutons can also form batholiths, such as the Sierra Nevada Batholith in California and Pikes Peak granite in Colorado.
- Deformations in the rock, like folding and faulting, may displace intrusive bodies and change their original orientation.
- Understanding the differences between intrusive and extrusive rocks is essential in geology and has practical applications in fields like construction and resource exploration.
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Description
Test your knowledge of intrusive and extrusive igneous rocks with this quiz! Explore the formation, characteristics, and examples of volcanic and plutonic rocks, including their impact on geology and practical applications in various fields.
