Chapter 4 Test - Igneous Processes and Volcanoes

What is the primary factor that determines the texture of igneous rocks?

• The color of the minerals

• The cooling history of the magma

• The presence of fossils

• The age of the rock

Which type of igneous rock is formed when magma cools slowly beneath the Earth's surface?

• Intrusive igneous rock

• Volcanic glass

• Sedimentary rock

• Extrusive igneous rock

Match the following components with their corresponding rock types.

• Mafic igneous rocks

• High silica content

• Aluminum-rich metamorphic rocks

• High aluminum content

• Potassium-rich sedimentary rocks

• High iron and magnesium content

• Felsic igneous rocks

• High potassium content

What is the term for the large crystals found in a porphyritic texture?

• Groundmass

• Phenocrysts

• Vesicles

• Matrix

Which volcanic rock is known for its ability to float on water due to its vesicular texture?

• Pumice

• Obsidian

• Granite

• Basalt

What is the primary cause of decompression melting at mid-ocean ridges?

• Increase in temperature

• Addition of volatiles

• Decrease in pressure

• Increase in pressure

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-3

Which type of volcano is characterized by broad, low-angle flanks and is typically associated with hotspots?

• Stratovolcano

• Cinder cone

• Shield volcano

• Caldera

The main difference between mafic and felsic igneous rocks is that mafic rocks (a)   .

• Mafic rocks have higher silica content

• Felsic rocks have higher iron content

• Mafic rocks crystallize at higher temperatures

• Felsic rocks are darker in color

Which process involves the addition of volatiles to mantle material, causing it to melt?

• Partial melting

• Heat-induced melting

• Decompression melting

• Flux melting

Match the following volcanic hazards with their descriptions.

• Harmful gases released during eruptions

• Earthquakes

• Molten rock flowing from a volcano

• Toxic gases

• Seismic activity causing ground shaking

• High-speed ash and gas clouds

• Rapidly moving clouds of ash and gas

• Lava flows

Tags

NGSS.MS-ESS3-2