Igneous Rocks Review

Igneous Rocks Review

Chapter 5 Test Practice

Multiple Choice

Igneous rocks that cool slowly inside of Earth's crust are...

• intrusive

• extrusive

Multiple Choice

Which of these hot, melted substances can be found deep underground?

• magma

• lava

Multiple Choice

Which minerals crystallize first in cooling magma, according to Bowen's reaction series?

• olivine and Ca-feldspar

• quartz and K-feldspar

Multiple Choice

What relationship is illustrated by Bowen's reaction series?

• temperature vs mineral formation

• temperature vs viscosity

• mineral type vs water content

• partial melting vs pressure

Multiple Choice

The longer it takes for magma to cool...

• the larger the mineral crystals may grow

• the smaller the mineral crystals will be

Multiple Choice

This igneous rock's large crystals indicate that it is...

• extrusive, and formed deep underground.

• intrusive, and formed near the surface.

• intrusive, and formed deep underground.

• extrusive, and formed near the surface.

Multiple Choice

Which of these indicates that an igneous rock's crystals are all large enough to be seen with the unaided eye?

• coarse/phaneritic

• fine/aphanitic

• acrystalline/ glassy

• pyroclastic

• vesicular (frothy)

Multiple Choice

Which of these indicates that an igneous rock cooled off so quickly that crystals could not form?

• coarse/phaneritic

• fine/aphanitic

• acrystalline/ glassy

• pyroclastic

• vesicular (frothy)

Multiple Choice

Which of these indicates that an igneous rock cooled off so quickly that gas bubbles were trapped in the rock?

• coarse/phaneritic

• fine/aphanitic

• acrystalline/ glassy

• pyroclastic

• vesicular (frothy)

Multiple Choice

Which of these indicates that an igneous rock's crystals are too small to be seen without a microscope?

• coarse/phaneritic

• fine/aphanitic

• acrystalline/ glassy

• pyroclastic

• vesicular (frothy)

Multiple Choice

Which of these indicates that an igneous rock was made from broken solids that fused together after they were erupted?

• coarse/phaneritic

• fine/aphanitic

• acrystalline/ glassy

• pyroclastic

• vesicular (frothy)

Multiple Choice

Igneous rock that forms from lava on Earth's surface

• Organic Rock

• Intrusive Rock

• Clastic Rock

• Extrusive Rock

Multiple Choice

A type of rock that forms from the cooling of molten rock at or below the surface of the earth

• Igneous Rock

• Metamorphic Rock

• Sedimentary Rock

• chemical Rock

Multiple Choice

What kind of texture does igneous rock have when magma cools rapidly?

• coarse-grained

• medium-grained

• large-grained

• fine-grained

Multiple Choice

Why are igneous rocks so strong?

• Because of their water content.

• Because of their colors.

• Because of their interlocking mineral grains.

Multiple Choice

Which type of igneous rock tends to be light-colored due to its very high silica content?

• felsic

• intermediate

• mafic

• ultramafic

Multiple Choice

Valuable ore deposits and rare metals are often associated with...

• thin crustal areas

• oceans

• oil deposits

• layered igneous intrusions

Multiple Choice

Which of these best describes a layered intrusion?

• bands of minerals that mirror Bowen's reaction series

• a series of volcanic flows, one on top of the other

• veins composed primarily of quartz

• alternating bands of sandstone and siltstone

Multiple Choice

Igneous rocks form when magma...

• undergoes radioactive decay

• weathers to form sediments

• is heated, squeezed, and deformed

• cools and crystallizes

Multiple Choice

What kind of texture does igneous rock have when magma cools SLOWLY?

• coarse-grained

• large-grained

• fine-grained

• medium-grained

Multiple Choice

A slowly cooling body of magma will grow visible crystals. If something causes that magam to rapidly cool (like an eruption), the rest of the melted material will form lots of tiny crystals at once. What is the term for this 2-different-sizes crystal texture?

• phaneritic

• porphyritic

• pegmatitic

• bicrystalline

Multiple Choice

Which type of igneous rock is made from magma with >66% silica, resulting in the formation of light (or pink) minerals such as quartz, muscovite mica, and both K- and Na- feldspars?

• felsic

• intermediate

• mafic

• ultramafic

Multiple Choice

Which type of igneous rock is made from magma with 52 to 66% silica, resulting in the formation of an even mix of light and dark minerals such as pyroxene and both Ca- and Na-feldspars?

• felsic

• intermediate

• mafic

• ultramafic

Multiple Choice

Which type of igneous rock is made from iron and magnesium-rich magma with 45 to 52% silica, resulting in the formation of mostly dark minerals such as pyroxene, amphibole, and Ca-feldspar?

• felsic

• intermediate

• mafic

• ultramafic

Multiple Choice

Which type of igneous rock is made from magma with <45% silica, very high iron and magnesium levels, and forms with mostly green(ish) minerals such as pyroxene and olivine?

• felsic

• intermediate

• mafic

• ultramafic

Multiple Choice

A mining company just found a large area of pegmatite! What is a pegmatite?

• A mafic igneous rock with visible crystals.

• Any igneous rock with extremely small crystals.

• Any igneous rock with penny-sized crystals, or larger.

• An intermediate igneous rock with grains of two different sizes.