Question 1

The two main categories of igneous rocks are ____________________ and ____________________.

Accepted Answer

volcanic, plutonicplutonic, volcanicextrusive, intrusiveintrusive, extrusive

Question 2

A(n)____ pluton has boundaries that parallel the layering in the country rock.

Accepted Answer

A) concordant 
B) discordant 
C) correspondent 
D) analogous 
E) disruptive 
A) concordant 
B) discordant 
C) correspondent 
D) analogous 
E) disruptive A

Question 3

Pyroclastic igneous rock forms from ____.

Accepted Answer

A) explosive volcanic activity 
B) rapidly cooling plutons 
C) viscous lava flows 
D) basalt and gabbro 
E) melting of country rock 
A) explosive volcanic activity 
B) rapidly cooling plutons 
C) viscous lava flows 
D) basalt and gabbro 
E) melting of country rock A

Question 4

Stoping is the process in which ____.

Accepted Answer

A) pyroclastic flows are tranformed into obsidian 
B) rising magma detaches and engulfs pieces of country rock 
C) the viscosity of magma changes due to changes in silica content 
D) dikes are formed due to intense heat in the country rock 
E) erosion exposes batholiths 
A) pyroclastic flows are tranformed into obsidian 
B) rising magma detaches and engulfs pieces of country rock 
C) the viscosity of magma changes due to changes in silica content 
D) dikes are formed due to intense heat in the country rock 
E) erosion exposes batholiths

Question 5

Distinguish between rhyolite tuff and welded tuff.

Accepted Answer

Most tuff is silica rich, ligh

Question 6

Partial melting of oceanic crust and silica-rich sediments of continental margins ____.

Accepted Answer

A) yields magma richer in basalt than the source rock 
B) is a major cause of earthquakes 
C) causes off-gassing which increases global warming 
D) yields magma richer in silica than the source rock 
E) will form sedimentary rock 
A) yields magma richer in basalt than the source rock 
B) is a major cause of earthquakes 
C) causes off-gassing which increases global warming 
D) yields magma richer in silica than the source rock 
E) will form sedimentary rock

Question 7

An igneous rock with no visible crystals ____.

Accepted Answer

A) has a phaneritic texture 
B) cooled quickly in a magma chamber 
C) slowly on Earth's surface 
D) cooled quickly on Earth's surface 
E) is granite 
A) has a phaneritic texture 
B) cooled quickly in a magma chamber 
C) slowly on Earth's surface 
D) cooled quickly on Earth's surface 
E) is granite

Question 8

Most igneous rocks are classified as either volcanic or plutonic based on their ____.

Accepted Answer

A) size and location 
B) magnesium content 
C) iron content 
D) texture and composition 
E) size and composition 
A) size and location 
B) magnesium content 
C) iron content 
D) texture and composition 
E) size and composition

Question 9

Although all compositions are represented, most plutons are ____ rocks.

Accepted Answer

A) felsic 
B) intermediate 
C) mafic 
D) pyroclastic 
E) basaltic 
A) felsic 
B) intermediate 
C) mafic 
D) pyroclastic 
E) basaltic

Question 10

Batholiths are large plutonic bodies produced by a single, voluminous intrusion of magma in a region.

Accepted Answer

A) True 
 B)False

Question 11

One example of a vesicular felsic rock is ____.

Accepted Answer

A) pumice 
B) basalt 
C) obsidian 
D) granite 
E) mica 
A) pumice 
B) basalt 
C) obsidian 
D) granite 
E) mica

Question 12

Most batholiths ____.

Accepted Answer

A) assimilate all country rock as they move upward 
B) form during a volcanic eruption 
C) are composed of obsidian and pumice 
D) have a pyroclastic texture and are usually small geological features 
E) were emplaced by forceful injection and stoping as magma moved upward 
A) assimilate all country rock as they move upward 
B) form during a volcanic eruption 
C) are composed of obsidian and pumice 
D) have a pyroclastic texture and are usually small geological features 
E) were emplaced by forceful injection and stoping as magma moved upward

Question 13

Why are rhyolite flows less common than basalt flows?

Accepted Answer

Rhyolitic magmas are more visc

Question 14

The most widely accepted explanation for chains of volcanoes in the oceans and lines of volcanoes on land is that they formed at ____.

Accepted Answer

A) divergent plate boundaries 
B) normal faults 
C) hot spots 
D) convergent plate boundaries 
E) transform faults 
A) divergent plate boundaries 
B) normal faults 
C) hot spots 
D) convergent plate boundaries 
E) transform faults

Question 15

Some plutons are emplaced by forceful injection as magma moves upward through country rock.

Accepted Answer

A) True 
 B)False

Question 16

Rapid cooling of magma results in a fine-grained ____________________ texture. Slow cooling of magma results in a course-grained ____________________ texture.

Accepted Answer

aphanitic,

Question 17

____________________ are concordant, mushroom-shaped plutons.

Accepted Answer

The answer of ____________________ are concordant, mushroom-shaped plutons....

Question 18

Melting of Earth's crust yields mostly silica-rich magmas because ____.

Accepted Answer

A) the most abundant minerals in Earth's crust are silicates 
B) silica is more easily melted than other minerals 
C) many minerals produce silica when melted 
D) silica has extremely low viscosity and move quickly up to Earth's crust from far underground 
E) when silicon reacts with sodium chloride it form silica 
A) the most abundant minerals in Earth's crust are silicates 
B) silica is more easily melted than other minerals 
C) many minerals produce silica when melted 
D) silica has extremely low viscosity and move quickly up to Earth's crust from far underground 
E) when silicon reacts with sodium chloride it form silica

Question 19

Basalt and gabbro are compositional equivalents, which means that they ____.

Accepted Answer

A) are both formed from the same pluton 
B) have the same texture but are made up of different minerals 
C) are made up of the same minerals and are the result of explosive igneous activity 
D) are made up of the same minerals but have different textures 
E) have the same texture but one is mafic and the other is felsic 
A) are both formed from the same pluton 
B) have the same texture but are made up of different minerals 
C) are made up of the same minerals and are the result of explosive igneous activity 
D) are made up of the same minerals but have different textures 
E) have the same texture but one is mafic and the other is felsic

Question 20

The process of assimilation ____.

Accepted Answer

A) includes melting and incorporation of inclusions of country rock 
B) includes the inclusion of country rock in an extrusive magma 
C) occurs in all plutons 
D) results in additional heating of a magma body 
E) separates mafic rock from felsic rock 
A) includes melting and incorporation of inclusions of country rock 
B) includes the inclusion of country rock in an extrusive magma 
C) occurs in all plutons 
D) results in additional heating of a magma body 
E) separates mafic rock from felsic rock

Exam 4: Igneous Rocks and Plutons

The two main categories of igneous rocks are ____________________ and ____________________.

A(n)____ pluton has boundaries that parallel the layering in the country rock.

Pyroclastic igneous rock forms from ____.

Stoping is the process in which ____.

Distinguish between rhyolite tuff and welded tuff.

Partial melting of oceanic crust and silica-rich sediments of continental margins ____.

An igneous rock with no visible crystals ____.

Most igneous rocks are classified as either volcanic or plutonic based on their ____.

Although all compositions are represented, most plutons are ____ rocks.

Batholiths are large plutonic bodies produced by a single, voluminous intrusion of magma in a region.

One example of a vesicular felsic rock is ____.

Most batholiths ____.

Why are rhyolite flows less common than basalt flows?

The most widely accepted explanation for chains of volcanoes in the oceans and lines of volcanoes on land is that they formed at ____.

Some plutons are emplaced by forceful injection as magma moves upward through country rock.

Rapid cooling of magma results in a fine-grained ____________________ texture. Slow cooling of magma results in a course-grained ____________________ texture.

____________________ are concordant, mushroom-shaped plutons.

Melting of Earth's crust yields mostly silica-rich magmas because ____.

Basalt and gabbro are compositional equivalents, which means that they ____.

The process of assimilation ____.

Understanding Earth: a Dynamic and Evolving Planet

Plate Tectonics: a Unifying Theory

Minerals: The Building Blocks of Rocks

Volcanoes and Volcanism

Weathering, Erosion, and Soil

Sediment and Sedimentary Rocks

Metamorphism and Metamorphic Rocks

Earthquakes and Earthapos;s Interior

Deformation, Mountain Building, and Earthapos;s Crust

Mass Wasting

Running Water--Streams and Rivers

Groundwater

Glaciers and Glaciation

The Work of Wind and Deserts

Oceans, Shorelines, and Shoreline Processes

Geologic Time: Concepts and Principles

Organic Evolution--The Theory and Its Supporting Evidence

Precambrian Earth and Life History

Paleozoic Earth History

Paleozoic Life History

Mesozoic Earth and Life History

Cenozoic Earth and Life History

Filters

The two main categories of igneous rocks are and .

Rapid cooling of magma results in a fine-grained texture. Slow cooling of magma results in a course-grained texture.