The Solid Earth - Chapter 1: Igneous Rocks

Question 1

Igneous rocks form when ____ cools and crystallizes

Answer 1

Magma

Question 2

Igneous (molten) rock consists primary of the elements found in ____ material

Answer 2

Silicate

Question 3

Because the magma body is ____ dense than the surrounding rocks, it works its way toward the surface

Answer 3

Less

Question 4

When magma occasionally breaks through the surface, it produces a ______ _______

Answer 4

Volcanic eruption

Question 5

Spectacular explosions that sometimes accompany an eruption are produced by the gases or _____ that escape as the confining pressure lessens near the surface

Answer 5

Volatiles

Question 6

This is similar to magma, except that most of the gaseous component has escaped

Answer 6

Lava

Question 7

What are the two types of rocks that result from magma or lava?

Answer 7

Extrusive or volcanic

Intrusive or plutonic

Question 8

These types of igneous rocks form when lava solidifies

Answer 8

Extrusive

Question 9

These types of rock form when magma crystallizes at depth

Answer 9

Intrusive

Question 10

Magma may contain suspended _____ and a gaseous component

Answer 10

Crystals

Question 11

The liquid portion of a magma body is composed of (ions/atoms) that move freely

Answer 11

Ions

Question 12

What happens to the ions as magma cools and they being to crystallize?

Answer 12

The ions arrange themselves into patterns

Question 13

What is a primary influence on the size of crystals?

Answer 13

The cooling rate

Question 14

When magma cools slowly, relatively ___ centers of crystal growth develops

Answer 14

Few

Question 15

Slow cooling allows ions to ____ over distance

Answer 15

Migrate

Question 16

Slow cooling results in the formation of rather ____ crystals. (large/small)

Answer 16

Large

Question 17

When cooling occurs rapidly, the ions lose their motion and readily ___

Answer 17

combine

Question 18

Quick cooling results in a large number of tiny crystals that all compete for the available _____

Answer 18

ions

Question 19

The outcome of rapid cooling is the formation of a solid mass composed of _____ intergrown crystalls

Answer 19

small

Question 20

Rocks that consist of unordered atoms are referred to as ___

Answer 20

glass

Question 21

This is used to describe the overall appearance of the rock based on the size and arrangement of its interlocking crystals

Answer 21

Texture

Question 22

The rate of cooling is (quick/slow) in magma chambers deep within the crust

Answer 22

Slow

Question 23

The rate of cooling is (quick/slow) for a thin layer of lava upon the earth’s surface

Answer 23

Quick

Question 24

Igneous rocks that form at the earth’s surface or as small masses within the upper crust have a very _________ texture

Answer 24

fine grained

Question 25

The spherical or elongated openings left my gas bubbles trapped as magma solidifies

Answer 25

vesicles

Question 26

In the ____ (upper/lower) zone of a lava flow, cooling occurs rapidly enough to "freeze" the lava and preserve the openings produced by expanding gas bubbles

Answer 26

Upper

Question 27

A name for rocks that form in the upper zone of a lava flow and have preserved openings

Answer 27

Scoria

Question 28

When large masses of magma solidify far below the surface, they form igneous rocks that exhibit a _______ texture

Answer 28

coarse-grained

Question 29

Do all minerals within a magma crystallize at the same rate?

Answer 29

No

Question 30

A rock that has large crystals embedded in a matrix of smaller crystals, probably from a partially cooled eruption has a ______ texture

Answer 30

Porphyritic

Question 31

Rapid cooling may generate rock with a ____ texture when the ions do not have sufficient time to unite

Answer 31

glassy

Question 32

An example of a volcanic rock that often exhibits a glassy texture (often found in obsidian)

Answer 32

Pumice

Question 33

Because of the large percentage of voids, many samples of pumice will (float/sink) when placed in water

Answer 33

Float

Question 34

The mineral makeup of igneous rock is determined by the _____ composition of the magma from which it crystallized

Answer 34

Chemical

Question 35

True or false: a singular magma might produce rocks of varying mineral content

Answer 35

True

Question 36

An arrangement of minerals that take place in order based on cooling rates from one magma

Answer 36

Bowen's reaction series

Question 37

Olivine forms at a (higher/lower temperature)

Answer 37

Higher

Question 38

What four types of igneous rock would form in order from highest temperature (first to crystallize) to lowest temperature (last to crystallize)?

Answer 38

Ultramafic Basaltic Andesitic Granitic

Question 39

Name a mineral formed in ultramafic rock

Answer 39

Olivine

Question 40

What are two names for basaltic rock?

Answer 40

Basalt | Gabbro

Question 41

What type of rock will biotite mica form? (Basaltic or Andesitic)?

Answer 41

Andesitic

Question 42

Name two types of granitic rock

Answer 42

Rhyolite | Granite

Question 43

Name three common minerals for granitic rock in the last stage of cooling

Answer 43

Potassium feldspar Muscovite Mica Quartz

Question 44

The remaining (last) melt of crystallization will have a high ____ content, which eventually crystallizes as quartz

Answer 44

Silica

Question 45

True or false: at one or more stages of the crystallization process, a separation of the solid and liquid components of a magma can occur

Answer 45

True

Question 46

If the earlier formed materials are denser (heavier) than the liquid portion and settle to the bottom of the magma chamber (happens often with dark silicates like olivine and pyroxene)

Answer 46

Crystal setting

Question 47

The process of developing more than one rock type from a common magma

Answer 47

Magmatic differentiation

Question 48

The first minerals to crystallize form rocks that are higher in iron (Fe) and Magnesium (Mg) and are lower in _____.

Answer 48

Silica

Question 49

The iron content of ultramafic rocks and mafic rocks makes them appear ____

Answer 49

Darker

Question 50

The term _____ is derived from Mg and Fe

Answer 50

Mafic

Question 51

Another term used to describe mafic rocks, named after one of the common resulting rocks

Answer 51

Basaltic

Question 52

_____ is the most common extrusive igneous rock

Answer 52

Basalt

Question 53

The upper layers of the oceanic crust consist primary of ____

Answer 53

basalt

Question 54

The first minerals to crystallize produce rocks that are mainly consisting of ____

Answer 54

feldspar and silica

Question 55

The term ____ is applied to granitic rocks

Answer 55

Felsic

Question 56

_____ is the best known igneous rock

Answer 56

Granite

Question 57

Because ____ is tough to erode, it is often the core of eroded mountains

Answer 57

Granite

Question 58

The fine-grained volcanic equivalent of granite

Answer 58

Rhyolite