EXAM 2

Question 1

Where are most of the world’s volcanoes located?

Answer 1

near plate tectonic boundaries

Question 2

What is flux melting?

Answer 2

wet rocks are incorporated into the mantle at subduction zones

Question 3

Which type of magma is least vicious?

Answer 3

basaltic

Question 4

What do Plinian style eruptions consist of?

Answer 4

sustained ejections of ash and gas

Question 5

Which type of lava has a jagged, blocky surface?

Answer 5

A’a Lava

Question 6

What are minerals?

Answer 6

naturally occurring, inorganic, crystalline solid having a definite chemical composition

Question 7

What is a crystalline structure?

Answer 7

atoms arranged in a specific geometrical pattern

Question 8

What are the types of volcanic forms?

Answer 8

basaltic, andesitic, and rhyolitic

Question 9

What are the volcanic shapes and sizes?

Answer 9

shield, stratovolcano (sm, m, and l), large cinder cone

Question 10

Example of a shield volcano?

Answer 10

Hawaii

Question 11

Example of a stratovolcano (large)?

Answer 11

Shasta

Question 12

Examples of a stratovolcano (medium)?

Answer 12

Fuji

Question 13

Examples of a stratovolcano (small)?

Answer 13

Vesuvius

Question 14

Example of a large cinder cone?

Answer 14

Sunset crater

Question 15

What does a Hawaiian style eruption look like?

Answer 15

fluid, ‘glowing-red’ lava; lava lakes form in crater

Question 16

What does Strombolian style eruption look like?

Answer 16

fire fountaining, forms cinder cones

Question 17

What does Vulcanian style eruptions look like?

Answer 17

‘cannon’ explosions with ballistic trajectories of ash and rock fragments, ash plume usually very dark gray to black

Question 18

What does Pelean style eruptions look like?

Answer 18

pyroclastic flow generated from the collapse of a ‘spine’

Question 19

What type of lava is in a stratovolcano?

Answer 19

outside -andesitic

inside -rhyolitic

Question 20

What can a stratovolcano produce?

Answer 20

vulcanian, plinian, and pelean (pyroclastic flow)

Question 21

What are the causes of a stratovolcano?

Answer 21

• sector collapse of a plinian column

- collapse of spine/dome

Question 22

How do you identify minerals?

Answer 22

• color
• streak
• luster-hardness
• cleavage

Question 23

What is Moh’s hardness scale?

Answer 23

1) talc
2) gypsum
3) calcite
4) fluorite
5) apatite
6) orthoclase
7) quartz
8) topaz
9) corundum
10) diamond

Question 24

How to identify minerals by color?

Answer 24

some are one color, some are many colors

Question 25

How to identify minerals by streak?

Answer 25

color of mineral in powdered form

Question 26

How to identify minerals by luster?

Answer 26

the way a mineral reflects light

Question 27

What are the two types of luster?

Answer 27

metallic and nonmetallic

Question 28

How to identify minerals by hardness?

Answer 28

Moh's hardness scale

Question 29

How to identify minerals by cleavage?

Answer 29

tendency to break along planes of weakness

Question 30

What is a fracture?

Answer 30

minerals without cleavages

Question 31

What is a conchoidal fracture?

Answer 31

mineral that caves in, ribs along the surface

Question 32

What mineral has two directions of cleavage at about 90 degrees with a striking pink salmon pink color?

Answer 32

Potassium feldspar

Question 33

Minerals with one cleavage will break into what?

Answer 33

flat sheet-like pieces

Question 34

Where can magma form?

Answer 34

intrusive or extrusive

Question 35

What is intrusive magma formation?

Answer 35

magma cooling under the surface; lose heat slowly

Question 36

What is extrusive magma formation?

Answer 36

magma that exits the earth; cools rapidly

Question 37

How is rock formed?

Answer 37

by crystallization of molten magma

Question 38

Why does magma rise?

Answer 38

hot rock is less dense and moves to the top

Question 39

What are the characteristics of intrusive magma?

Answer 39

cools at depth; invades colder country rock; inflation of fractures pushes rock aside

Question 40

What is stoping?

Answer 40

when rocks fall into magma as it rises; blocks country rock, falls off and are incorporated into magma

Question 41

What is a batholith?

Answer 41

enormous magma chamber

Question 42

How are dikes created?

Answer 42

magma that goes into fractures

Question 43

What are the three types of dikes?

Answer 43

ring, radial, and sheet

Question 44

What is a dike?

Answer 44

tabular intrusion that cuts discordantly

Question 45

What is discordant?

Answer 45

cut across layers

Question 46

What is a laccolith?

Answer 46

large mushroom shaped pond (more viscious)

Question 47

What is a lopolith?

Answer 47

large scoop shaped pond (less viscious)

Question 48

What is a sill?

Answer 48

tabular intrusive body that intrudes parallel to layering of preexisting rock; concordant

Question 49

What is concordant?

Answer 49

magma that squeezes between layers

Question 50

What is a pluton?

Answer 50

large, deep igneous body that results from emplacement and crystallization of magma beneath the surface

Question 51

How can igneous rocks be classified?

Answer 51

- texture | - composition

Question 52

What is texture (igneous rocks)?

Answer 52

crystal size and nature of interlocking crystals

Question 53

What is composition (igneous rocks)?

Answer 53

types of minerals in the rocks

Question 54

Intrusive rocks have what texture?

Answer 54

phaneritic

Question 55

What is phaneritic?

Answer 55

crystals large enough to see with eye

Question 56

Extrusive rocks have what texture?

Answer 56

aphanitic

Question 57

What is aphanitic?

Answer 57

crystals too small to be seen with naked eye

Question 58

What is quenched magma?

Answer 58

magma that cools instantly with glass-like appearance

Question 59

What is porphyritic texture?

Answer 59

igneous rock with two distinct crystal sizes

Question 60

What is pegmatitic texture?

Answer 60

extremely large crystals

Question 61

What are the textures of igneous rocks?

Answer 61

- glassy - vesicular - scoria - pyroclastic

Question 62

What are the components of intrusive igneous rock composition?

Answer 62

(felsic) Granite (inter. ) Diorite (mafic) Gabbro

Question 63

What are the three areas igneous rock can fall in?

Answer 63

- felsic - intermediate - mafic

Question 64

What are the components of extrusive igneous rock composition?

Answer 64

(felsic) rhyolite (inter. ) andesite (mafic) basalt