Geol 1002 Test 1

Front 1

The Earth is a

Back 1

unique, evolving system.

Front 2

Geology helps you understand

Back 2

physical science

Front 3

____ _____ explains many Earth processes

Back 3

Plate tectonics

Front 4

The Earth is a

Back 4

very old planet

Front 5

_________ and _________ processes drive geologic phenomena

Back 5

Internal; external

Front 6

__________ _________ affect our environment.

Back 6

Geologic phenomena

Front 7

Physical aspects of the Earth system are linked to

Back 7

life processes

Front 8

Science comes from ______________ and people make ________ _____________

Back 8

observation; scientific discoveries.

Front 9

The earth is one of _____ planets (____ ____________ and ____ ____ or ___ ______) orbiting our sun, which is one of _____ ________ ________ stars of the revolving, spiral shaped ______ ____ galaxy. Hundreds of billions of _______ speckle the visible universe.

Back 9

eight; four terrestrial, four gas, ice giants, three hundred billion, Milky Way, galaxies

Front 10

According to the ___ ____ ______, a cataclysmic explosion at _____ ___ formed the universe, which has been _________ ever since. _____ formed during the Big Bang collected into nebulae, which due to _________, collapsed into ______ _____, the first stars.

Back 10

Big Bang Theory; 13.7 GA; expanding; Atoms; gravity; dense balls.

Front 11

___________ ____________ formed in stars and supernovas added to gases in ___________ from which new generations of stars formed. Planets formed from ______ of ____ and ___ ________ the stars. As they formed, planets differentiated, with ______ _________ sinking to the center.

Back 11

Heavier elements; nebulae; rings; dust; ice orbiting; denser materials

Front 12

The Earth produces a ________ _____ that deflects solar wind. An atmosphere of __ and __ gas surrounds the planet. Oceans cover __% of the surface, and the land the remainder. The difference between the highest and lowest points is only about ___% of the radius.

Back 12

magnetic field; N2; O2; 70; 0.3

Front 13

The Earth consists of many materials, the most common of which is ________ rock. Studies, including analysis of earthquake waves show that the Earth can be divided into three layers---the _____, the ______, and the ____. Temperature and pressure increase with _____.

Back 13

silicate; crust; mantle; core; depth

Front 14

Earth's outermost layer, the _____, is very ____. Oceanic and continental crust differ in ___________. Most of Earth's mass lies in the ______. A ________ core lies at this planet's center. The crust and outermost mantle together comprise the _____ ___________.

Back 14

crust; thin; composition; mantle; metallic; rigid lithosphere

Front 15

_______ argued that the continents were once merged into a supercontinent called Pangaea that later broke up to produce smaller continents that _______ apart. The ________ ______ of __________, as well as the ____________ of _______ _______ _____, _______, and ____ _____ all make better sense if Pangaea existed.

Back 15

Wegener; drifted; matching shapes; coastlines; distribution; ancient climate belts; fossils; rock units

Front 16

Study of ______________ indicates that the continents have moved relative to the Earth's ________ _____. Each continent has a different apparent _____ ______ ____, which is only possible if the continents move ("drift") relative to each other.

Back 16

paleomagnetism; magnetic poles; polar wander path

Front 17

New studies of the seafloor led to the proposal of ________ _________. New seafloor forms at ___-_____ ______ and then moves away from the axis, so ocean basins can get wider with time. Old ocean floor _____ back into the mantle by __________. As ocean basins grow or shrink, __________ _____.

Back 17

seafloor spreading; mid-ocean ridges; sinks; subduction; continents drift

Front 18

______ ________ _________ form because reversals of the Earth's magnetic polarity take place while ________ _________ occurs. The discovery of these _________, as well as documentation that the seafloor gets _____ away from the ridge axis, proved that the seafloor spreading hypothesis is _______.

Back 18

Marine magnetic anomalies; seafloor spreading; anomalies; older; correct

Front 19

Earth's lithosphere is divided into about ______ places that move relative to each other. Geologists recognize three different types of plate boundaries (_________, __________, and _________) based on relative motion across the boundary. Plate boundaries are determined by _______ _____.

Back 19

twenty; divergent; convergent; transform

Front 20

Seafloor spreading occurs at _________ _____ boundaries, defined by mid-ocean ridges. New oceanic crust solidifies from ________ _____ along the ridge axis. As plates move away from the axis, they ____, and the ____________ mantle forms and thickens.

Back 20

divergent plate; basaltic magma; cool; lithospheric

Front 21

At a __________ _____ boundary, an oceanic plate _____ into the mantle beneath the edge of another plate. A ________ ___ and a ______ delineate such plate boundaries, and ___________ happen along the contract between the ___ places as well as in the downgoing slab.

Back 21

convergent plate; sinks; volcanic arc; trench; two

Front 22

At _________ _____ boundaries, one plate slips ________ past another. Most transform boundaries link of segments of ___-_____ ______, but some, such as the ___ _______ _____, cut across continental crust.

Back 22

transform plate; sideways; mid-ocean ridges; San Andreas Fault

Front 23

A ______ _________ marks the point where three plate boundaries join. A hot spot is a place where _________ may be due to _______ at the top of a mantle plume. As a plate moves over a plume, a ___-____ _____ develops.

Back 23

triple junction; volcanism; melting; hot-spot track

Front 24

Rifting can split a continent __ ____ and can lead to the formation of a new _________ _____ boundary. When two buoyant _______ ______, such as continents and island arcs, collide, a ________ ____ forms and __________ eventually ceases.

Back 24

in two; divergent plate; crustal blocks; mountain belt; subduction

Front 25

Plates move at _ to __ cm/yr. Relative motion specifies the rate that a plate moves ________ to its ________, whereas absolute motion specifies the rate that a plate moves ________ to a _____ _____ beneath the plate. ___ ____________ can detect relative plate motions directly.

Back 25

1; 15; relative; neighbor; relative; fixed point; GPS measurement

Front 26

Minerals are ______ with a ___________ structure (an _______ ___________ of _____ inside) and a _________ ________ _______. They form by _______ _________ in the Earth system.

Back 26

solids; crystalline; orderly arrangement; atoms; definable chemical formula; natural processes

Front 27

The crystal structure of minerals is defined by a _______ _________ ___________ of _____ that has ________. Minerals can form by ______________ of a ____, by _____________ from a _____ ________ or a ___, or by _____________ of _____ in a _____.

Back 27

regular geometric arrangement; atoms; symmetry; solidification; melt; precipitation; water solution; gas; rearrangement; atoms; solid

Front 28

The characteristics of minerals (such as _____, ______, ______, _______ ______, ________, ________ _______, ________, _________, and ________ with ____) are a manifestation of the _______ _________ and ________ ___________ of minerals.

Back 28

color; streak; luster; crystal shapes; hardness; specific gravity; cleavage; magnetism; reaction; acid; crystal structure; chemical composition

Front 29

The _____ known minerals can be organized into a relatively small number of classes based on ________ ______. Most minerals are _________, which contain _______-______ __________ arranged in various ways.

Back 29

4000; chemical makeup; silicates; silicon-oxygen tetrahedra.

Front 30

Gemstones are particularly ____ and ________ minerals. The gems or jewels found in jewelry have been _______ using a lap-- the _____ are not _______ _______ _____ or ________ ________. The fire of a jewel comes from the way it ________ _____ internally.

Back 30

rare; beautiful; faceted; facets; natural crystal facets; cleavage surfaces; reflects light

Front 31

Molten rock underground is called _____, whereas molten rock that has come out of a vent at the Earth's surface is ____. Solidification of magma produces _________ rocks. Solidification of lava, either __ _____ or on the _______, or as _________ ______ __ ___ ___, produces _________ _______ rocks.

Back 31

magma; lava; intrusive; in flows; surface; fragments cooled in the air; extrusive igneous

Front 32

The Earth is ___ inside. Even so, the crust and mantle are _____, except in special places where pre-existing solid rock undergoes _______. _______ can be triggered by a ________ in ________, ________ of _________ and/or _________ of ___ _____ from ______ _____. Geologists classify magma based on its ___________.

Back 32

hot; solid; melting; melting; decrease; pressure; addition; volatiles; injection; hot magma; deeper below; composition

Front 33

Magma rises because it's _______ and because of ________ due to overlying rocks. The rate of melt movement is affected by _________, which depends on ___________ and ___________. When molten rocks enters a ______ environment, it _______. The rate of cooling depends on the ___________ and _____ of the magma body.

Back 33

buoyant; pressure; viscosity; composition; temperature; cooler; freezes; environment; shape

Front 34

Molten rock can extrude either as a ___ ____ or as ___________ ______. Intrusions underground __________ igneous rock with ____ ____. ________ ________ (sills and dykes) are ___-____ intrusions. Blob-shaped intrustions are ____. Huge ____________ consist of many plutons.

Back 34

lava flow; pyroclastic debris; juxtapose; wall rock; Tabular intrusions; wall-like; plutons; batholiths

Front 35

Igneous rocks come in a variety of ___. Mafic rocks tend to be ________ than felsic rocks. Textures of igneous rocks vary from _____, to ____-_______, to _____-_______. Geologists classify and assign names to igneous rocks based on ________ and _________.

Back 35

colors; darker; glassy; fine-grained, coarse-grained; texture; composition

Front 36

The formation of igneous rocks can be understood in the context of _____-_________ ______. ____ ________ due to release of fluids from subducting slabs produces melts at __________ _______. Melting at ___ _____ is probably due to ____________ of ______ _____________ also triggers melting beneath _____ and ___-_____ ______. _________ of ___ ______-_______ _____ into the crust at _____ and __________ _______ causes melting of the _____.

Back 36

plate-tectonics; theory; Flux melting; convergent margins; hot spots; decompression rising asthenosphere; rifts; mid-ocean ridges; Injection; hot mantle-derived magma; rifts; convergent margins; crust

Front 37

* The universe is _________.

-The other galaxies are all moving _____ from us.

-We're not the ______ of the universe

-Shows that everything originated from one _____

Back 37

expanding; away; center; point

Front 38

*Looking at the absorption spectra of the star

-we know what it ______ look like

-we see we have the _____ _______ but not in the right place.

Back 38

should; right pattern

Front 39

*Where do matter and energy come from?

-________ _________ formed within a few seconds. After three minutes, __ and __, __, _ were all created by ______.

- only works up until atomic number __ (____)

-Gravity collected ______ and made _____.

-__________ released enough energy to make atomic elements with numbers larger than __.

Back 39

Hydrogen atoms; He; Be; Li; B; fusion; 26; Iron; gravity; stars; Supernovas; 26

Front 40

*Sun formed
-_________ ______ (gravitational)
-Energy in the planets meets at the ____

Back 40

potential energy; core

Front 41

Something smashed into the Earth and broke a piece off and that's the ____.

Back 41

Moon

Front 42

Volcanoes spew out _________,

Back 42

volatiles

Front 43

We have to wait until its ____ enough to have liquid water.

Back 43

cool

Front 44

The Earth system includes the __________, _________ (anything _____), ___________ (all _____ on Earth), and ___________ (all of the stuff made out of ____) [___ what we mean when we say lithosphere in Geology]

Back 44

atmosphere, biosphere; alive; hydrosphere; water; lithosphere; rock; not

Front 45

The continents all ___ ________.

Back 45

fit together

Front 46

There is not the same amount of __________ on Earth.

Back 46

elevations

Front 47

We know more about the _______ of ____ than our own seafloor.

Back 47

surface; Mars

Front 48

___ __ up is space.

Back 48

100 km

Front 49

Ocean floors are _-_ km deep

Back 49

4; 5

Front 50

The Earth is ______.

Back 50

differentiated.

Front 51

Back 51

Compositional Layers; Continental; Oceanic; Mantle; Core; Mechanical Layers; lithosphere; aesthenosphere; mesosphere; outer core; inner core

Front 52

The boundary between crust and mantle is called the ____.

Back 52

Moho

Front 53

The difference in the layers is their _______ ___________.

Back 53

chemical composition

Front 54

Mechanical difference in layers is in their _________ (how it flows)

Back 54

viscosity

Front 55

*Iron is the ________ element that we have a lot of.

-Most of the iron is in the _____ ____.

-Most trace elements occur in the _____.

Back 55

heaviest; inner core; crust

Front 56

Seismic waves react ____________ in the crust and the mantle.

Back 56

differently

Front 57

_____ and _____ are too simple.

Back 57

Solid; liquid

Front 58

There are different levels of __________. Water is the _____ viscous. The ______ the viscosity, the ____ is flows.

Back 58

viscosity; least; higher; less

Front 59

The word "__________" is not really used.

Back 59

mesosphere

Front 60

*Plate tectonics

-______ are ___________ that is moving over an ______________ that is able to flow.

-Crust and ____________ ______

-The crust for the continents is _______.

-Plates move apart at ___-______ ______.

--where new, ___ ______ is erupting.

----becoming _______ crust

-__________ ________ when plates collide.

Back 60

Plates; lithosphere; asthenosphere; lithospheric mantle; thicker; mid-ocean ridges; hot mantle; oceanic; convergent boundary

Front 61

Igneous rocks are ______ _____ that cooled down

Back 61

molten rocks

Front 62

The old oceanic crust got

Back 62

subducted

Front 63

*Continental Crust is ____ _____

-It's like a __________ ______.

-Continents ___ __________, _______ _______ _________, etc.

Back 63

less dense; floatation device; get stretched; pushed back together

Front 64

*Why is the Earth doing this?

-Earth is making the ____ ______ rock rise.

-Earth is a physical system trying to achieve ________.

-Plate tectonics is the Earth's way of ________ _____ ____.

-________

Back 64

less dense; coolness; cooling itself off; convecting

Front 65

*What defines a unit of plate?

-__________

- __________ ________ the ____

-_______ is moving as a _____ piece.

Back 65

Boundary; motion between; plates; plate; solid

Front 66

Some plates are entirely _______, others are made of both _______ and _______ ________.

Back 66

oceanic; oceanic; continental; lithosphere

Front 67

Active continental margins are

Back 67

plate boundaries

Front 68

_____ _____ are not plate boundaries

Back 68

passive margins

Front 69

Earthquakes occur in________ _________ that define tectonic plate boundaries.

Back 69

seismic belts

Front 70

Three types of plate boudaries

-Divergent:

-convergent:

-transform:

Back 70

plates move away, plates move toward, plate move past

Front 71

When continental lithosphere ______ and __, the upper crust breaks by _______. Upwelling asthenosphere initiates ___________. Rifting may _____ a _______ in ___.

Back 71

stretches, thins; faulting; volcanism; split; continent; two

Front 72

The East African rift is an _____ ____. The Red Sea started as a rift, but it evolved into a _______ _______ _______, the rift axis became a ___-____ _______.

Back 72

active rift; narrow ocean basin; mid-ocean ridge

Front 73

A _______ ___________ exists beneath the ridge axis. Molten rock that flows out onto the seafloor produces ______ _________. _______ ________ inject ______ the magma chamber. _________ forms at depth.

Back 73

magma chamber; pillow basalt; Basalt dikes; above; Gabbro

Front 74

____ still happen along the plates.

Back 74

Earthquakes

Front 75

The further away we get from the edges, the ____________ the Earthquakes are.

Back 75

deeper

Front 76

Continental collision starts _________ subduction.

Back 76

After

Front 77

Continental crust is ___ _________ to subduct, so ______ ________ develop.

Back 77

too buoyant; mountain ranges

Front 78

Sinking lithosphere is ____ going into the core, but is being ________ into the lower mantle.

Back 78

not; reabsorbed

Front 79

Hot material is ______ __, _________, and is _______ to the ______.

Back 79

coming up; crystallizes; pushed; sides

Front 80

______ is not exactly the boundary.

Back 80

Trench

Front 81

________ ________ scraped up

Back 81

Accretionary Prism

Front 82

In some cases, a volcanic island arc develops on a ______ ________ of ______ ________ that had split away from the main continent

Back 82

small fragment; continental crust

Front 83

*Transform faults

-happen a ton as part of the __-______ ________

-The mid-ocean ridge is much _________ than the deeper _______ _______. The ridge is offset along its length by transform fault _____ ________.

-Some transform boundaries ___ continental crust. For example, across the ___ _________ _________, the Pacific plate moves _________ relative to the ____ __________ _______.

Back 83

mid-ocean ridges; shallower; abysmal plains; fracture zones; San Andreas Fault; northwest; North American plate

Front 84

*Hot Spots

-Geologists recognize numerous hot-spot tracks ______ the _______.

-Probably a consequence of ______ ________

-Coming at least from ______ in the ________

-_______ of material

-a chain of _______ ___________ forms

-Hawaii

--Islands ______ in age with distance from the present hot spot.

--_____________ _________.

Back 84

around; world; mantle plume; deep; mantle; extinct volcanoes; increase; energetically favorable

Front 85

*How did we figure plate tectonics out?

-_______ ___________ (1925)

-Continents look like _______ _______

-_______

-_________ leave a telltale signature

-________ belts

-_________ belts

-He had no idea ___ they moved from each other

-Looked at ______

Back 85

Alfred Wegener; puzzle pieces; fossils; glaciers; mountain; climate; how; magnetism

Front 86

*Paleomagnetism

-The Geomagnetic Field has both _______ and _____

--_______

--________

-Rocks can acquire _______

--Cools and iron grains _____ with Earth's field

--________ wherever they are

-Geomagnetic pole _______ a bit (points mostly north)

-________ variation

-Geomagnetic field ________ every so often

--___________ ________

-had to have a ton of ______ to figure this out

--_____

Back 86

magnitude; direction; inclination; declination; magnetization; align; frozen; wanders; paleosecular; reverses; symmetric pattern; boats; WWII

Front 87

*Eight elements make up __% of the Earth's crust

-mostly ______

-Order of elements by amount

--_________

Back 87

90; oxygen; Oxsialfecanakmg

Front 88

*Oxygen is the only _____ (negatively charged)

-_______

- a lot of times, we're gonna put _______ with oxygen because there's a lot of _______

-_____________- a fundamental building block of ______ _______, the most common type of minerals

Back 88

anion; tetrahedron; silicon; silicon; silicatetetrahedron; silicate minerals

Front 89

_______ __________ constitute almost the entire crust and mantle of the Earth.

Back 89

Silicate Minerals

Front 90

*Silicate minerals with isolated tetrahedral __ ____ _______ any oxygens. Instead, they are bonded together by their _________.

-Examples include ______ and _____

-Acts as though it were its own ______

-Important to understand that properties we can observe are ________ into the _____ of what they are.

Back 90

do not share; cations; olivines; garnets; anion; woven; fabric

Front 91

* In single-chain silicates, ___ of the _____ _____ ________ are bonded together. The Si:O ration is _:_.

-example: _______

Back 91

two; three basal oxygens; 1; 3; pyroxenes

Front 92

Double-chain silicates are like __ ____ _____ that share oxygens where tetrahedral _____ yielding an Si:O ratio of _:_

-example: _______

Back 92

two single chains; touch; 2;7

Front 93

*______ ___________ share oxygens along the ______ of the tetrahedral, but not the oxygen at the ___ of the tetrahedral. The Si:O ratio is _:__

-Examples: _____ and _______ _________

Back 93

Sheet silicates; base; top; 4; 11; micas; clay minerals

Front 94

In framework silicates, all of the oxygens are ________ between _________ _____________, yielding an Si:O ratio of _:_

-most ____ packed

-Examples: _______ and _______-

Back 94

shared; adjacent tetrahedral; 1;2; densely; quartz; feldspar

Front 95

___________ ________ is mostly silicate minerals

Back 95

Oceanic crust

Front 96

Silicate minerals are classified by the

Back 96

anion

Front 97

*__________

-__________ __________ bonded to oxygen

--Ex. _________, __________, and ______

-________: metal cation bonded to a sulfide anion

--Examples: ______, ____________, and _________

-________: metal cation bonded to a sulfate anionic group

--Many of these form by ______ of _______

--ex:__________ (______) and ___________ (__________)

-_________: 2nd to right column

--Ex: _________ and _________

--tend to make ________

--breaks into _____

-_________

--ex: ______ and __________

--This is where the ________ in rocks go

-_________

--example: _______

Back 97

Oxides; metal cations; magnetite; hematite; rutile; sulfides; pyrite; galena; sphalerite; sulfates; evaporation; seawater; gypsum; hydrated; anhydrite; dehydrated; Hallides; halite; fluorite; salts; cubes; carbonates; calcite; dolamite; carbon; phosphates; apatite

Front 98

Pure masses of a single metal or non-metal

Back 98

native elements

Front 99

Name 4 native elements

Back 99

copper, gold, silver, sulfur

Front 100

Darrelhenryite

Back 100

new species of tourmaline named after a professor at LSU

Front 101

The types of minerals we find in the crust are ____________ than the ones in the mantle.

Back 101

different

Front 102

Volcanoes can be due to ______ of the plate.

Back 102

Subduction

Front 103

All things are

Back 103

spatially related.

Front 104

Crystals develop _________ from a central seed and grow to ______ ____________ ________. Existing crystals may act as _________, ________ growth in one or more directions

Back 104

outward; fill existing space; obstacles; restricting

Front 105

little bits (clasts) cemented together

Back 105

clastic rocks

Front 106

example of a clastic rock

Back 106

sandstone

Front 107

individual mineral crystals that grew up together

Back 107

crystalline rock

Front 108

example of crystalline rock

Back 108

granite

Front 109

come from magma or melt that is crystallizing

Back 109

igneous rocks

Front 110

bits of rock that broke off or eroded away cemented together

Back 110

sedimentary rock

Front 111

________ forms as a sedimentary rock.

Back 111

NOthing

Front 112

Come from temperature or pressure changes, used to be a different rock

Back 112

metamorphic rocks

Front 113

All rocks are born as ____ ______.

Back 113

igneous rocks.

Front 114

Back 114

Igneous Rocks; weathering and erosion; sedimentary rocks; heat and pressure; metamorphic rocks; melting; heat and pressure; weathering and erosion; melting

Front 115

Igneous rocks with really big grain size

Back 115

phanatic

Front 116

igneous rocks with tiny grains

Back 116

aphanatic

Front 117

igneous rocks with a mix of grain size

Back 117

porphyritic

Front 118

*Crystalline igneous rocks are classified by ______ and ________

Back 118

texture; composition

Front 119

Composition of igneous rocks

Back 119

felsic, intermediate, mafic, ultra mafic

Front 120

texture of igneous rocks

Back 120

fine, coarse, glassy

Front 121

*Glassy textures are most common in _______ __________ _________

Back 121

felsic igneous rocks

Front 122

frothy felsic rock full of vesicles that floats

Back 122

pumice

Front 123

glassy volcanic rock that fractures conchoidally

Back 123

obsidian

Front 124

glassy, vesticular mafic rock

Back 124

scorcia

Front 125

_________ ___________ are affected by how fast or slow they cool

Back 125

different textures

Front 126

Melts are mostly _______.

-___________

-Trace elements

--used as ______ later on

-Volatiles are also in melts

--anything that can be a ___

---H2O, CO2, SO2, N, He

-Can be from _ to __%

Back 126

silica; AlFeCaNaKMg; evidence; gas; 0; 15

Front 127

If you have a lot of silica, your melt will be ______.

Back 127

Felsic; Fe=Iron; Sic=Silica

Front 128

If you have a middle amount of silica, your melt will be

Back 128

intermediate

Front 129

If you have very little silica, your melt will be _________

Back 129

mafic; ma=magnesium, fic=iron

Front 130

If you've got a lot of Mg and Fe, your melt will be

Back 130

ultramafic

Front 131

Very low amounts of silica is still about

Back 131

40%

Front 132

realm where igneous rocks solidify above ground

Back 132

extrusive

Front 133

extrusive igneous rock

Back 133

basalt

Front 134

realm where igneous rocks solidify below ground

Back 134

intrusive

Front 135

Large grains took a _____ time to form

Back 135

long

Front 136

Two minerals in oceanic crust

Back 136

gabbro and basalt

Front 137

two minerals in continental crust

Back 137

rhyolite and granite

Front 138

Melting occurs when (3)

Back 138

temperature rises, pressure decreases, the solidus moves due to volatile content

Front 139

baseline (average) of normal planet, average change in temperature with depth

Back 139

geotherm

Front 140

condition at which rock completely melts

Back 140

liquidus

Front 141

conditions at which rock starts to melt

Back 141

solidus

Front 142

when do we move the solidus line?

Back 142

when there is a change in pressure or temperature

Front 143

Decompression melting takes place when the _______ acting on a hot rock ___________. When the pressure decreases a lot due to the rock rising, but the rock only cools a little, the rock begins to ____.

Back 143

pressure; decreases; melt

Front 144

Heat-transfer melting occurs when ________ _________ brings heat up with it and melts _______ or _______ rock.

Back 144

rising magma; overlying; surrounding

Front 145

Heat rising from magma _______ ___ ______

Back 145

melts the crust

Front 146

________ magma pools at the base of the crust

Back 146

basaltic

Front 147

To melt it means that something is moving _____ enough that it is not on the geotherm

Back 147

fast

Front 148

Decompression melting can occur (3)

Back 148

in a mantle plume, beneath a rift, and beneath a mid-ocean ridge

Front 149

In Flux melting, common volatiles include ___ and ___. These substances are brought into _________ ________ in sediment and fractures in the subducting crust.

Back 149

H2O and CO2; subduction zones

Front 150

Flux melting occurs where __________ enter ___ ____; this happens at ____ zones.

Back 150

volatiles, hot mantle; subduction

Front 151

At a mantle plume or hot spot, there will be ____ ________ or ________ melting because we are _____ __ what's already there.

Back 151

heat transfer; decompression; heating up

Front 152

At a subduction zone there will be ____ and ____ _______ melting. Examples of what will be found there are _____ ______ and ________ stuff.

Back 152

Obsidian glass; extrusive

Front 153

At a mid-ocean ridge, there will be ________ and _____ melting because ________ circulates and can change physical properties. Examples of what can be found there are ___________ and _____.

Back 153

decompression; flux; seawater; basalt; gabbro

Front 154

At a continental rift there will be ______ and ____ ________ melting.

Back 154

decompression; heat transfer

Front 155

Coarse-grained rocks are _______.

Back 155

intrusive

Front 156

Granite is (3)

Back 156

more felsic, has more silicate, can be under subduction zones

Front 157

Back 157

Crystalline; Fine; Coarse; felsic; intermediate; mafic; ultramafic; rhyolite; andesite; basalt; komatilite; granite; diorite; gabbro; peridotite; quartz; Na; Biotite; Plagioclase; Amphibole; Ca; Pyroxene; Olivine

Front 158

*Bowen's reaction series

-A ____ melt starts to cool.

-_________ and __-rich ______ starts to sink

-If the residual melt escapes and freezes, it produces ___ _____.

-_______ starts to form, and _______ contains more __.

-With decreasing temperature, _______ __________ begins and the composition of the remaining magma becomes more _______.

-The rocks change as the ______ and the _____ change.

_____ minerals _________ first, at highest temperature. The last minerals to crystallize are _____, __________ and ___________.

Back 158

mafic; olivine; Ca; plagioclase; felsic rock; Pyroxene; plagioclase; Na; fractional crystallization; felsic; mafic; crystallize; quartz; muscovite; and k-feldspar

Front 159

In intrusive settings, magma invades preexisting ____ ____ by percolating upward _______ ______, wedging ____ ______, melting and breaking off bloacks of wall rock.

Back 159

wall rock; between grains; open cracks

Front 160

Xenoliths and plutons

Back 160

chunks of wall rock incorporated into the magma

Front 161

Plutons may intrude by _______. When blocks of wall rock fall into the magma, some ________ but others may remain as ________.

Back 161

stoping; dissolve; xenoliths

Front 162

fill space formed when crust undergoes horizontal stretching

Back 162

dikes

Front 163

intrude between layers and may cause the uplift of the land surface

Back 163

sills

Front 164

typify extrusive behavior of high viscosity felsic magmas

Back 164

explosive ash eruptions

Front 165

deadly avalanches of superheated volcanic ash and debris

Back 165

pyroclastic flows

Front 166

Pyroclastic flows race down volcanic slopes as a ________ _________ moving on a carpet of ___ ____. Thick layers of volcanic tuff ________ from explosive eruption.

Back 166

density current; hot air; accumulate

Front 167

Back 167

dike; sill; dike; sandstone; sill

Front 168

The conditions leading up to decompression melting occur in several geologic environments. In each case, a volume of ___ _____________ rises to a _________ _______ and ______ forms.

Back 168

hot asthenosphere; shallower depth; magma