Geology 131 Study Guide Ch10 Deformation, Mountain Bldg, Continents

Front 1

What is the term for all changes in shape and/or volume of rocks?

Back 1

Deformation

Front 2

What is the term for force applied to given area of rock?

Back 2

Stress

Front 3

What is the general term for deformation caused by forces acting on rocks?

Back 3

Strain

Front 4

What is the term stress where forces are directed toward one another?

Back 4

Compression

Front 5

What is the term for stress where forces are directed away from one another?

Back 5

Tension

Front 6

What is the term for stress where forces are parallel but act in opposite directions?

Back 6

Shear

Front 7

What is the term for deformation where rocks regain original shape when stress is gone?

Back 7

Elastic

Front 8

What is the term for deformation where rocks are permanently folded?

Back 8

Plastic

Front 9

What is the term deformation where rocks break?

Back 9

Brittle

Front 10

What is the term for rocks that tend to bend more before they break?

Back 10

Ductile

Front 11

What is the term when features in rocks are bent

Back 11

Fold

Front 12

What is the term a fracture without movement across it?

Back 12

Joint

Front 13

What is the term a fracture along which movement occurs?

Back 13

FAult

Front 14

What is the term for an episode of mountain building with intense deformation?

Back 14

Orogeny

Front 15

What is the principle that EArth's crust is in floating equilibrium with denser mantle?

Back 15

Isostacy

Front 16

What is the general term used to describe force per unit area?

Back 16

Stress

Front 17

What does stress create in rocks?

Back 17

1. strain or
2. deformation

Front 18

Name the 3 forces important in geology?

Back 18

1. Tension
2. Compression
3. Shear

Front 19

What is the term for a fold with the oldest layers in the core?

Back 19

Anticline or dome

Front 20

In an anticline or dome, in what direction will the layers point?

Back 20

The layers will dip into or towards the center

Front 21

What happened to the crust of the Basin and Range Province?

Back 21

It was stretched and thinned.

Front 22

What caused the crust of the Basin and Range Province to stretch and thin?

Back 22

1. Normal faults and
2. Tensional stress

Front 23

What do mountains formed during oorgenies show?

Back 23

1. Intense deformation
2. Metamorphism
3. Folds
4. Reverse or thrust faults

Front 24

From west to east, the Andes are made of what type of wedge?

Back 24

Accretionary wedge

Front 25

What type of volcanoes are in the Andes from west to east?

Back 25

Andesitic volcanoes

Front 26

What type of sedimentary rocks are contained in the Andes?

Back 26

Folded and Reverse/Thrusted Sedimentary Rocks

Front 27

What are the 3 causes for joint forming?

Back 27

1. Compression
2. Tension
3. Shear stress

Front 28

What do melting of glaciers and the erosion of mountains cause?

Back 28

Isostatic rebound of the crust

Front 29

Where will the oldest rocks in a dome be?

Back 29

Inside of the fold

Front 30

Where will the oldest rocks in a basin be?

Back 30

Outside or edges of the fold

Front 31

List the features formed along faults:

Back 31

1. scratches or polish on the fault plane;
2. fault breccia
3. offset of sedimentary layers on either side of the fault

Front 32

What will tensional stress cause rocks to do?

Back 32

Thin

Front 33

Name 4 characteristics of ductile behavior:

Back 33

1. found in mudstones
2. when rocks bend before they break
3. more common deep in the Earth's crust
4. more likely if stress is applied slowly

Front 34

What do strike and dip measure?

Back 34

The orientation of inclined planes in space

Front 35

A fold with a horizontal axial plane is what kind of fold?

Back 35

Recumbent fold

Front 36

What type of behavior is the formation of joint an example of?

Back 36

Brittle behavior

Front 37

List 4 results of compressional stress:

Back 37

1. thrust fault
2. fold
3. anticline
4. reverse fault

Front 38

What is the term for a fault where the hanging wall block moves up relative to the footwall?

Back 38

Reverse fault

Front 39

Name 4 features of geologic maps:

Back 39

1. help asses volcanic hazards
2. summarize a great deal of geologic information
3. assist in zoning decisions
4. help plan locations of dams

Front 40

Name 4 physical structures formed during orogenies:

Back 40

1. mountains
2. uplift of marine sediements far above sea level
3. recumbent folds
4. thrust faults

Front 41

Name 4 characteristics of accreted terranes:

Back 41

1. add to the width of a continent
2. were oceanic topographic features
3. are scraped off ocean plates during subduction
4. have very different rocks and fossils from the rocks around them

Front 42

What are the most common geologic structures?

Back 42

Joints

Front 43

What causes horst and graben topography?

Back 43

Multiple normal faults

Front 44

Where is the thickest crust found?

Back 44

Along Continental Mountain Ranges

Front 45

What does the Principle of Isostacy explain?

Back 45

Why continent crust stands higher than ocean crust

Front 46

When huge quantities of water are trapped behind a dam, what explains why the crust underneath sinks?

Back 46

Isostacy

Front 47

Even if an anticline is eroded so it does not show an arch shape, why can it still be recognized?

Back 47

The oldest rocks will be in the middle around the axial plane

Front 48

What geologic structure looks most like a bulls-eye?

Back 48

An eroded dome

Front 49

What are fault scarps?

Back 49

Exposures of the fault plane itself

Front 50

What 4 characteristics of NOrth America?

Back 50

1. Is made jup of lots of accreted terranes
2. has been tectonically active for millions of years
3. is an orogenic belt
4. has evidence of active volcanoes in California in the past

Front 51

How did the Teton Mountain Range form?

Back 51

Tension

Front 52

What is deformation of rocks?

Back 52

A change in shape and or volume of the rock

Front 53

How do continents grow?

Back 53

Accretion

Front 54

What is the term for force per area?

Back 54

Stress

Front 55

What will compression cause rocks to do?

Back 55

Thicken

Front 56

What will happen to rocks stressed beyond their elastic limit?

Back 56

They will deform permanently

Front 57

Which of the following is a geographic feature but NOT strictly a type of geologic structure:
1. syncline
2. fault zone
3. mountain range
4. fold
5. monocline

Back 57

3. mountain range

Front 58

T or F
Rocks layers that are not horizontal have been deformed.

Back 58

TRUE

Front 59

List the 4 ways geologists describe folds:

Back 59

1. shape
2. axial plane orientation
3. plunging or non-plunging
4. circular or non-circular

Front 60

How do faults differ from joints?

Back 60

Rocks on either side of the fault are offset parallel to the fracture

Front 61

How could you tell a reverse fault from a normal fault?

Back 61

The reverse fault moves the hanging wall up.

Front 62

T or F
Rocks can resist compressional forces better than tension.

Back 62

TRUE

Front 63

T or F
Deformation refers to changes in the shape and/or volume of the rock and is also called "stress".

Back 63

FALSE

Front 64

T or F
Anticlines and synclines are rarely found together.

Back 64

FALSE

Front 65

T or F
Anticlines commonly form structural traps for oil.

Back 65

TRUE

Front 66

T or F
The highest mountains on EArth are less than 90000 meters above sea level.

Back 66

TRUE

Front 67

T or F
The longest mountains on Earth are under the oceans.

Back 67

TRUE

Front 68

T or F
Accreted terranes and accretionary wedges are exact synonynms.

Back 68

FALSE

Front 69

T or F
Mountains always form at the edges of continents where the active margins are.

Back 69

FALSE

Front 70

T or F
The pull of gravity varies from place to place.

Back 70

TRUE

Front 71

T or F
Ductile behavior is only possible under the tremendous pressures and temperatures of the mantle.

Back 71

FALSE