Lesson 3: Deformation of the crust

Question 1

forces tending to compress, pull apart or deform a rock

Answer 1

stress

Question 2

squeezing, decreased volume
plates moving together (type of stress force)

Answer 2

compressive stresss

Question 3

stretching, increased volume
plates moving apart (type of stress force)

Answer 3

tensional stress

Question 4

change in shape
plates sliding past each other (type of stress force)

Answer 4

shear stress

Question 5

adjustment to stress

Answer 5

strain

Question 6

returns to original shape (strain type)

Answer 6

elastic strain

Question 7

• molded or bent
• do not return to original shape (strain type)

Answer 7

plastic strain

Question 8

rock cracks or breaks (strain type)

Answer 8

fracture strain

Question 9

note: when drawing types of stresses, it is just one rock for compression, and tension. shearing looks like plate boundaries

Answer 9

if u remember, then nice

Question 10

note: when drawing types of stresses, it is just one rock for compression, and tension. shearing looks like plate boundaries

Answer 10

if u remember, then nice

Question 11

amount of force per unit area on a given material

Answer 11

stress

Question 12

The process by which the shape of a rock changes in response to stress is called _____

Answer 12

deformation

Question 13

defined as a bend in rock that is the response to
compressional forces
Most visible in rocks that have layering

Answer 13

fold

Question 14

For plastic deformation to happen, there are lotsa factors. One is: pressure must not exceed the internal strength of the rock. If it does, ______occurs

Answer 14

fracturing

Question 15

resulting deformation

Answer 15

strain

Question 16

cause of deformation

Answer 16

stress

Question 17

types of deformation
recoverable, small amounts of strain, doesn’t happen to rocks

Answer 17

Elastic

Question 18

types of deformation
permanent; rocks flow as movement occurs along small structural defects.

Answer 18

Plastic

Question 19

types of deformation
rock moves in opposite directions on either side of a break

Answer 19

rupture

Question 20

what are the two main types of deformation?

Answer 20

Deformation by flow
Brittle deformation

Question 21

site where rocks are exposed at the surface (honestly, this probs won’t appear in the exam)

Answer 21

outcrop

Question 22

the angle of inclination of the bedding surface down off the horizontal

Answer 22

Dip

Question 23

the trend or direction of the strata or the bearing of any horizontal line on the plane perpendicular to the direction of dip

Answer 23

Strike

Question 24

– wavelike undulations caused by bending of rocks usually produced by horizontal compressive stresses
– occurs at great depths inside the Earth under great temperatures and pressures

Answer 24

folds (2nd definition)

Question 25

a plane through a rock fold that includes the axis-divides the fold as symmetrically as possible

Answer 25

Axial plane

Question 26

the ridge or place of sharpest folding

Answer 26

axis

Question 27

1 of 2 parts of the fold-on either side of axis

Answer 27

limb

Question 28

angle that fold axis makes with the horizontal

Answer 28

plunge

Question 29

types of folds: arching or upwarping of rock layers

Answer 29

anticline

Question 30

types of folds: down warping of rock layers

Answer 30

Syncline

Question 31

types of folds: double flexure of rock layers

Answer 31

Monocline

Question 32

types of folds: non-linear, anticlinal fold-beds dip away from central area in all directions

Answer 32

dome

Question 33

types of folds: non - linear, synclinal fold-beds dip towards central area from all directions

Answer 33

basin

Question 34

dips of opposite limbs of fold are approximately equal

Answer 34

symmetrical

Question 35

asymmetrical fold with one limb tilted beyond vertical

Answer 35

Overturned

Question 36

overturned fold with a horizontal axis

Answer 36

Recumbent

Question 37

axis of fold penetrates into ground

Answer 37

Plunging

Question 38

breaks in rock mass with no appreciable relative movement of rocks on opposite sides of break

Answer 38

Joints

Question 39

breaks in rock mass where appreciable movement of rocks on opposite sides of the break has occurred

Answer 39

faults

Question 40

block of rock immediately above fault surface

Answer 40

hanging wall

Question 41

block of rock immediately below fault surface

Answer 41

Footwall

Question 42

a fold in which the oldest rock layers are in the center of the fold

Answer 42

anticline

Question 43

a fold in which the youngest rock layers are in the center of the fold

Answer 43

syncline

Question 44

develops if the center of the fold moves from being once vertical to a horizontal position

Answer 44

recumbent fold

Question 45

Extreme stress and pressure can sometimes cause the rocks to shear along a plane of weakness creating a

Answer 45

fault

Question 46

combination of a fault and a fold

Answer 46

overthrust fold

Question 47

up or down movement of two blocks

Answer 47

dip-slip faults

Question 48

for drawing

Answer 48

when drawing right lateral transform faults, the top will be the one leaning towards the right side

Question 49

deformation in the crust can either be ______ or ______

Answer 49

abrupt or gradual (creep)

Question 50

sloping sides of a fold

Answer 50

limbs

Question 51

bend where the two limbs meet

Answer 51

hinge

Question 52

occur when tensional forces act in opposite directions and cause one slab of the rock to be displaced up and the other slab down

Answer 52

normal

Question 53

On a graben fault causes

Answer 53

rift valleys