Chapter 11, test 2: crustal deformation adn mountain building

Question 1

deformation

Answer 1

a general term that refers to all changes in the original form and/or size of a rock body.

Question 2

stress

Answer 2

the forces that deform rock

compressional stress, and tensional stress

Question 3

compressional stress

Answer 3

stress that squeezes and shortens rock mass

Question 4

tensional stress

Answer 4

stress that pulls apart or elongates a rock mass

Question 5

elastic deformation

Answer 5

like a rubber band the rock will return to nearly its original size and shape when stress is removed

Question 6

brittle deformation

Answer 6

when the limit of rock strength is surpassed the rock fractures
low temp

Question 7

ductile deformation

Answer 7

solid state flow (like water or taffy) that produces a change in shape without fracturing.
high temp

Question 8

factors that influence the strength of a rock

Answer 8

temperature
confining pressure
rock type
time

Question 9

temperature

Answer 9

high temp causes ductile deformation

low temp causes brittle deformation

Question 10

confining pressure

Answer 10

greater pressure causes ductile deformation

Question 11

rock type

Answer 11

sedimentary rocks and foliated metamorphic rocks deform by ductile deformation.
igneous tend to deform by brittle deformation

Question 12

time

Answer 12

when techtonic forces are applied slowly over a long time, rocks display ductile deformation

Question 13

folds

Answer 13

rocks bent in a series of waves
most folds result form compressional forces that shorten and thicken crust
types: anticline, syncline

Question 14

anticline

Answer 14

up folded or arched rock layers

Question 15

syncline

Answer 15

down folded rock layers

Question 16

symmetrical

Answer 16

limbs mirror images

Question 17

asymmetrical

Answer 17

limbs are not mirror images

Question 18

overturned

Answer 18

one limb is tilted beyond the vertical

Question 19

faults

Answer 19

fractures or breaks in rocks along which appreciable displacement has taken place

Question 20

dip slip fault

Answer 20

movement along the inclination (dip) of fault plane

2 types: normal and reverse/thrust

Question 21

hanging wall

Answer 21

the rock above the fault surface

Question 22

footwall

Answer 22

the rock below the fault surface

Question 23

normal dip slip fault

Answer 23

hanging wall moves down
associated with fault block mountains
caused by tensional forces <>

Question 24

reverse dip slip fault

Answer 24

hanging wall moves up
caused by compressional stress ><
dips greater than 45 degrees

Question 25

thrust dip slip fault

Answer 25

hanging wall moves up caused by compressional stress >< dips less than 45 degrees

Question 26

megathrust earthquakes

Answer 26

due to shallow dip of the plate boundary large sections tend to get stuck these are most powerful earthquakes, a lot of tension builds up

Question 27

strike slip fault

Answer 27

slide past each other dominant displacement in horizon often associated with plate boundaries

Question 28

joints

Answer 28

fractures along with no appreciable displacement has occurred (no movement) example is arches national park

Question 29

orogenesis

Answer 29

refers to processes that collectively produce mountain belts | example: laramide orogeny produced the rocky mountains

Question 30

continental volcanic arc

Answer 30

oceanic-continental crust convergence

Question 31

volcanic island arcs

Answer 31

oceanic-oceanic crust convergence

Question 32

continental collisions

Answer 32

continental-continental crust convergence