Geology 101 Quiz 2

Question 1

if any plate moves, it must immediately (3 things)

Answer 1

1. run into another plate in the direction it is moving
2. pull away from a plate on the opposite side
3. grind laterally past plates on the sides

Question 2

three types of tectonic boundaries or zones

Answer 2

divergent, convergent, transform fault

Question 3

divergent boundaries

Answer 3

where two plates pull apart

Question 4

convergent boundaries

Answer 4

where two plates collide

Question 5

transform fault boundaries

Answer 5

where to plates slide past one another

Question 6

divergent boundaries will occur

Answer 6

above rising convection cells

Question 7

convergent boundaries will occur

Answer 7

where convection cells are falling downward

Question 8

when plates pull apart (divergence), what happens?

Answer 8

magma from the mantle fills the gap and creates new oceanic crust

Question 9

when plates collide (convergence), what happens?

Answer 9

plates will either crumple, or one plate will slide beneath the other, a process known as subduction

Question 10

plates sliding past one another (transform faults) form ?

Answer 10

fault zones

Question 11

the appearance of the surface of the earth is controlled in large part by

Answer 11

the type of tectonic boundaries present, and whether the plate boundary is oceanic or continental

Question 12

examples of oceanic-oceanic plate divergent boundaries

Answer 12

mid-atlantic ridge, east pacific rise

Question 13

oceanic-oceanic plate divergent boundaries feature

Answer 13

elevated ridge on ocean floor, earthquake activity common, sea floor lava flows, thermal vents (super heated water)

Question 14

the mid-atlantic ridge falls exactly in the middle of

Answer 14

the Atlantic between North/South America and Europe/Africa

Question 15

the mid-atlantic ridge divergent zone passes through Iceland, which is a good example of

Answer 15

divergence in continental crust

Question 16

continental-continental plate divergent boundaries examples

Answer 16

Iceland, Great Rift Valley (Africa)

Question 17

continental-continental plate divergent boundaries feature

Answer 17

elevated ridge with rifted valley; earthquake activity common; lava flows; narrow, inland seas

Question 18

Iceland periodically loses a town to

Answer 18

lava flows emanating from rifts

Question 19

Great Rift Valley (East African Rift) is actually a

Answer 19

three pointed star-shaped rift

Question 20

the ? and the ? are rifts filled in with water (narrow inland seas)

Answer 20

Red Sea, Gulf of Aden

Question 21

continental-oceanic plate divergent boundaries are not seen because

Answer 21

oceanic crust is generated on either side of the rift, so it readily turns into an oceanic-oceanic plate boundary

Question 22

continental-oceanic plate convergent boundaries examples

Answer 22

Pacific Northwest (Mt. St. Helens area), Andes Mountains/Peru-Chile Trench

Question 23

continental-oceanic plate convergent boundaries feature

Answer 23

volcanic mountains on continental parallel to coast, subduction of oceanic plate - creates ocean trench parallel to coast, deep earthquakes from subducting plate

Question 24

when oceanic crust meets continental crust, which always loses and why?

Answer 24

oceanic crust (it’s thinner and sits lower)

Question 25

friction from ? plates generates tremendous heat; overlying rock material melts and moves upward and ?

Answer 25

subducting; erupts as volcanoes

Question 26

when subduction begins, the downward bend results in

Answer 26

a deep trench

Question 27

the trenches from subduction form the

Answer 27

deepest places on earth (some are under nearly 7 miles of water, which is much deeper than Mount Everest is tall)

Question 28

volcanic mountains typically form directly above

Answer 28

the subducting plate

Question 29

Mt. St. Helens and Mt. Rainier are active volcanoes because of

Answer 29

subduction of the Juan de Fuca Plate

Question 30

oceanic-oceanic plate convergent boundaries examples

Answer 30

Japan, Aleutian Islands, Philippines

Question 31

oceanic-oceanic plate convergent boundaries feature

Answer 31

volcanic island arc, ocean trench parallel to island arc, deep earthquakes from subducting plate

Question 32

subduction of one plate produces

Answer 32

volcanism and island building

Question 33

the perimeter of the Pacific is known as the "Ring of Fire" because

Answer 33

its lined with earthquake epicenters and volcanoes

Question 34

continental-continental plate convergent boundaries examples

Answer 34

Himalaya Mountains

Question 35

continental-continental plate convergent boundaries feature

Answer 35

non-volcanic mountains (inland), lots of earthquakes

Question 36

the ? are the tallest mountains in the world because of ?

Answer 36

Himalayas; active collision and buckling of two colliding continental plates

Question 37

continental-continental plate transform fault boundaries examples

Answer 37

San Andres Fault, California

Question 38

continental-continental plate transform fault boundaries feature

Answer 38

strike-slip faults, shallow earthquake activity

Question 39

strike-slip faults

Answer 39

faults with no vertical displacement (both sides move horizontally)

Question 40

oceanic-oceanic plate transform fault boundaries examples

Answer 40

Mid-Atlantic Ridge, East Pacific Rise

Question 41

oceanic-oceanic plate transform fault boundaries feature

Answer 41

strike-slip faults, shallow earthquake activity

Question 42

continental-oceanic plate transform fault boundaries

Answer 42

not seen b/c oceanic crust sits lower and is thinner; since lateral movement is never perfectly parallel, the weaker oceanic plate quickly starts to subduct; it thus becomes a convergent zone

Question 43

Hot Spots

Answer 43

relatively stationary areas of the mantle that are particularly hot, which periodically melt through the overlying crust to produce a volcano

Question 44

Hot Spots examples

Answer 44

Hawaii; Yellowstone National Park, Wyoming

Question 45

Hot Spots feature

Answer 45

mid-plate volcanism

Question 46

because the overlying plate is moving, the periodic volcanism of hot spots results in

Answer 46

a string of volcanoes that get older the farther they are from the current volcanic activity

Question 47

number of plates (are/are not) fixed

Answer 47

are not

Question 48

oceanic plates (can/cannot) disappear

Answer 48

can (if two continents approach each other and collide, the ocean that was between them will completely subduct and disappear)

Question 49

continents (do/do not disappear), they (are/are not) buoyant

Answer 49

do not; are (when continents collide, they become a single land mass)

Question 50

new plates can form by

Answer 50

breaking existing plates

Question 51

continents (can/cannot) grow

Answer 51

can (islands that form and later collide with a continent add additional land to the continent; the islands will not subduct)

Question 52

What evidence did Alfred Wegener see that continents have drifted over time?

Answer 52

1. "Jig saw puzzle" fit of continents 2. rock types and fossil types on different continents matched 3. the presence of glacial deposits and glacial scrape marks on all the continents that all grouped together if the continents were put together

Question 53

none of Wegener's observations were convincing enough until ?

Answer 53

reversals were discovered in seafloor magnetism

Question 54

when iron-bearing magma solidifies (hardens into rock), the iron minerals ...

Answer 54

align along the earth's magnetic field

Question 55

the earth's magnetic field (has/has never) reversed

Answer 55

has (and many times)

Question 56

we can tell the earth's magnetic field has reversed because

Answer 56

successive lava flows on the same volcano will have iron minerals oriented in one direction in one flow, and reversed in the opposite direction in a later flow

Question 57

bands run (parallel/perpendicular) to mid-ocean ridges with reversing magnetic orientation

Answer 57

parallel

Question 58

stations set up around the world have documented that the distance between Europe and North America

Answer 58

increases by several centimeters each year