Ch2

Question 0

New oceanic crust and lithosphere are formed at

Answer 0

Divergent boundaries by submarine eruptions and intrusions of basaltic magma

Question 1

The ___ are a logical evolutionary a analog of the Africa rift valleys ten million years from now

Answer 1

Red Sea

Question 2

Volcanoes and deep valleys of east Africa are related to a

Answer 2

Continental rift along which parts of the African continent are beginning to slowly separate

Question 3

Which if the following most accurately describes the volcanoes of the Hawaiian islands

Answer 3

Shield volcanoes fed by a long lived hot spot below the pacific lithospheric plate

Question 4

The temperature below which magnetic material can retain a permanent magnetization is called the

Answer 4

Curie point

Question 5

The Aleutian Islands occur at a

Answer 5

Convergent boundary on a volcanic arc above a northward subducting Pacific plate

Question 6

The__ is an example of an active, continent-continent collision

Answer 6

Northward movement of India into Eurasia

Question 7

Deep focus earthquakes are associated with___ plate boundaries.

Answer 7

Convergent (subducting)

Question 8

A transform plate boundary is characterized by ___

Answer 8

A deep, vertical fault along which two plates slide past one another in opposite directions

Question 9

A typical rate of seafloor spreading in the Atlantic Ocean is

Answer 9

2 cm per year

Question 10

A very long lived magma source located deep in the mantle is called a ___

Answer 10

Hot spot

Question 11

All of following contribute evidence supporting the theory if plate tectonics except for __

Answer 11

Changes in the moons orbit due to shifting plates

Question 12

Deep ocean trenches are surgical evidence for ___

Answer 12

Sinking of oceanic lithosphere into the mantle at a subduction zone

Question 13

Deep ocean trenches are most abundant around the rim of the ___ ocean basin

Answer 13

Pacific

Question 14

Cooler, older, oceanic lithosphere sink into the mantle at ___

Answer 14

Subduction zones along convergent plate boundaries

Question 15

The continental drift hypothesis was rejected primarily because Alfred Wegener could not ___

Answer 15

Identify a mechanism capable of moving continents

Question 16

Pull apart, rift zones are generally associated with

Answer 16

Divergent plate boundary

Question 17

Linear, magnetic patterns associated with mid ocean ridges are configured as

Answer 17

Normal and reversed magnetized strips roughly parallel to the ridge

Question 18

Which one of the following is an important fundamental assumption underlying the are tectonic theory

Answer 18

Earths diameter has been essentially constant over time

Question 19

___ plate boundaries have the larger magnitude earthquakes

Answer 19

Transform and convergent

Question 20

In the early part of the 20th century, ___ argued forcefully for continental drift

Answer 20

Alfred Wegener

Question 21

On average, lithospheric plates ___ thick

Answer 21

100km

Question 22

Where would you drill to recover samples of the oldest basalts of the oceanic crust, which are Jurassic in age?

Answer 22

Oceanic side of the Aleutian trench, along the southern coastline of Alaska

Question 23

___ most effectively outlines the edges if the lithospheric plates

Answer 23

Iines of earthquake epicenters

Question 24

___ first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid ocean ridge

Answer 24

Vine and Matthews

Question 25

The ___ were formed in the late Paleozoic when sediments in a marine basin were squeezed and crumpled between converging continents

Answer 25

Urals in Russia

Question 26

Mount St. Helens and the other cascade volcanoes are ___

Answer 26

Young, active volcanoes built on a continental margin above a sinking slab of oceanic lithosphere

Question 27

T or f: during the geologic past, the magnetic poles have generally been very close to earths geographical poles

Answer 27

True

Question 28

In general, rocks of the continental crust are less dense than rocks of the oceanic crust

Answer 28

True

Question 29

In general, seafloor sediments gradually thicken away from a mid ocean ridge

Answer 29

True

Question 30

As the south Atlantic basin widens by seafloor spreading, Africa and South America are moving closer together

Answer 30

False