Deck 11: Crustal Deformation and Mountain Building

Question 1

A horst is .

A)an uplifted block bounded by two reverse faults
B)an uplifted block bounded by two normal faults
C)a downdropped block bounded by two normal faults
D)a downdropped block bounded by two reverse faults

Answer 1

B

Question 2

A good example of a present- day, passive continental margin is the .

A)east coast of North America
B)east coast of the Japanese Islands
C)north flank of the East Pacific Rise
D)west coast of South America

Answer 2

A

Question 3

A graben is characterized by .

A)a hanging wall block that has moved down between two normal faults
B)a footwall block that has moved down between two reverse faults
C)a footwall block that has moved up between two normal faults
D)a hanging wall block that has moved up between two reverse faults

Answer 3

A

Question 4

A transform fault is _ .

A)a strike- slip fault that forms the boundary between tectonic plates
B)a reverse fault that steepens into a thrust fault
C)the rift bounding faults on a mid- ocean ridge
D)a dip- slip fault connecting an anticline with a syncline

Question 5

A(n)fault develops in response to horizontal, tensional stresses in crustal rocks.

Question 6

The term refers specifically to geologic mountain building.

A)orogenesis
B)orogneisses
C)orthogeny
D)orthogonal

Question 7

Large circular downwarped structures are called .

A)anticlines
B)basins
C)domes
D)synclines

Question 8

A(n)fault has little or no vertical movements of the two blocks.

A)dip slip
B)stick slip
C)strike slip
D)oblique slip

Question 9

Tensional forces normally cause which one of the following?

A)reverse faults
B)thrust faults
C)normal faults
D)strike- slip faults

Question 10

The concept that rocks of the crust and upper mantle are floating in gravitational balance is known as .

A)isomonism
B)isobration
C)isostasy
D)isotropy

Question 11

Which one of the following is an example of an isostatic movement?

A)arching of strata at the center of a dome
B)numerous aftershocks associated with deep- focus earthquakes
C)uplift of areas recently covered by thick, continental ice sheets
D)stream downcutting following a drop in sea level

Question 12

The mountains and valleys of the Basin and Range Province of the western United States formed in response to .

A)strike- slip faulting and hanging wall block uplifts
B)reverse faults and large displacement, thrust faulting
C)normal faulting and horizontal compression
D)tensional stresses and normal- fault movements

Question 13

The Black Hills of South Dakota are a good example of a(n).

A)anticline
B)dome
C)basin
D)syncline

Question 14

A thrust fault is best described as _ .

A)a vertical, normal fault
B)a steeply inclined, oblique- slip fault
C)a low- angle, reverse fault
D)a near vertical, strike- slip fault

Question 15

The are a geologically old mountain range folded and deformed during the Paleozoic.

A)Cascades in the northwestern United States
B)Appalachians in the eastern United States
C)Rockies in the western United States
D)Alps in Europe

Question 16

In thrust faulting, .

A)horizontal, tensional stresses drive the deformation
B)grabens develop on the footwall block
C)the crust is shortened and thickened
D)the hanging wall block slips downward along the thrust fault

Question 17

The in California is the boundary between the North American and Pacific plates.

A)San Luis Obispo thrust fault
B)Sierra Nevada frontal fault
C)San Andreas strike- slip fault
D)San Francisco normal fault

Question 18

In a normal fault _.

A)the hanging wall block below an inclined fault plane moves downward relative to the other block
B)the footwall block above an inclined fault plane moves upward relative to the other block
C)the hanging wall block above an inclined fault plane moves downward relative to the other block
D)the footwall block below an inclined fault plane moves downward relative to the other block

Question 19

A(n)is a thick accumulation of sediments and small, tectonic blocks formed of material scraped off a descending, lithospheric plate.

A)continental shelf, terrain complex
B)mass movement complex
C)subterranean- accumulation complex
D)accretionary- wedge complex

Question 20

Folded limestones that occur high in the Himalayas were originally deposited as sediments in a .

A)late Paleozoic syncline north of the Tibetan Plateau
B)deep ocean trench along the southern margin of India
C)marine basin between India and Eurasia
D)Cenozoic fault basin between Africa and Arabia

Question 21

Any accreted crustal fragment that has a geologic history distinct from that of the adjoining fragments is termed a(n).

Question 22

Are horsts and grabens bounded by normal or reverse faults?

Question 23

The east coast of North America is a good example of a(n)tectonic margin.

Question 24

A region is characterized by numerous anticlines and synclines. There are also several faults present that appear to have formed at the same time as the folding. Without looking at any details, what type of faults would you assume them to be? Why?

Question 25

Fault- block mountains occur in regions dominated by faulting.

Question 26

In a thrust fault, the hanging wall moves _ relative to the footwall, and the fault plane is oriented at a(n)angle.

Question 27

are fractures showing little or no movement of the rocks on either side.

Question 28

The mountains in North America were formed by a continent- continent collision in the Paleozoic.

Question 29

A circular to elliptical structure developed by upward arching of the central strata is a(n)
.

Question 30

A circular to elliptical structure developed by downwarping of the central strata is a(n)
.

Question 31

A fault is observed in a road cut, but there are no obvious rocks units to correlate on either side of the fault to determine relative movement. How else might you determine or even infer whether the hanging wall has moved up or down relative to the footwall? (Hint: Think of fossils, tectonic setting, etc.)

Question 32

Describe the characteristics of regions dominated by fault- block mountains such as the Basin and Range. What is their relationship to plate tectonics and why don't they create large- scale areas of orogenesis like
Andean- Type margins or continental collisions?