IV. Question (75-100) Flashcards

1
Q

_______ makes plates move from spreading centers.
a) Slab pull
b) The asthenosphere
c) Ridge push
d) The lithosphere
e) nota

A

c) Ridge push

Ridge push is a tectonic force that drives plates away from mid-ocean ridges where new crust is formed. The elevated position of the ridge causes gravity to push the newly formed lithosphere away from the ridge axis, contributing to plate movement.

Slab pull primarily moves plates at subduction zones.
The asthenosphere is a ductile layer, but it doesn’t actively push plates.
The lithosphere itself is the rigid outer layer of the Earth.
Therefore, the correct answer is Ridge push.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Stress has ____ point components.
a) 6
b) 9
c) 3
d) 12
e) nota

A

b) 9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Based on the given log A, what type of fault likely caused the stratigraphy:
a. Sinistral fault
b. Dextral fault
c. Thrust fault
d. Normal fault
e. None of the above

A

c. Thrust fault

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

_______is responsible for the stratigraphy depicted in Log B

a. Sinistral fault
b. Dextral fault
c. Thrust fault
d. Normal fault
e. None of the above

A

c. Thrust fault

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Faults are fractures with discernable amounts of _
a. flak b. emplacement c. displacement d. disgrace e. derailment

A

c) displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Boudinage structures form by _____.
a. extension b. compression c. both a & b d. neither a nor b e. nota

A

a) extension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In a normal fault, the _____ is down thrown.
a. foot wall b. hanging wall c. block d. fault e. nota

A

b) hanging wall

Explanation:
In a normal fault, the hanging wall moves downward relative to the foot wall due to extensional forces, creating a sense of separation or stretching of the crust.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The layer where magma originates is
a. crust
b. mantle
c. inner core
d. outer core

A

b) mantle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In simple shear, parallel lines _______ after deformation:
a. become perpendicular b. remain parallel c. are unchanged d. become unparallel e. nota

A

b) remain parallel

Explanation:
In simple shear, parallel lines remain parallel after deformation, although they may change orientation and length. The deformation typically involves a change in shape without a change in volume, resulting in shear strain while maintaining the parallelism of lines.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The heave is a measured on a ______ plane.
a. vertical b. horizontal c. straight d. diagonal e. nota

A

b) horizontal

Explanation:
Heave is the horizontal displacement component of a fault, measured perpendicular to the fault plane. It represents the amount of lateral movement between two points across the fault.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The formula for quadratic elongation λ is:

A

λ = 1/cos²φ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The hanging wall in a thrust fault is ______
a. hanging b. downthrown c. loose d. upthrown e. nota

A

d. upthrown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Unloading Joints are ___to sigma 2.
a. perpendicular b. parallel c. diagonal d. oblique e. nota

A

b) parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The formula of elongation ε is _____.
a. ε = (1/cos φ) - 1
b. 1/(cos φ - 1)
c. 1/cos φ + 1
d. 1/cos φ
e. nota

A

a. ε = (1/cos φ) - 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What kind of fold is depicted in the following figure on the right?
a. True Anticline
b. True Syncline
c. Antiformal Syncline
d. Synformal Anticline

A

d. Synformal Anticline

“-cline” depends on the relative ages of the layers.
“–form” depends on the appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The formula for shear strain εᵪᵧ is _____.
a. cos φ
b. sin φ
c. cotan φ
d. a/b
e. b/a

A

c. cotan φ

17
Q

Match the items:

  1. Evaporite
  2. Coral
  3. Breccia
  4. Peat
  5. Shale
  6. Turbidite
  7. Oolites
  8. Sand
  9. Gravel
  10. Pelagic sediment

a) Grain size is 1/16-2 mm
b) Angular clasts in finer-grained matrix
c) Particle size is >2 mm
d) They form in abyssal fans
e) Caviar-sized and shaped particles
f) Organic sediment consisting of skeletal CaCO₃
g) Deep-sea sediments without terrigenous material
h) Fine-grained sedimentary rock exhibiting fissility
i) Deposited by drying up of the river or lake bed
j) Brown, lightweight unconsolidated deposit of plant material in wet bogs

A

Evaporite
What is evaporite?
Evaporite is deposited by drying up of the river or lake bed. (i)

Coral
What is coral?
Coral is an organic sediment consisting of skeletal CaCO₃. (f)

Breccia
What is breccia?
Breccia consists of angular clasts in a finer-grained matrix. (b)

Peat
What is peat?
Peat is a brown, lightweight unconsolidated deposit of plant material in wet bogs. (j)

Shale
What is shale?
Shale is a fine-grained sedimentary rock exhibiting fissility. (h)

Turbidite
What is turbidite?
Turbidite forms in abyssal fans. (d)

Oolites
What are oolites?
Oolites are caviar-sized and shaped particles. (e)

Sand
What is sand?
Sand has a grain size of 1/16-2 mm. (a)

Gravel
What is gravel?
Gravel has a particle size of >2 mm. (c)

Pelagic sediment
What is pelagic sediment?
Pelagic sediment is deep-sea sediment without terrigenous material. (g)

18
Q

The inflection point is where the change in _____ of a fold is observed.
a. length b. thickness c. shape d. curvature e. aota

A

d. curvature

19
Q

From which hemisphere did India come? .
a. East b. West c. South d. North e. nota

20
Q

Assign the beach ball symbols above to their proper representative geologic features.

a. 1: Normal Fault, 2: Oblique-slip Fault, 3: Reverse Fault, 4: Reverse Fault, 5: Strike-slip Fault
b. 1: Reverse Fault, 2: Reverse Fault, 3: Oblique-slip Fault, 4: Normal Fault, 5: Strike-slip Fault
c. 1: Reverse Fault, 2: Oblique-slip Fault, 3: Oblique-slip Fault, 4: Normal Fault, 5: Strike-slip Fault
d. 1: Strike-slip fault, 2: Oblique-slip Fault, 3: Oblique-slip Fault, 4: Strike Fault, 5: Dip-slip Fault
e. 1: Normal Fault, 2: Normal Fault, 3: Oblique-slip Fault, 4: Reverse Fault, 5: Strike-slip Fault

A

b. 1: Reverse Fault, 2: Reverse Fault, 3: Oblique-slip Fault, 4: Normal Fault, 5: Strike-slip Fault

Imagine that the material moves from white regions to shaded regions (white to shaded logic method).

21
Q

Referring to your answer in (1), specifically to your beach ball/s corresponding to strike-slip fault, what kind of strike-slip faults are they? Identify the fault strikes as well.

a. Dextral only (either NE-SW or NW-SE)
b. Sinistral only (either NE-SW or NW-SE)
c. Either dextral or sinistral (dextral: NW-SE; sinistral: NE-SW)
d. Either dextral or sinistral (dextral: NE-SW; sinistral: NW-SE)
e. Both the natures of strike-slip faults and their corresponding strikes are unidentifiable.

A

c. Either dextral or sinistral (dextral: NW-SE; sinistral: NE-SW)

Use the white to shaded logic method. Check that indeed, there are two possible strike-slip configurations for figure 5. White region 1 (on the N) may go to shaded region 1 (on W) or on shaded region 2 (E). If white region 1 -> shaded region 1, so the other side should follow: white region 2 -> shaded region 2. This forms a strike slip fault whose orientation is NE-SW. If we follow the other thinking: white region 1 -> shaded region 2 and white region 2 -> shaded region 1, there is a visualized strike – slip whose strike is now NW – SE. The strike is reflected by either NE-SW and NW-SE lines.

22
Q

Which of the figure numbers reflect a possible presence of thrust fault?
a. 1
b. 2
c. 3
d. 4
e. 5

A

b. 2

On figure 2: check the curves that separate the white and the shaded region. The less steeper curve (nearer to the plane of paper) corresponds to a lower dip of fault while the steeper curve (near the vertical) corresponds to a higher dip of fault. So the area could have a high or a low dip (thrust fault). Figure 1 does have two curves that are steep, so we do not expect a thrust fault here.

23
Q

The __ axis bisects shear joints
a. σ₁
b. σ₂
c. σ₃
d. σ₁ and σ₂
e. nota

24
Q

The crust can be 0 km in thickness.
a. False b. Can’t say 0. True d. nota

25
Q

is a symbol for
a) overturned fold striking 80°N
b) asymmetrical fold plunging 80°
c) overturned bed dipping 80°
d) rotational fault dipping 80°
e) syncline with 80° plunge.

A

e) syncline with 80° plunge.