L3. CRUSTAL DEFORMATION AND THE SEAFLOOR SPREADING HYPOTHESIS

Question 1

It is is defined as the force per
unit area applied on rock.

Answer 1

Stress

Question 2

It is also referred to as deformation, is defined as the change in shape or volume of the rock caused by stress.

Answer 2

Strain

Question 3

It is a wavelike appearance that is observed in rock that is exposed to constant stress.

Answer 3

Fold

Question 4

KINDS OF STRESS

Common in places where there is converging plates and rocks are being squeezed.

Answer 4

Compressional Stress

Question 5

KINDS OF STRESS

Common in diverging plate boundaries where rocks are being pulled apart.

Answer 5

Tensional Stress

Question 6

KINDS OF STRESS

Usually observed in transform plate boundaries where plates move side by side. In this, rocks are subjected to forces in opposite directions that are parallel to its plane.

Answer 6

Shear Stress

Question 7

STAGES OF DEFORMATION

It is the first stage of deformation. In this stage, deformation is still reversible. Rock layers may return to its original shape once stress is removed.

Answer 7

Elastic Deformation

Question 8

STAGES OF DEFORMATION

In this stage rocks is described to behave like plastic where they may be bent or be deformed without breaking its continuity

Answer 8

Ductile Deformation

Question 9

STAGES OF DEFORMATION

It happens when rocks deformed are fractured or broken. Both ductile and brittle deformation are irreversible. Rocks that undergone these stages will not return to its original shape or volume after these.

Answer 9

Brittle Deformation

Question 10

This may form during ductile deformation caused by compressional and shear stress.

Answer 10

Fold

Question 11

It is any break in the rock layer caused by stress.

Answer 11

Fracture

Question 12

A fracture will be described as a _______ when movement between the broken rock layer is visible.

Answer 12

Fault

Question 13

A fracture will be called as a ________ if there is no visible movement between the broken rock layer.

Answer 13

Joint

Question 14

These are those processes that are primarily driven by the solar energy

Answer 14

Exogenic Processes

Question 15

These are driven by the forces originating deep within the Earth.

Answer 15

Endogenic processes

Question 16

This is a theory that suggests the continents were once part of an enormous landmass, Pangaea, and that it is moving through the oceans and sometimes collide with other continents.

Answer 16

Continental Drift Theory

Question 17

Who proposed the Continental Drift Theory?

Answer 17

Alfred Wegener

Question 18

What were Alfred Wegener’s evidences that supported the Continental Drift Theory? (3)

Answer 18

1. Fit of the continents
2. Distribution of Fossils
3. Evidences of tropical climates and glaciation

Question 19

This claims that younger seafloor is formed when molten material spewed from the mid-ocean ridges pushes the seafloor away from the ridges. As the lava cools, it turns into younger seafloor and the pushed seafloor tends to subside as it makes contact with denser continental crust.

Answer 19

Seafloor Spreading Hypothesis

Question 20

What are the evidences that support the Seafloor Spreading Hypothesis? (4)

Answer 20

1.Seafloor’s topographic features
2. Concentration of tectonic activities
3. Age of the seafloor
4. Magnetic striping of the seafloor