Tidl. eks

Question 1

Name a primary structure

Answer 1

Cross-bedding

Question 2

What is stress?

Answer 2

It is force per unit area

Question 3

What is brittle deformation typical of?

Answer 3

Low temperatures and pressures in the upper crust

Question 4

Normal faults usually form in stressystems in which:

Answer 4

sigma 2 i horizontal (and 3)

sigma 1 is vertical

Question 5

A later fault will have the following relationship to an earlier fault:

Answer 5

The later fault will cut the older fault

Question 6

The length of a fault is usually roughly proportional to:

Answer 6

Maximum displacement on the fault

Question 7

What are components of deformation?

Answer 7

Rotation, translation and strain

Question 8

What is characteristic of homogeneous strain?

Answer 8

Straight and parallel lines remain straight and parallel

Question 9

What is true about relationship between strain and stress?

Answer 9

Strain CAN be proportional to stress (elastic)

Question 10

What effect does fluids have on rock strength?

Answer 10

Fluids decrease rock strength

Question 11

Where would cataclastic rocks generally tend to develop?

Answer 11

Along faults in the upper crust

Question 12

What types of fault systems tend to act as precursors to the separation of plates and the development of oceanic crust?

Answer 12

Rifts

Question 13

What fault geometries are characteristic of horsts and grabens?

Answer 13

Conjugate normal faults

Question 14

Why are earthquakes more likely to occur in the upper crust than in the lower crust?

Answer 14

The upper crust is dominated by brittle deformation

Question 15

What is true about rheology and rocks?

Answer 15

All rocks can flow

Question 16

Where do damage zones characteristically develop?

Answer 16

Around fault plantes

Question 17

Why is it important to show a hammer or person on field photographs?

Answer 17

It shows the scale of the structures.

Question 18

Geometric descriptors of geological structures include

Answer 18

Size, shape and orientation

Question 19

Normal faults usually form in stress systems in which:

Answer 19

sigma 2 is horizontal, sigma 3

sigma 1 is vertical

Question 20

Relay ramps occur at which locations?

Answer 20

Between two normal faults that step in map view

Question 21

Which shape can be used to represent stresses and strain?

Answer 21

Ellipsoid

Question 22

What is characteristic of ductile deformation?

Answer 22

There is strain without macroscopically visible fractures

Question 23

Where can rocks be strongest?

Answer 23

The mantle, dry rocks are the strongest

Question 24

What is the best way to quantify the strain across a rift system?

Answer 24

Amount of extension?

Question 25

What cannot be used to infer the orientation of present day stresses?

Answer 25

Gravity and magnetic data?

Question 26

What is true about perfectly viscous fluids?

Answer 26

Strain rate proportional to applied stress, permanent deformation, strain is time-dependent