Earth Structure

Question 1

Ductile deformation

Answer 1

A solid-state flow that results in a change in size and shape of rocks without fracturing. Occurs in high temperature and pressure environment.

Question 2

Folds

Answer 2

Flat-lying sedimentary and volcanic rocks bent into a series of wavelike undulations. Result of compressional stresses.

• anticlines: unfolding
• syncline: downfolded

Question 3

Dome

Answer 3

Circular or slightly elongated, up-warped displacement of rocks, oldest rocks in core

Question 4

Basin

Answer 4

Circular or slightly elongated, down-warped displacement of rocks, youngest rocks in core

Question 5

Faults

Answer 5

Fractures (breaks) in rocks along which appreciable displacement had taken place

Question 6

Dip-slip faults

Answer 6

Faults in which movement is primarily vertical. Movement along inclination (dip) of fault plane.

Question 7

Normal faults

Answer 7

Hanging wall block moves down relative to the foot wall block caused by tension all forces

Question 8

Reverse faults and thrust faults

Answer 8

Dip-slip faults in which the hanging wall block moves up relative to the foot wall block caused by compressional stresses.

• reverse faults >45 degrees
• thrust faults

Question 9

Strike-slip faults

Answer 9

Faults in which the dominant displacement is horizontal and parallel to the trend or strike of the fault surface.

Question 10

Transform faults

Answer 10

Large strike-slip faults that cut through lithosphere-often associated with plate boundaries

Question 11

Joints

Answer 11

Fractures along which no appreciable displacement has occurred. Most are result of brittle failure of rock units located in outermost crust.

Question 12

Deformation

Answer 12

Changes in shape and volume of a rock body.