Science Explorer: Focus on Earth Science. Chpt 2/Sect 1 Flashcards
(13 cards)
Name the three types of stress?
Tension
Compression
Shearing.
How do stress forces affect rock?
Stress forces change it’s shape or volume. Also adds energy to the rock.
How does shearing force affect rock?
Pushes rock in two opposite directions
What type of faults does shearing cause?
Strike-slip faults
What type of faults does compression cause?
Reverse faults
What type of fault does tension cause?
Normal fault.
Describe the movement along a strike-slip fault.
Rocks slip past each other sideways with little up-or-down motion.
Ex- San Andreas in CA
Describe the movement along a normal fault
Two blocks slide past each other along an angle.
Hanging wall - starts higher and slides down
Foot wall - starts lower and slides up.
Ex - Rio Grande valley
Describe the movement along a reverse fault
Two blocks slip past each other along an angled fault line
Hanging wall - starts lower and slips upward
Foot wall - starts higher and slips downward.
Describe mountains formed by faulting
Tension forms two parallel normal faults which lift a block in the middle to form mountains.
Describe mountains formed by folding
Compression causes the crust to fold upward and form mountains.
ex - Alps in Europe and Himalayas in Asia
Define an anticline
Upward folds in rock caused by compression/folding.
Define syncline
The downward folds caused by compression/folding. Forms a bowl.
