Forces In Earths Crust Flashcards
Which type of stress causes the crust to become thinner?
Tension
What are the three types of stress that occur in Earth’s crust?
Tension
Compression
Shearing
Any force that acts on a rock to change its shape or volume
Stress
Pulls on the crust, stretching rock so that it becomes thinner in the middle
Tension
Squeezes rock until it folds of breaks
Compression
Pushes a mass of rock in two opposite directions
Shearing
A fault in which one part of the rock is above another part and slips downward when movement occurs
Normal fault
The block of rock that lies above the fault
Hanging wall
The rock that lies below a fault
Footwall
Has the same structure as a normal fault but blocks move in opposite directions
Reverse fault
The rock on either side of the fault slip past each other sideways with little up and down motion
Strike-slip fault
Rock that bends upward into an arch
Anticline
A fold in rock that bends downward to form a valley
Syncline
A large area of flat land elevated high above sea level
Plateau
What is the effect of tension?
Rock becomes thinner in the middle
What is the effect of compression?
Rock folds of breaks
What is the effect of shearing?
Rock breaks and slips or changes shape
A break in earths crust
Fault
The hanging wall slides up and over the Footwall
Reverse fault
There is little up and down motion
Strike-slip fault
The hanging wall slips downward below the Footwall
Normal fault
A strike slip fault that forms the boundary between two plates is what type of boundary?
Transform boundary
What two types of faults can result in mountains?
Normal and reverse, both have vertical movement that can push up rock
What is an example of a reverse fault?
Rocky Mountains
What is an example of a strike-skip fault?
San Andreas fault
What is an example of a normal fault?
Rio Grande Rift Valley
Parallel ridges and valleys
Folded mountains
How is a fault-block mountain created?
By two normal faults
What are examples of mountain ranges created by faults?
Alps, Himalayas, Appalachian
Why do faults often occur along plate boundaries?
The force of plate motion push or pull the crust so much that the crust breaks
What are three landforms created by compression in the crust?
Mountains, volcanoes, plateaus
