Earth's crust Flashcards
Science study (30 cards)
What is compression?
Stress that squeezes rock
What does compression do to rocks?
Folds or breaks it
What is a fault?
A break in earths crust
Where do faults happen?
Along plate boundaries
What is a rock fold?
A bend in a rock caused by compression and reverse faults
How do folds in rock form?
Compression stress forcing 2 blocks of rock together.
How do rock folds change the shape of rocks?
Shortens and thickens earths crust
What is a footwall?
A block of rock below the fault line.
What is a hanging wall?
A block of rock that lies above the fault line
What is a normal fault?
A type of fault that occurs when rocks are pulled apart. Making the hanging wall slide down relative to the footwall.
What stress causes normal faults?
Tension
What is a reverse fault?
A type of fault that occurs when rocks are squeezed together. Making the hanging wall move up relative to the footwall.
What stress causes a reverse fault?
Compression
What is a strike-slip fault?
A type of fault that occurs what rocks move side to side against each other with little up or down motion.
What type of stress causes a strike-slip fault?
Shearing
What is stress?
A force that adds energy to rocks to change its shape or volume.
What is force?
A push or pull
What are tectonic plates?
Huge slabs of movable rock under earths surface.
How do tectonic plates move?
Heat from earths mantle force these plates to towards, away from, or alongside each other at very slow speeds.
What can moving tectonic plates do to the earths crust?
Over millions of years, plate movement can cause earths crust to fold, bend, and break.
What is tension?
Tension is a pulling force.
What does tension do to rocks?
Pulls rocks, stretching it and thinning the rock.
What are 3 types of stress?
Tension, Compression, and Shearing.
What are 3 types of faults?
Normal, Reverse, ans Strike-slip fault.
