Plate Tectonic Theory Flashcards
What are Plates?
The Earth’s crust and upper mantle (Lithosphere) are broken into sections called plates
Plates move around on top of the mantle like rafts
What is the Theory of Plate Tectonics?
Pieces of Earth’s lithosphere are in constant motion, driven by convection currents in the mantle.
Plates move slowly in different directions
Cause different geologic events (like earthquake, volcano, etc.)
What makes plates move?
Convection Currents in the mantle move the plates as the core heats the slowly-flowing asthenosphere (the elastic/plastic-like part of the mantle).
What are plate boundaries?
The edges of Earth’s plates meet at plate boundaries.
Extended deep into the lithosphere
What is a Fault?
Breaks in Earth’s crust where rocks have slipped past each other.
What are the three types of boundaries?
Divergent Boundaries
Convergent Boundaries
Transform Boundaries
Divergent Boundaries
A plate boundary where two plates move away from each other.
RIFTING causes SEAFLOOR SPREADING
“dissecting” or “dividing”
If you pull warm bubble gum or silly putty, it will thin in the middle until it is stressed so much that it breaks.
Happens on land or in water
How is the rock pulled at Divergent Boundaries?
Rock gets THIN in the middle as it is pulled apart.
Stress is called Tension
What happens when the rock SNAPS from the Stress of Tension?
Tension stress is being pulled apart
A Normal Fault (fault is a break in Earth’s crust)
Rock drops down as it breaks
Features of Divergent Boundaries
Mid-ocean ridges
rift valleys
fissure volcanoes
Where are the youngest rocks?
Under water
Seafloor Spreading
The process where new oceanic crust is formed at mid-ocean ridges and spreads outward, pushing older crust away from the ridge
In Mindcraft, Lava + water = Obsidian
What things rely on things that occur at/near divergent boundaries?
Tubeworms, Chemosynthetic Bacteria, and more
Need:
Heat
Minerals
Other Chemicals
How is the rock pushed at convergent boundaries?
A plate boundary where two plates move towards each other.
Boundaries between two plates that are colliding
Called Compression
Convergent Boundaries
Places where plates crash (or crunch) together or subduct (one sinks under)
Compression