Plate tectonics
G2 Elective Geography: Tectonics - syllabus K229, 2027
Why plates move, how we know, and how landscapes form.
- Earth's layers and tectonic plates
A tectonic plate is a moving piece of Earth's outer shell, made of crust and the rigid top of the mantle.
- Why tectonic plates move
Slow circulation in the mantle and the pull of sinking ocean plates move tectonic plates.
- Seafloor spreading
New ocean crust forms at mid-ocean ridges and moves away, so rocks get older the farther they are from the ridge.
- Magnetic striping
Cooling basalt records Earth's magnetic field, and matching stripes on both sides of a ridge prove seafloor spreading.
- Plate boundaries
How plates move, and what type they are, decides whether a boundary makes new crust, subduction zones, mountains or faults.
What you will be able to do
I can describe Earth's layers and explain how convection and slab pull move tectonic plates.
Syllabus K229, Topic 3.1, Key Question 1. What is the plate tectoni theory?
Taught in Earth's layers and tectonic plates, Why tectonic plates move
I can use rock ages and sediment evidence to explain how seafloor spreading supports plate tectonic theory.
Syllabus K229, Topic 3.1, Key Question 2. How does seafloor spreading support the plate tectonic theory?
Taught in Seafloor spreading
I can explain how magnetic striping on the seafloor supports plate tectonic theory.
Syllabus K229, Topic 3.1, Key Question 3. How does magnetic striping support the plat tectonic theory?
Taught in Magnetic striping
I can explain what forms when plates move apart, collide or slide past each other.
Syllabus K229, Topic 3.1, Key Question 4. What happens at plate boundaries when tectonic plates move?
Taught in Plate boundaries